Electromagnetic Radiation Meters

How to choose a radon monitor to measure the dangerous radioactive gas in your home

Easily measure the radon levels accumulated in your home from soil and building materials with easy to use new technology digital alpha particle monitors. Which measuring devices we recommend.

Not the type of meter you are looking for? Please check our guides on low frequency meters (measure radiation from power lines, cables, transformers, electric devices laptops etc), high frequency meters (measure radiation from cordless phones, wireless modems (Wi-Fi), cell phone masts etc), radioactivity meters (measure beta, gamma, X ray radiation from subsoil, food, building materials, tiles, granite counters, nuclear accidents, ionization smoke detectors, medical equipment etc) or check the frequently asked questions about electromagnetic field meters!

We advise you to read all the following information about how to use a radioactivity meter and which are the important features to look for, but if you are in a hurry to see the recommended meters go straight to the radiation meters comparison table at the end of the article.

 What do radon monitors measure?

radonhomeRadon meters, alpha particle counters, detectors, dosimeters and monitors measure the concentration of the radioactive radon gas which is emitted from the soil, enters buildings by pipes and cracks and is the main source of population exposure to ionizing radiation.

Why is measuring radon important?

Radon has been added to list of the proven carcinogens (Group 1 human carcinogen) by the International Agency for Research on Cancer (IARC - International Agency for Research on Cancer) since 1988 and according to the World Health Organization (WΗΟ, Radon and cancer):

  • Radon is, after smoking, the second most important cause of lung cancer in many countries.
  • Causes of between 3% and 14% of all lung cancers.
  • It is the leading cause of lung cancer in non-smokers.
  • The lower the concentration of radon in a home, the lower the risk.
  • There is no threshold below which radon exposures carries no risk.
  • The likelihood of lung cancer increases by 16% for each 100 Bq / m3 increase in the concentration of radon!

In the European Union, lung cancer is the most common cause (about 20%) of cancer death (Radon Prevention and Remediation (RADPAR) funded from the European Commission DG SANCO Second Public Health Programme).

Based on epidemiological investigations in nine EU countries it was estimated that approximately 9% of deaths from lung cancer may be due to exposure to radon in the home.

Read more about radioactivity and its effects..

Where are higher levels of radon recorded?

Higher radon values are recorded in the lower floors of buildings in places with poor ventilation, caves, hot springs, mines and other underground spaces and near high or medium voltage cables (the elevated electric field values increase up to 18 times the accumulation of radon particles (Henshaw DL, Ross AN, Fews AP, Preece AW., Enhanced deposition of radon daughter nuclei in the vicinity of power frequency electromagnetic fields., Physics Laboratory, University of Bristol).

Some areas have more elevated radon levels than others due to subsoil or due the building materials used in the area. Radon maps of various areas are available online.

The current energy saving practice of using air-tight doors, windows and other building materials for thermal insulation purposes increases the concentration of radon in modern homes. 

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What features to look for in a radon meter

Manufacturer

A reputable company or country of manufacture could mean better quality and extended operating life. Being more geographically close might be helpful if there is a malfunction of the meter or you need to send it back for recalibration.

Average price

This is the average price of the meter sold by the various online sellers shown on the bottom of each table.

Detector type

The main types of radon detectors are active and passive.

Passive radon detectors such as cheap charcoal canisters accumulate gas over a specified period of type (usually over one month) and then are shipped to a laboratory for analysis.

The problem with such detectors is that they are disposable and their supply must be constantly replenished, they require extra handling to ship the dosimeter to a laboratory and thus require additional wait times to receive analysis results.

On the other hand active radon testing devices such as radon monitors are a better choice today since they continuously display average radon concentration and can give us an estimation of radon concentration more quickly (at least after 5 days).

The way most digital radon monitors detect radon though the use of ionization chambers and photodiodes, like traditional alpha track detectors, is explained by Corentium, a popular manufacturer of radon monitors:

"The detection of radon is based on the principle that radon gas diffuses into a detection chamber. When the radon atoms decay they emit energetic alpha particles. The alpha particles are detected by a silicon photo diode.

Every alpha particle generates a small signal current when it hits the photo diode. By the use of a low-power amplifier stage the signal current is converted into a larger voltage signal. The maximum amplitude of the voltage signal is detected and sampled by an analog to digital converter (ADC). The amplitude is proportional to the energy of the alpha particle that hit the photo diode.

The brain of the monitor is a micro-controller that registers the time and energy of every detected particle. This information is used to calculate the mean radon gas concentration for daily, weekly and yearly periods."

Units of measurement

Radon monitors record the radon concentration per cubic meter in Bq / m3 where Becquerel (Bq) is the number of radioactive disintegrations per second or in pCi/lt (pico-curie per liter), where 1 pCi/lt = 37 Bq/m3.

Measurement range

We recommend the radon monitor to be able to measure up to 1000 Bq / m3 or 27 pCi/lt (most recommended safety levels are <400 Bq / m3 or 10 pCi/lt).

What are the safe levels of exposure to radon?

According to the World Health Organization (WHO, Radon and cancer) there is no threshold below which radon exposures carries no risk and the likelihood of lung cancer increases by 16% per 100 Bq/m3 or 2.7 pCi/lt increase in radon concentration!

The average radon concentration values differ from region to region and are higher indoors! In USA the average values are 15 Bq / m3 or 0.4 pCi/lt outdoors and 50 Bq / m3 or 1.3 pCi/lt indoors (US Environmental Protection Agency, A Citizen's Guide to Radon).

The officially recommended exposure limits are:

  • European Union (proposed for existing buildings): 400 Bq / m3 or 10 pCi/lt (European Commission - reference by Radon Legislation and National Guidelines, Swedish Radiation Protection Institute)
  • European Union (recommended for new buildings): 200 Bq / m3 or 5 pCi/lt
  • US Environmental Protection Agency (EPA): 150 Bq / m3 or 4 pCi/lt
  • German Institute for Building Biology (IBN = Institut für Baubiologie + Ökologie Neubeuern): very strong> 200 Bq / m3 or 5 pCi/lt
  • World Health Organization: 100 Bq / m3 or 2.7 pCi/lt

The World Health Organization is very alarming about the dangerous radon levels and recommends the lowest safety limits in its report WHO HANDBOOK ON INDOOR RADON: “It is recommended to set a national reference level as low as reasonably achievable. In view of the latest scientific data on health effects of indoor radon a reference level of 100 Bq/m3 is justified from a public health perspective because an effective reduction of radon-associated health hazards for a population is herewith expected.”

Data logging

Most radon monitors do not offer data logging but continually store measurements and show us the daily, weekly or yearly averages.

Display

A digital display gives you more accurate readings and has a more modern and professional look.

Backlight display

Not a necessary feature.

Audio alarm

Audio alarm warns you when the set alarm threshold has been exceeded.

Accuracy

Higher accuracy is good but it is more important for professional users and not for amateurs.

Batteries and battery life

If you plan to use the meter a lot then you should definitely take into account the battery type and life of the batteries used, because changing batteries frequently could elevate the operating cost significantly. Some meters are rechargeable or come with their own power cord so you don’t have to purchase new batteries every little while.

Carrying case

A good quality plastic case is very helpful for professionals or for those who frequently measurements in various locations.

Calibration service

If you need to check that everything works well in the future you might consider sending it for calibration (or recalibration if the meter was originally calibrated). This is especially important for professional users. In that case you should choose a manufacturer that offers this service. Also it would be better if the manufacturer is geographically close to you.

Warranty

The longer the warranty the better, especially if the meter is expensive.

Seller

We try to we recommend reputable companies, with good customer service, that can ship the meters worldwide.

Being more geographically close might be helpful if there is a malfunction of the meter, so we usually recommend one seller from the USA and one from Europe.

Also, buying from an overseas company means there will be some extra shipping costs and possible tax charges in the customs office.

Finally, please be sure to check all the mentioned features (warranty, prices etc) also in the sellers page, because they could be different from those mentioned in the following comparison tables or have changed since the time this article was written.

Check all recommended radon meters in the comparison table below:

How to choose high and low frequency combination EMF meters and packs

Are there meters that measure all basic types of radiation? Which are the best? Why you should choose such a type of meter and why you should avoid it. How to alternately choose a combination of meters to measure high and low frequency electric, magnetic and electromagnetic fields.

Not the type of meter you are looking for? Please check our separate guides on high frequency meters (measure radiation from from cordless phones, wireless modems (Wi-Fi), cell phone masts etc), low frequency meters (measure radiation from cables, power lines, transformers etc) radioactivity meters (measure radiation from radon gas, granite counters, nuclear accidents etc) or check the frequently asked questions about electromagnetic field meters!

Is there really a meter that measures all types of radiation?

Well, this is what every amateur user is looking for when searching for a meter.

One meter that will measure:

  • low frequency magnetic fields (non ionizing radiation from power lines, transformers etc)
  • low frequency electric fields (non ionizing radiation from electrical cables, devices, etc)
  • high frequency electromagnetic fields (non ionizing radiation from wireless phones, cell phones masts etc)
  • radioactivity (ionizing radiation from nuclear power, granite tiles, soil etc)

But so far there are no meters that measure all types of radiation, but there are meters that measure only non-ionizing radiation (the first 3 types above), the basic artificial electromagnetic fields that are the main part of electrosmog today.

So when we refer to combination meters this is what we mean: all major types of radiation except radioactivity.

So do combination meters work?

Combination meters are great because you only need one to carry around for your basic emf measurements.

Also, they usually cost a lot less compared to buying 2-3 different meters to do the same measurements.

On the other hand combination meters tend not to perform well in all types of measurements.

Some times their performance in specific measurements is really terrible, so try to read their specifications and our comments in the comparison tables at the end of this article before you decide to buy one of them.

The only combination meter that seems to perform well in the 3 basic measurements (low frequency electric and magnetic, high frequency electromagnetic) is the new Trifield TF2 meter.

What do experts say about combination meters?

The German Consumer Protection Organization (WILA Bonn) commissioned IMST GmbH (an accredited EMC testing facility in Germany) to test low cost meters.

The German report Electrosmog meters put to the test concluded that:

“It is good to maintain a healthy skepticism toward offers that promise amazing performance at extremely favorable prices.

And it is always good to remember that professional testing equipment never combines RF and ELF measurement probes in one single meter or fits an RF antenna into the meter casing.

Antennas/probes that are integrated into the meter casing are also a great source of errors.

Prefer meters with a digital display and an external measurement antenna. A highly directional logarithmic-periodic antenna (which looks like a Christmas tree or fish skeleton) is very useful in determining the direction from where the RF radiation originates."

So this means that combining more antennas/sensor to a small casing makes the measurements problematic.

This is especially true for high frequency measurements were an external, directional or isotropic antenna makes a huge difference.

So what do you recommend?

For practical and for economic reasons you can buy a combination meter.

Combination meters are also a good choice when you want to buy an introductory meter to understand basic measurements, before you buy a better meter. Choose a combination meter from the comparison tables below.

For more correct, accurate and reliable measurements you should invest in separate higher quality meters.

This is especially true for professional users, who will also make a bad impression to their clients when performing all the measurements with only one meter.

For those who want to really measure electromagnetic fields, we suggest you choose one of the meters packs presented below.

The list of high and low frequency meter packs is not exhaustive, you can create your own pack based on your needs.

You can see all the meters you can combine in the in the low frequency meters and high frequency meters articles.

The packs are presented starting with those that offer the most features to those that offer the least ones.

Some companies like Gigahertz Solutions, offer better prices for their packs compared to buying each of their meters individually.

Triple axis low frequency magnetic with data logging / Triple axis low frequency electric / High frequency electromagnetic

Best pack

NFA1000+HFE59B (directional and omindirectional antenna - also offers data logging for high frequency measurements)

Price:~ 3500$ (sold with 250$ discount as ELECTROSMOG MEASURING KIT MK70-3D)

Economic pack

NFA1000+HFE35C (directional and omindirectional antenna)

Price:~ 2700$

Triple axis low frequency magnetic with data logging / Single axis low frequency electric / High frequency electromagnetic

Best pack

NFA400+HF59B (directional and omindirectional high frequency antenna - also offers data logging for high frequency measurements)

Price:~ 2800$

Good packs

NFA400+HFE35C (directional and omindirectional high frequency antenna)

Price:~ 2000$

NFA30M+ME3030B+ HFE35C (directional and omindirectional high frequency antenna)

Price:~ 1600$

Economic packs

TM-192D+ GM3120+HF35C (directional high frequency antenna)

Price:~ 550$

TM-192D+ GM3120+TM195 (triple axis high frequency antenna)

Price:~ 450$

TM-192D+ GM3120+ED-15C (single axis high frequency antenna)

Price:~ 340$

Triple axis low frequency magnetic / Single axis low frequency electric / High frequency electromagnetic

Good pack

MT-263+ ME3030B+HF35C (directional high frequency antenna)

Price:~ 710$

Economic packs

TM-190 and Trifield TF2 (single axis high frequency antenna) These are the only combination meters that can fit to this category alone!

Price:~ 200$

Single axis low frequency magnetic / Single axis low frequency electric / High frequency electromagnetic

Good pack

ME3030B+ HF32D (directional high frequency antenna)

Price:~ 350$ (sold with 30$ discount as ELECTROSMOG MEASURING KIT MK10)

In this last category where we are looking for only basic features, we can indeed do our work also with the combination meters that follow.

Check all combination meters in the comparison tables below:

How to measure electromagnetic radiation - EMF meter selection guide

How to choose an EMF meter? Which features to look out for and for which you should avoid overpaying? How to use them – user manuals and great videos! Is there a device that measures all types of radiation? Are radiation measurements only needed when there is a significant radiation source nearby? Which radiation values are considered high and where are they usually recorded? What methods of protection are available if you find elevated prices? The last web page you are going to visit before you buy electromagnetic radiation meters!

What do radiation meters measure?

EMF (electromagnetic fields) or EMR (electromagnetic radiaton) meters are divided into 3 main categories according to the type of the radiation they measure:

  • Low frequency radiation meters measure electric and magnetic fields from electrical and electronic devices, power cables and transformers etc.
  • High frequency radiation meters measure electromagnetic fields (radio waves, micro waves etc) from cell phones and cell phone masts, wireless internet, cordless phones, bluetooth devices, alarm systems, microwave ovens, wireless game consoles, TV and radio broadcasting antennas, radars, police communications etc.
  • Radioactivity meters measure a and b particles, gamma and X rays from granite tiles, medical equipment, radon gas, subsoil, nuclear accidents etc. (especially for radon measurements we recommend you choose a radon monitor instead of a general use radioactivity geiger type counter)

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Where do we usually record elevated electromagnetic fields?

  • In densely populated areas because of the presence of more mobile antennas, greater power consumption and more dense power distribution network
  • In houses where the low voltage cables are situated near high use areas (bedrooms, living rooms etc.)
  • In residences adjacent to mobile phone masts, power lines and transformers
  • In offices because of the multitude of electronic and wireless devices
  • In apartments due to the presence of a multitude of wireless phones and wi-fi modems
  • In older homes due to wiring problems
  • On the upper floors of buildings due to increased exposure to high frequency antennas
  • In the lower floors with insufficient ventilation due to elevated levels of radon

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Which radiation values are high?

You can read the proposed safe levels of exposure to each type of radiation in our low frequency, high frequency and radioactivity meters guides or in our article about the proposed and legal safe levels of radiation..

How can a radiation meter help me reduce my radiation exposure?

  • You will identify the obvious or hidden radiation sources around you so that you can remove or replace them
  • You will avoid radiation hotspots (were the limits of safe long-term exposure to high frequency radiation are exceeded) by increasing your distance from the radiation source.
  • You will see if you have achieved low radiation levels in your areas after using electromagnetic shielding materials or implementing other solutions proposed in our radiation reduction tips guide.

It is easy to measure electromagnetic fields on my own?

Since radiation measurements have become mainstream the past years, the majority of EMF meters (and all the meters we recommend) are very simple to use and do not require any technical knowledge.

How do you choose the meters you recommend?

There are dozens EMF meter manufacturers, selling hundreds different EMF meters, from every corner of the world.

How did we end up recommending only a few of them?

Well…

Home Biology is run by engineers who perform electromagnetic radiation measurements for a living.

We know what features you to need to look for when buying an EMF meter, so that you can easily and reliably take the necessary measurements, without overspending.

We’ve got everything covered! Just read on and choose the meter you like!

Thinks we consider before recommending a meter…

  • Frequency range

Does it cover the frequency range of the most common radiation sources?

  • Measurement span

Does it measure even low radiation values so that you can compare them to even the lowest recommend safety limits?

Does it measure high enough values so that you can record the radiation from the majority of the high radiation sources?

  • Necessary features

Does it offer the basic features needed to perform an EMF measurement?

  • Price

Does it offer the same features but with a lower price than other similar meters?

  • Ease of use

Is it simple to use, without confusing lights, buttons and directions of use?

  • Ability to detect radiation sources

Does it help you find which radiation sources affect you or were their location is (by using audio signal, directional antenna etc)?

  • Manufacturer

Is it manufactured by a reputable company with real factories, personnel , email, phone and website? Good luck with finding the manufacturers of some of the cheapest china made meters on the market…

  • Warranty

Does it come with at least a year of real and binding warranty, so that you can have it replaced or repaired if there is a problem?

  • Seller

Is it sold by trusted sellers with good customer service, that can ship the meters worldwide?

  • Helpfull manuals or videos

Does it have easy to read English manuals and/or videos of real use online?

Unfortunately most meters in the market do not include one or all of the above basic features. All these above factors are analyzed in our high frequency meter, low frequency meter and radioactivity meter guides. Please read them carefully before you purchase!

radiationmeters

How can i measure radiation from cell towers, cordless phones, Wi-Fi modems, tablets, smartphones, baby monitors, microwave ovens etc.?

You will need a high frequency (=wireless) radiation meter which measures electromagnetic field power density (in mW/m2 = milliwatts per square meter = 1000 μW/m2 = 1000 uW/m2 = 1000 microwatts per square meter) or high frequency electric field intensity (in V/m), or both.

High frequency meters should be able to record radiation in the frequency range 800-2500MHz (at least) which most modern wireless radiation sources emit.

Some have an antenna attached that can help you locate the direction fo the radiation, others produce different sounds according to the radiation source, others have both features.

Learn more about high frequency radiation meters, sources and safety limits..

How can i measure radiation from power cables, transformers, pylons, electrical devices etc.?

You will need a low frequency radiation meter which measures low frequency magnetic and/or electric fields from all wired radiation sources.

All wired radiation sources connected to the power network generate electrical alternative current (AC) fields due to electrical voltage. When electrical current flows through the conductors (when there is electricity consumption) AC magnetic fields are also produced.

Low frequency meters should be able to record radiation in the frequency range 50-60Hz (at least) which is the main frequencies of electrical grids.

Magnetic field meters measure magnetic field flux density in nT (= nano Tesla) or mG (= milli gauss = 100nT). Magnetic fields penetrate unaffected almost all building materials and the most common cause of elevated values ​​are the low voltage power cables, especially in densely populated areas.

Measuring magnetic fields is, in our opinion, the most important measurment you should take before buying or renting property, because high magnetic fields are difficult and expensive to reduce.

Electric field meters measure electric field density in V/m (= Volt per meter) or Body Voltage in mV (= milli volt). Electric fields are elevated near high voltage cables, but do not enter the interior of the buildings because they are grounded from most building materials (except from glass or wood). Inside the buildings electric fields are produced mainly form the in wall cables anf the electricl appliances that are plugged in.

Low frequency electric field measurements are indicated in areas such as bedrooms, where continuous power supply of devices and circuits is not necessary. Also the presence of high electric fields ia probably more aggravated during night sleep./p>

Learn more about low frequency radiation meters, sources and safety limits...

How can i measure radioactivity from building materials, nuclear accidents, medical equipment, radon etc.?

The radioactivity or ionizing radiation meters measure the radiation from radioactive materials (subsoil, food, building materials, tiles, granite counters, nuclear accidents, ionization smoke detectors, medical equipment etc.) and from the radioactive radon gas that is emitted from the soil, enters the buildings from pipes and cracks, accumulates especially in low floors with inadequate ventilation and is the most common source of radioactivity exposure.

Radioactivity meters

Radioactivity meters usually contain a Geiger - Muller tube which records the effective dose rate of radioactivity in μSv/h ( = uSv/hr = micro sivert per hour) from building materials (granite etc.), nuclear accidents, medical equipment etc.

Most Geiger counters measure only gamma radiation, some additionaly measure X-rays and beta particles.

They usually cannot measure alpha particles which are emmited by radon.

Radon meters

The radioactive radon gas is emitted from the soil, is the main source of population exposure to radioactivity, and is listed as a proven carcinogen by the Wolrd Health Organization.

Radon meters measure the concentration of radon per cubic meter (in Bq / m3), were Bq = Becquerel = the number of radioactive disintegrations per second.

Learn more about radioactivity - geiger meters, sources and safety limits...

Learn more about radon meters, sources and safety limits...

How can I measure geopathic radiation?

Geopathic fields are non artificial fields believed to be emitted from the earth. These are separated into water, Ley, Hartmann, Curry lines etc. Their existence today is disputed and / or considered insignificant in relation to strong electromagnetic fields from modern artificial radiation sources (antennas, transformers, cables, etc.).

Also, there is yet to be found a scientific commonly accepted way of measuring them.

To identify them the main way used is still dowsing by people who have the ability to feel ethereal or earthy fields (radiaesthesis). Some research has been done on the subject (Betz, Hans D .: Journal of Scientific Exploration 8: 436, 1994, Recent results on water dowsing / Maes W: Radiästheten im Test. Wohnung und Gesundheit 58; 1991) and our personal experience (the writer of this article is a certified Geobiological Consultant by the German Institut Geo-Baubiologie) makes us believe that this method gives very subjective results. Some claim that they measure geopathic fields with the use of geomagnetometers, however this measurement, especially indoors, detects static fields from steel pipe lines, reinforcement, bed springs and is not related to earthly energies.

Is there a meter that measures all types of radiation?

So far there are no meters that measure all types of radiation (ionizing and non ionizing), but there are meters that measure the basic artificial electromagnetic fields that are the main part of electrosmog today:

  • low frequency magnetic fields (non ionizing radiation from power lines, transformers etc)
  • low frequency electric fields (non ionizing radiation from electrical cables, devices, etc)
  • high frequency electromagnetic fields (non ionizing radiation from wireless phones, cell phones masts etc)

These are called combination meters and their main advantages is that you only need one to carry around for your basic emf measurements and they usually cost a lot less compared to buying 2-3 different meters to do the same measurements.

On the other hand combination meters tend not to perform well in all types of measurements.

Some times their performance in specific measurements is really terrible, so try to read their specifications and our comments in the comparison tables before you decide to buy one of them.

Read more about combination meters, their advantages and disadvantages..

Why should i measure the electromagnetic fields in my home or workplace?

The continuous increase of modern day electromagnetic pollution (=electrosmog) makes radiation measurements more relevant and necessary than ever, especially for the most vulnerable population groups (pregnant women, children, elderly and ill people).

Measurements of the invisible electromagnetic fields is the only way to determine if the areas where you spend most of your time exceed the proposed limits exposure to artificial radiation due to the presence of visible and invisible radiation sources (mobile phone masts, cordless telephones, and modem-router Wi- Fi, electrical appliances, cables, pylons, transformers etc.).

By measuring electromagnetic fields you can significantly reduce your daily electromagnetic burden, by identifying and avoiding electromagnetic hotspots and in many other ways which are detailed in the Home Biology EMF reduction guide.

“whereas electromagnetic fields (EMFs) exist in nature and have consequently always been present on earth; whereas, however, in recent decades, environmental exposure to man-made sources of EMFs has risen constantly, driven by demand for electricity, increasingly more specialised wireless technologies, and changes in the organisation of society; whereas the end effect is that every individual is now being exposed to a complex mixture of electric and magnetic fields of different frequencies, both at home and at work” European Parliament resolution on the health problems associated with electromagnetic fields (2008/2211) [1]

Are EMF measurements only needed when there is a significant radiation source nearby?

The high levels of radiation in a space is not only related to the proximity of visible external radiation source but also to the presence of radiation sources that you have no visible contact with or known sources that most people do not suspect as significant fields emitters.

For example wireless devices you or your neighbors use (such as cordless phones and Wi-Fi modems) often expose you to higher radiation values than neighboring cell phone masts due to shorter distance and indoor transmission.

Similarly, statistics indicate that the most common cause of elevated magnetic fields are the low voltage distribution cables that bring electricity to our homes and not the high voltage power transmission cables.

Other sources you should consider:

  • cell phone masts that are usually camouflaged as fake chimneys, solar panels, billboards, etc .. (cell phone masts are now in almost every neighborhood and their camouflage is a common practice of the telecommunication companies so as to avoid confrontations with neighbors)
  • amateur radio antennas, radio networks for police, taxis, logistic and security companies, radars in airports, ports, military, meteorological etc.
  • wireless devices from neighbors (cordless phones and modems, baby monitors, wireless alarms, cell phone signal amplifiers etc.)
  • underground power cables and transformers
  • ungrounded electrical appliances
  • electrical wiring issues (damaged insulation, errors in circuit connections etc)
  • radioactive building materials or radioactive radon gas leaking from cracks and pipes

Which population groups should definitely check their areas for high electromagnetic fields?

"We need to test the electromagnetic exposure of the sleeping location of the mother during pregnancy and also her working area, if she is working. If the mother is sleeping in strong electromagnetic fields the child will be neurologically abnormal. Within 2 years the child will develop all the signs of autism, neurological dysfunction, hyperactivity, learning disorders and so on." Dr. Dietrich Klingkchart, Institute of Neurobiology Washington [2]

  • For patients or those with unexplained health symptoms, because long-term exposure to a variety of artificial radiation is related to the development of wide range of health symptoms.

"Too often do we observe a marked concentration of particular illnesses in correspondingly high -frequency microwave radiation (HFMR) polluted areas or apartments. Too often does a long-term disease or affliction improve or disappear in a relatively short time after reduction or elimination of HFMR pollution in the patient's environment. Too often are our observations confirmed by on-site measurements of HFMR of unusual intensity." The Freiburger Appeal - Union Resolution of Environmental Medicine, Germany ( IGUMED) [3]

 

[1] European Parliament resolution of 2 April 2009 on health concerns associated with electromagnetic fields (2008/2211(INI))

[2] Dr. Dietrich Klinghardt, MD, PhD, Why the U.S. Needs Pre-Conception Healthcare, http://www.youtube.com/watch?v=sSit3i_-z0w

[3] www.laleva.cc/environment/freiburger_appeal.html

We advise you to read our guides on Low Frequency MetersHigh Frequency MetersCombination Meters and Radioactivity Meters which contain detailed information about how to use each type of meter and which are the important features to look for, but if you are in a hurry see all the recommended meters below:

When does your electromagnetic exposure exceed the recommended safety limits?

Why are the new safe exposure limits recommended by scientific bodies in recent years often exceeded in modern homes? Does the current legislation protect you?


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LEGAL EXPOSURE LIMITS

The legal exposure limits to non-ionizing electromagnetic radiation today are is most alligned with the limits set by the International Commission for the Protection against Non-Ionizing Radiation Protection (ICNIRP), which:

  • are "these guidelines are based on short-term, immediate health effects such as stimulation of peripheral nerves and muscles, shocks and burns caused by touching conducting objects, and elevated tissue temperatures resulting from absorption of energy during exposure to EMF." (exact quote from the ICNIRP guide [1])
  • recognize only the thermal effect of radiation and do not take into consideration other non thermal, effects such as the production of stress proteins, increased activity of free radicals, calcium outflow, increased permeability of blood-brain barrier, platelet aggregation, increased production of histamine etc.
  • have changed little in recent years, despite the rapid increase of electromagnetic pollution and the existense of new studies showing that these non-thermal action mechanisms can lead to long term health effects such as leukemia, breast cancer, brain and the acoustic nerve cancer, Alzheimer, insomnia, sexual dysfunction, depression, allergies, etc.
  • do not take into account the continuous and simultaneous exposure of the population to multiple radiation sources
  • ignore the increased absorption of radiation by infants and children
  • do not take into account the waveform of each radation emmition (digital vs analogue) shown to be a potent biological agent

The last point is particularly important because now most of the radiation we receive daily is due to the new type of wireless radiation from mobile phone masts, mobile phones, bases of wireless phones and wireless modems, which have digital waveforms with high intensity pulses.

In 2007, the Scientific Panel BioInitiative Working Group, which took into account more than 2000 studies on the effects of electromagnetic fields, concluded that:

"There is substantial scientific evidence that some modulated fields (pulsed or repeated signals) are bioactive, which increases the likelihood that they could have health impacts with chronic exposure even at very low exposure levels. Modulation signals may interfere with normal, non-linear biological processes. Modulation is a fundamental factor that should be taken into account in new public safety standards; at present it is not even a contributing factor. To properly evaluate the biological and health impacts of exposure to modulated RF (carrier waves), it is also essential to study the impact of the modulating signal (lower frequency fields or ELF-modulated RF). Current standards have ignored modulation as a factor in human health impacts, and thus are inadequate in the protection of the public in terms of chronic exposure to some forms of ELF-modulated RF signals. The current IEEE and ICNIRP standards are not sufficiently protective of public health with respect to chronic exposure to modulated fields (particularly new technologies that are pulse-modulated and heavily used in cellular telephony)."[2]

“The non-ionizing radiation protection standards recommended by international standards organizations, and supported by the World Health Organization, are inadequate. Existing guidelines are based on results from acute exposure studies and only thermal effects are considered. A world wide application of the Precautionary Principle is required. In addition, new standards should be developed to take various physiological conditions into consideration, e.g., pregnancy, newborns, children, and elderly people. “ The Venice Resolution Initiated by the International Commission for Electromagnetic Safety [3]

2

RECOMMENDED EXPOSURE LIMITS

In recent years many scientific bodies have proposed new exposure limits to protect the public from artificial electromagnetic fields, based on recent research showing that non-thermal radiation levels lead to serious long-term health effects.

LIMITS FOR HIGH FREQUENCY RADIATION

SCIENTIFIC BODY Proposed safety limit (power density and electric field)
in μW/m2 = uW/m2 (micro Watts per sq meter) in V/m (Volts per meter)
ICNIRP (International Commission for the Protection against Non-Ionizing Radiation Protection) 2000000-10000000 27-62
Seletun Scientific Panel (recommendations of international scientific panel) 170 0,25
European Parliament STOA (Science and Technology Options Assessment = Organization Valuation Sciences and Technologies of the European Parliament - recommendation of Dr. Hyland, Options Brief and Executive Summary, PE Nr. 297,574 March 2001) 100 0,2
German Building Biology Institue IBN (Institut für Baubiologie + Ökologie Neubeuern - Recommendations for the bedrooms) 10 0,06
BioInitiative Working Group (international team of scientists that reviews data from over 2000 studies on the effects of electromagnetic fields) 3-6 0,03-0,04
Austrian Medical Association 10 0,06
Radiation levels in nature <0,000001

<0,00001

The average population exposure indoors according to European surveys are below 100 microwatts / m2 (European Health Risk Assessment Network on Electromagnetic Fields Exposure, Report on the level of exposure in the European Union).

It should be noted that the recommended exposure limits tend to decrease, due to the accumulation of new reseach date, while the average exposure of the population tends to increase mainly due to the expansion of the cell phone grid and the higher use of wireless devices.

For example, the scientific group BioInitiative Working Group, which in our opinion is the most prestigious, now suggest a safety limit of 3-6 microwatts / m2 while in 2007 they proposed 100-1000 microwatts / m2.

Our view is that any epxosure values> 300 microwatts / m2 is quite high.

A realistic approach to those who want to limit their exposure to elevated (according to the proposed limits) wireless radiation values is to avoid places with values> 100 microwatts / m2 during the day and places with values> 10 microwatts / m2 in sleep areas.

What are high-frequency electromagnetic fields

  • High frequency radiation is generated by transmitters (antennas, etc.) used in wireless telecommunications, broadcast television signals, etc.
  • Their emission is usually continuous, and they may circulate freely in space at distances of a few meters to several kilometers.
  • Today it is hard to find areas unexposed to wireless radiation.
  • Many of the new wireless radiation typs are considered particularly aggravating because of their pulse waveform.

Common causes for exceeding 100 microwatts / m 2 (= microwatts per square meter)

  • cell phone masts (in most urban areas - usually camouflaged)
  • cordless phone or wi-fi internet antennas

LIMITS FOR LOW FREQUENCY RADIATION

SCIENTIFIC BODY Proposed safety limit (flux density)
in nT (nano Tesla) in mG (milli Gauss)
ICNIRP (International Commission for the Protection against Non-Ionizing Radiation Protection) 100000 1000
WHO = World Health Organization = World Health Organization (International Agency for Research on Cancer, a branch of the WHO has classified magnetic fields in the "possibly carcinogenic" based on studies that have linked 300-400nT with doubling the chance of childhood leukemia) 300-400 3-4
NCRP = National Council Of Radiation Protection and Measurement = National Council on Radiation Protection US (Non-validated scientific panel's recommendations NCRP - Scientific Committee 89-3 Report on Extremely Low Frequency Electric and Magnetic Fields) 200 2
TCO = Ecological Model for electronic devices (distance 30 cm) 200 2
argeTQ = green Austrian residential certificate 200 2
ÖKOPASS = residential certification, Austrian Institute of Biology Building (IBO) 100 1
Austrian Medical Association 100 1
German Building Biology Institue IBN (Institut für Baubiologie + Ökologie Neubeuern - Recommendations for the bedrooms) 100 1
BioInitiative Working Group (international team of scientists that reviews data from over 2000 studies on the effects of electromagnetic fields) 100 1
Levels in nature <0,0002 <0,000002

The 24-hour average exposure of the population is 70nT in Europe and 110nT in the US (World Health Organization, Electromagnetic fields and public health, Exposure to extremely low frequency fields).

Our view is that any values> 300 nT is quite high.

A realistic approach to those who want to limit their exposure to elevated (according to the proposed limits) magnetic field values is to avoid areas with values> 200 nT during the day and places with values> 100 nT during nighttime sleep.

What are the low-frequency magnetic fields

  • The non static magnetic fields are due to electrical current flow through electrical conductors (occur when there is power consumption)
  • It is important to identify the sources and the increase our distance from them. Magnetic fields penerate unaffected almost all buidling materials and elevated during hours with increased energy requirements.

Common causes for exceeding 200 nT (= nano = 10 -9 Tesla)

  • low voltage power diastibution cables
  • faulty electrical circuits connections
  • transformers in low voltage lighting

Electric field limits

SCIENTIFIC BODY Proposed safety limit (electric field strength and Body Voltage)
in V/m in mVolt
ICNIRP (International Commission for the Protection against Non-Ionizing Radiation Protection) 5000  
NCRP = National Council Of Radiation Protection and Measurement = National Council on Radiation Protection US (Non-validated scientific panel's recommendations NCRP - Scientific Committee 89-3 Report on Extremely Low Frequency Electric and Magnetic Fields) 10  
TCO = Ecological Model for electronic devices (distance 30 cm) 10  
argeTQ = green Austrian residential certificate 10  
ÖKOPASS = residential certification, Austrian Institute of Biology Building (IBO) 10  
Austrian Medical Association 1,5  
German Building Biology Institue IBN (Institut für Baubiologie + Ökologie Neubeuern - Recommendations for the bedrooms) 1,5 100
Levels in nature <0,0001

What are electric fields at low frequencies

  • The non static electric fields are caused by electrical voltage in live conductors.
  • They are continuously emitted in every electrified area.
  • The presence of high electrical fields especially in the bedrooms should be avoided, since they might undermine the process of cell revitalization during the night sleep.
  • There are many simple solutions to avoid them.

Common causes of exceeding 10 V / m (= volts per meter)

  • Deficient grounding or errors in insulation of electrical wiring in the walls
  • Ungrounded electrical appliances

“The key point about electromagnetic pollution that the public has to realize is that it is not necessary that the intensity be large for a biological interaction to occur. There is now considerable evidence that extremely weak signals can have physiological consequences. These interactive intensities are about 1000 times smaller than the threshold values formerly estimated by otherwise knowledgeable theoreticians, who, in their vainglorious approach to science, rejected all evidence to the contrary as inconsistent with their magnificent calculations. These faulty estimated thresholds are yet to be corrected by both regulators and the media.”Abraham Liboff, researcher, Center of Molecular Biology and Biotechnology, University of Florida Atlantic [4]

 

[1] ICNIRP Guidelines For Limiting Exposure The Time-Varying Electric, Magnetic, And Electromagnetic Fields

[2] http://www.bioinitiative.org

[3] http://www.icems.eu/resolution.htm

[4] Camilla Rees- Magda Havas, Public Health SOS - The Shadow Side of the Wireless Revolution

How to measure high frequency (wireless) radiation + RF meters comparison guide

How to easily measure radiation from cell phone masts, Wi-Fi etc. How to choose an economical, reliable and easy to use high frequency radiation meter. Which are the necessary features. How to use the meter to spot radiation sources and reduce your radiation exposure.


wireless

Not the type of meter you are looking for? Please check our guides on low frequency meters (measure radiation from power lines, cables, transformers, electric devices laptops etc), radioactivity meters (measure radiation from radon gas, granite counters, nuclear accidents etc) or check the frequently asked questions about electromagnetic field meters!

We advise you to read all the following information about how to use a high frequency meter and which are the important features to look for, but if you are in a hurry to see the recommended meters go straight to the high frequency meters comparison tables at the end of the article.

What do high frequency meters measure?

They measure electromagnetic fields (radio waves, micro waves etc) from cordless phones, wireless modems (Wi-Fi), cell phone masts, mobile phones, baby monitors, wireless laptops, smartphones, printers, keyboards, speakers, game consoles, Bluetooth devices, microwave ovens, wireless alarm, fire detection and temperature control systems, radars, TV and radio antennas (depending on their frequency range).

Were do we usually record high wireless radiation levels?

  • In houses close to cell phone or broadcast towers (most burdened areas are those that have windows facing the antennas)
  • In apartments and offices were a multitude of wireless signal from Wi-Fi, cordless phones etc is recorded devices from neighbors
  • In densely populated areas because of the presence of more cell phone masts
  • On the upper floors of buildings because they are more exposed to wireless radiation from all high frequency sources
  • Laboratories, diagnostic centers, recording studios, etc should also check for high frequency radiation levels, because they have electronic equipment that is sensitive to electromagnetic interference

How to use the high frequency meters

  • Measure close to the walls, the ceiling and the floor adjacent to neighboring apartments, so you can locate the wireless devices of your neighbors (eg cordless telephones, Wi-Fi Internet modem-routers, DECT phones etc), which will probably produce higher radiation values in certain areas of your premises.
  • This way you can avoid the electromagnetic hotspots you detect or ask your neighbor to move his wireless devices to another location.
  • You can also use shielding materials (eg use a shielding fabric over a couch or bed when you identify a strong signal from below, use shielded bed canopies, paint the walls with EMF shielding paints etc.).
  • If you detect cordless phones you can ask your neighbor to replace it with a low-radiation cordless telephone whose base emits only time when you talk to the phone and not on stand by mode.
  • Also, measure the radiation close to the windows and walls that are facing outdoor areas to check if you have significant radiation from the outside (i.e. cell phone masts).
  • If there is an obvious or hidden cell phone mast nearby you will record higher radiation levels close to external walls or windows in the mast’s direction.
  • Windows are the most vulnerable point of penetration because they do not reflect high frequency radiation (unless they have reflective or mirrored or low-e glass, which is coated with metal oxides for thermal insulation purposes). Windows can be easily shielded using EMF shielding curtains or window films, which reflect more than 99% of wireless radiation.
  • Walls reflect/absorb part of the external wireless radiation depending on the thickness and type . Walls and roofs can be shielded by painting with an EMF shielding paint.

See more ways to reduce your radiation exposure…

More tips about using high frequency meters

  • High frequency electromagnetic waves are either vertical or horizontally polarized. Try to rotate the meter in all directions when measuring in a certain area.
  • Indoor measurements might vary significantly from point to point mainly to reflections in the furniture, appliances and building materials.
  • Metallic objects might amplify the high frequency fields, creating local radiation hotspots.
  • Try to take multiple measurements at different times during the day and during the year. Cell phone masts vary their transmission power depending on the demand and every year some kind of new signal (3G, 4G etc) gets added to their transmission. Also, regular maintenance works on cell phone mast might slightly change the transmission angle, which could lead in great difference of radiation levels. In addition, you might locate a Wi-Fi modem or other WI-Fi enabled device that works only during certain hours of the day. Finally, your neighbours might purchase a new wireless device or other outdoor antennas might be added any minute changing dramatically your EMF exposure. This is why you have to check regularly.
  • Most of the high frequency meters are reliable for “far field” measurements (roughly more than 3 times their wavelength in meters) which means that you can take wrong measurements when you really close to the radiation source, which is closer than 1 meter for most modern radiation sources (cell phones, WiFi, DECT etc)
  • Do not cover the antenna with your hands or other objects when measuring.
  • You might notice excessive radiation values when moving the meter quickly. Try to make slow and steady movements.
  • Hold the meter at arm’s length.

What features to look for in an RF meter

Manufacturer

A reputable company or country of manufacture could mean better quality and extended operating life. Being more geographically close might be helpful if there is a malfunction of the meter or you need to send it back for recalibration.

Average price

This is the average price of the meter sold by the various online sellers shown on the bottom of each table.

Antenna/Sensor

High frequency meters are characterized as single axis, triple axis, omnidirectional, isotropic, directional etc according to the type of antenna/sensor they have.

In high frequency measurements most meters measure in 1 axis, which means you have to turn the meter in all directions to approximately calculate the total (3 axis) radiation.

Some meters have a directional (logarithmic) antenna (see on the photo to your right the antenna used by Gigahertz meters). These meters are also single axis but the directional antenna helps you find the direction of radiation penetration so you can easily locate the radiation source.

Some meters offer 3 axis measurements which means they use three single axis antennae to compute the overall exposure.

Some have omni-directional antenna which provides a 360 degree horizontal radiation coverage.

An isotropic antenna is a theoretical antenna that has a 360 degree vertical and horizontal coverage, so meters that claim they have isotropic antennas, should give the most accurate measurements. In real life when they say isotropic they usually mean omnidirectional.

Both 3 axis and omnidirectional antennas help you perform quicker and more accurate measurements but help less in locating the source compared to directional antennas.

To conclude, single axis antennas are the poorest choice, directional antennas are better for locating radiation sources and a 3 axis or an omnidirectional or an isotropic antenna will give you more accurate measurements. Combining directional and an omnidirectional antenna (as the HF35EC does) combines all the benefits.

Frequency range (MHz)

Each wireless radiation source emits in a certain frequency (the number of oscillations or wave cycles that pass a particular point per second). The higher the frequency, the higher the energy and the shorter the wavelength of the wave (frequency=speed of light/wavelength).

Frequency units used are Hz (Hertz) and Khz=1000Hz, MHz = 1000000Hz and GHz = 1000000000Hz

High frequency meters should be able to record radiation at least in the 800MHz-2500Mhz frequency range, were most modern radiation sources (cell phone masts, smaprtphones, Wi-Fi etc) emit.

If you are interested in measuring TV or Radio broadcast signals you should choose a meter that measures down to 100MHz or below.

If you interested in measuring radar signals you should choose a meter that measures above 3000MHz, but for many reasons we do not think it is necessary:

  • a meter that measures in a wide frequency range will probably detect more sources but it usually provides less accurate measurements and makes it also more difficult to figure out where the radiation comes from
  • test show that many meters which claim to measure up to 8GHz cannot often detect or measure most higher frequency sources, so they are useless (see more information below).
  • wireless sources above 3GHz are still relatively rare, so you probably do not really measure higher frequencies

Here is a table list of the most common radiation sources and the frequencies they usually emit (might differ from country to country):

Source frequency range Mhz
ΑΜ RADIO 0,4-1,5
FM RADIO 87-108
VHF TV 40-230
TETRA 380-400
DVB-T 470-600
UHF TV 400-900
Baby monitors 49 , 900, 2400
Cell phones and cell phone masts 900,1800,2100
DECT (cordless phones) 1800-1900
(5700-5800 DECT2)
WLAN (Wi-Fi) modems, tablets etc 2400-2500
(5100-5800 WLAN2)
Bluetooth 2400-2500
Microwave ovens 2400-2500
Radars 3000-40000

Units of measurement

High frequency radiation meters measure electromagnetic field power density (in mW/m2 = milliwatts per square meter = 1000 μW/m2 = 1000 uW/m2 = 1000 microwatts per square meter or W/cm², or W/m²) or high frequency electric field intensity (in V/m = Volts per meter), or both.

Some meters also measure magnetic field strength in A/m (ampere per meter) or μA/m, mA /m but this not really needed.

Some meters meausure in dBm, the power ratio in decibels (dB) of the measured power referenced to one mill watt (mW). It is a convenient measure of absolute power because of its capability to express both very large and very small values in a short form. But for most non technical users who just want to check their area for common wireless radiation sources, dBm is only confusing. The same goes for dBW, which is referenced to one watt (=1000 mW).

Units can be converted from one to the other:

V / m = SQRT [(μW/m2) * 0,000377]

and

μW/m2 ={[(V/m)^2)]/377}*10^6

These conversions are not valid very close to the radiation sources (near field measurements = roughly less than 3 times their wavelength in meters). The near field is less than 2 meters for most modern radiation sources (cell phones, WiFi, DECT etc) For example a Wi-Fi modem transmitting at 2400MHz has a wavelength λ=c/f (were c= 299792458 and f= 2400000000Hz) = 0,12m which means far field is >3*0,12 =0,36m.

You find ready unit conversion calculators here:

For easier comparison to the recommended radiation limits we prefer the meters that measure in μW/m2 (=uW/m2) or V/m

Measurement range

The high frequency meter should be able measure values as low as 1 μW/m2 (=0,02 V/m) so you can compare them to even the lowest recommend safety limits.

Being able to measure up to millions of μW/m2 (were usually the legal limits are) would be great but not necessary, as most common radiation sources emit up to a few thousands of μW/m2.

Some meters have signal attenuators, or preamplifiers so that they can extend their measurement range.

There are also meters that don’t give an exact measurement but only a measurement range and usually have some warning lights depending on the radiation levels. If you don’t care about the exact radiation levels but only to get a warning for high radiation levels this could helpful.

The measurement span is something that many people don’t pay too much attention and they end up buying a meter that cannot measure what they need. This is especially true for many meters that supposedly measure all types of radiation, but in reality they only detect very high power sources. For example the famous Trifield Meter 100XE could only measure very high levels of high frequency radiation, meaning it cannot detect most common wireless radiation sources. Unlike the Trifield 100XE, the new Trifield TF2 has good sensitivity and measurement range.

What are the safe levels of high frequency radiation?

The legal exposure limits to non-ionizing electromagnetic radiation today are in most countries aligned with the limits set by the International Commission for the Protection against Non-Ionizing Radiation Protection (ICNIRP), which recognize only the thermal effect of radiation and do not take into consideration other non thermal, effects such as the production of stress proteins, increased activity of free radicals, calcium outflow, increased permeability of blood-brain barrier, platelet aggregation, increased production of histamine etc.

The past few years many scientific bodies have proposed new exposure limits to protect the public from artificial electromagnetic fields, based on recent research showing that non-thermal radiation levels can lead to serious long-term health effects.

The differences in the proposed safe limits are quite remarkable as you can see on the table below:

SCIENTIFIC BODY Proposed safety limit
in μW/m2 = uW/m2 in V/m
ICNIRP (International Commission for the Protection against Non-Ionizing Radiation Protection) 2000000-10000000 27-62
Seletun Scientific Panel (recommendations of international scientific panel) 170 0,25
European Parliament STOA (Science and Technology Options Assessment = Organization Valuation Sciences and Technologies of the European Parliament - recommendation of Dr. Hyland, Options Brief and Executive Summary, PE Nr. 297,574 March 2001) 100 0,2
German Building Biology Institue IBN (Institut für Baubiologie + Ökologie Neubeuern - Recommendations for the bedrooms) 10 0,06
BioInitiative Working Group (international team of scientists that reviews data from over 2000 studies on the effects of electromagnetic fields) 3-6 0,03-0,04
Austrian Medical Association 10 0,06
Radiation levels in nature <0,000001

<0,00001

Generally, the recommended exposure limits are below 200 microwatts / m2 (=0,27V/m).

The average population exposure indoors from all high frequency sources according to European surveys were below 100 microwatts / m2 in Europe until 2010 (European Health Risk Assessment Network on Electromagnetic Fields Exposure, Report on the level of exposure in the European Union).

Our opinion is that values> 500 microwatts / m2 (0,43 V/m) are high.

Ideally we recommend that you record values <100 μ/m2 in all areas and <10 μW/m2 in your bedroom.

Detailed information about the proposed and permitted levels can be found in our article "Safe Exposure Limits' .

Signal

Most international safety standards take into account the Average radiation power (RMS = root mean square = the square root of the arithmetic mean of the squares of the samples), usually measured over a period of 6 minutes.

On the other hand Building Biologists or scientists that recommend lower precautionary safety limits, claim that the important measurement for high frequency radiation is the Peak signal radiation levels.

This is especially important for digital signals (Wi-Fi, cell phone masts, DECT etc) which have a pulsed waveform (a lot of time they are not transmitting) and so the average power is many times lower than the peak power. This for many scientists underestimates the radiations levels compared to their the biological effects.

For older analogue or continuous wave signals, average and peak levels are similar.

Peak hold measurement means the meter retains the highest readings, so you can easily measure the highest radiation value in a given area.

Some meters also distinguish between pulsed and non pulsed radiation levels, giving another way of determining the safety of your area. Also the German Building Biology Institute recommends much lower safety limits for pulsed radiation (they consider extreme levels >100μW/m2 for pulsed and >1000 μW/m2 for all signals).

The BioInitiative Report concludes that:

"There is substantial scientific evidence that some modulated fields (pulsed or repeated signals) are bioactive, which increases the likelihood that they could have health impacts with chronic exposure even at very low exposure levels.

Modulation signals may interfere with normal, non-linear biological processes.Modulation is a fundamental factor that should be taken into account in new public safety standards; at present it is not even a contributing factor. To properly evaluate the biological and health impacts of exposure to modulated RF (carrier waves), it is also essential to study the impact of the modulating signal (lower frequency fields or ELF-modulated RF).

Current standards have ignored modulation as a factor in human health impacts, and thus are inadequate in the protection of the public in terms of chronic exposure to some forms of ELF-modulated RF signals. The current IEEE and ICNIRP standards are not sufficiently protective of public health with respect to chronic exposure to modulated fields (particularly new technologies that are pulse-modulated and heavily used in cellular telephony).”

So Peak signal measurements are more important biologically but if you do official measurements you will also need to measure average value and also have a meter that records data.

Data logging

Data logging is more important in low frequency magnetic field measurements. For high frequency measurements it is useful if you want to measure following most official measurement guidelines that measure the average radiation over a period of a few minutes.

Display

A digital display gives you more accurate readings and has a more modern and professional look. Analogue displays are rather outdated, but are usually cheaper and will also do the job.

Backlight display

Not a necessary feature but is helpful when measuring in dark areas or in houses with no working lights.

Audio signal

Audio signal which increases volume according to the radiation value, is helpful but even more helpful is the acoustic demodulation of the wireless signals, that some meters offer.

Audio signal demodulation means the meter will make a different sound according to the radiation source. This feature is a must when you want to identify what kind of device or antenna is to blame for your elevated radiation levels!

See in the video how to locate cell towers in the area, cordless phones and modem-routers of your neighbors and other wireless devices using a meter with audio signal and a directional antenna!

Audio alarm

Audio alarm is helpful for finding radiation hotspots but not necessary when you have audio signal. Some meters also allow to set the alarm threshold yourself.

Accuracy

Higher accuracy is good but it is more important for professional users and not for amateurs. Also, manufacturers show their accuracy data in various ways, making it difficult to distinguish the ones with crappy accuracy.

Due to the nature of high frequency waves propagation the accuracy of high frequency meters is not very high and it is also difficult to reproduce measurements especially in indoor areas. Most manufacturers mention accuracy in dB (decibels) and not in percentages. For example, an ordinary amateur meter accuracy is +/-6dB which translates to -75% to + 200%. Commercial grade models might have a + -3dB accuracy which translates to -50% to + 100%.

The Electric Power Research Institute in its 5000$ report “Consumer-Grade Radio-Frequency (RF) Exposure Meters” sates that:

“Because of differences in design, reliability, and functionality, direct comparisons of meters is difficult, especially because meters are designed for so many different applications.

One common function of all the meters is to detect the presence of an RF field, but some meters provide little more information than that. Some meters are not able to detect RF fields below a set field strength while others are tuned to a certain frequency range.

Consumers need to recognize that each meter’s performance can vary dramatically at different frequencies, distances, and orientation. Such variations can be significant and may limit interpretation of measurement results."

The most important to have in mind is that some some tests show that the accuracy is often not what is claimed by the manufacturers.

So choosing more accurate meters could be more helpful in theory than in practice.

Batteries and battery life

If you plan to use the meter a lot then you should definitely take into account the battery type and life of the batteries used, because changing batteries frequently could elevate the operating cost significantly. Some meters are rechargeable so you don’t have to purchase new batteries every little while.

Low battery indication

Warns you about low battery so it helps you not run out of batteries unexpectantly.

Auto power off

Helps you avoid battery loss when you accidentally forget the meter on.

Carrying case

A good quality plastic case is very helpful for professionals or for those those who frequently measurements in various locations.

Calibration service

If you need to check that everything works well in the future you might consider sending it for calibration (or recalibration if the meter was originally calibrated). This is especially important for professional users. In that case you should choose a manufacturer that offers this service. Also it would be better if the manufacturer is geographically close to you.

Warranty

The longer the warranty the better, especially if the meter is expensive.

Seller

We try to we recommend reputable companies, with good customer service, that can ship the meters worldwide.

Being more geographically close might be helpful if there is a malfunction of the meter, so we usually recommend one seller from the USA and one from Europe.

Also, buying from an overseas company means there will be some extra shipping costs and possible tax charges in the customs office.

Finally, please be sure to check all the mentioned features (warranty, prices etc) also in the sellers page, because they could be different from those mentioned in the following comparison tables or have changed since the time this article was written.

Some tips for professional users

  • There are meters in the market that are targeting professional users and are priced very high, though they seemingly offer the same features.
  • Some times, the increased price is justified by some extra features such as frequency analyzing, higher accuracy, data logging capability etc. Make sure you really need those features before you spend extra money on them.
  • On the other hand, more expensive meters usually also mean higher overall quality, more professional design, longer and more reliable operation, longer warranty, better service and the potential to get your meter recalibrated, which are important for professional users.
  • And your clients will value your service more if you use a high end meter, rather than a cheap one.
  • We suggest you try to avoid all in one combination meters. They do not perform well in all types of measurements.
  • Also, using more meters will make a better impression to your clients, than doing all the measurements with only one meter.
  • While smaller and lighter meters are easier to transport, bigger and heavier meters look and feel more professional.

Basic high frequency meters

The basic low cost meters presented below will measure correctly most common high frequency radiation sources but not with great accuracy, might not detect all the frequencies claimed by their manufacturer or have the expected sensitivity.

Since they are low cost they have their place in the market, but do not expect them to perform as professional meters.

Some manufacturers, have no problem admitting their meters limitations. As Cornet (USA) admits in one of their manuals “(our meter) is designed for quick living environment RF radiation evaluation and is for reference use only. Official RF safety radiation measurement procedure is complicate and should be handled by trained technical person with lab instruments”.

The German Consumer Protection Organization (WILA Bonn) commissioned IMST GmbH (an accredited EMC testing facility in Germany) to test low cost meters that could measure up to 8GHz.

The results showed that all meters performed poorly in frequencies above 3GHz which means that the advertised very wide frequency range is not valid.

Also the claimed sensitivity of the meters was not as promised. In most cases they could not measure values lower than 10μW/m2 which are recommended by the Building Biology Institute and BioInitiative Working Group.

The German report “Electrosmog meters put to the test” concludes that:

“It is good to maintain a healthy skepticism toward offers that promise amazing performance at extremely favorable prices.

And it is always good to remember that professional testing equipment never combines RF and ELF measurement probes in one single meter or fits an RF antenna into the meter casing.

Antennas/probes that are integrated into the meter casing are also a great source of errors.

Prefer meters with a digital display and an external measurement antenna. A highly directional logarithmic-periodic antenna (which looks like a Christmas tree or fish skeleton) is very useful in determining the direction from where the RF radiation originates."

So to conclude all of the basic high frequency meters below have their limitations (we try to highlight them in the following tables).

Their main advantages are their low price and their basic functions.

Also, due to the fact that their antenna is inside the meters case, most of them have a very small size. Smaller and lighter meters are easier to transport. They are also great when you want to take measurements discreetly.

And if you don’t see a low cost frequency meters in the following tables, it is most likely that we have rejected it because it does not fill some basic criteria (frequency range, measurement span etc).

For professional use or for more accurate and reliable measurement you should invest in other type and/or more expensive meters (see advanced meters below).

Advanced high frequency meters

METRITES SMALL (2)A company that provides reliable, even low cost, meters for professional and amateur users is Gigahertz Solutions (Germany).

All of their high frequency meters have a directional antenna (logarithmic – periodic) that helps you locate the radiation sources.

Some of Gigahertz meters provide a second antenna which is isotropic (meaning it receives radiation from all directions), making measurements more accurate and expanding their frequency range.

Most of their meters also have audio signal which is different according to the radiation source, so they help us identify which is the problematic radiation source.

And all their products features completely concur with the information supplied on the corresponding data sheets which unfortunately is not valid for many low cost high frequency meters.

Building biology's associations worldwide recommend Gigahertz equipment for the easy evaluation or professional analysis of EMF / RF pollution.

All meters developed and produced by Gigahertz are manually aligned and calibrated during the manufacturing process and the VDE (the German Association for Electrical, Electronic and Information Technology) monitors their quality control system with annual inspections.

Finally, we have personally used Gigahertz meters in hundreds of EMF surveys and know from first hand that they are very easy to use, sturdy, reliable and accurate.

Also, Gigahertz has great customer care and offers calibration services!

Want to measure more types of electromagnetic fields? The only combination meter that seems to perform well in the 3 basic measurements (low frequency electric and magnetic, high frequency electromagnetic) is the new Trifield TF2 meter. See or combination meters article for more information. Again, for high frequency measurements we recommend that you purchase a meter with directional antenna and a different audio signal according to the radiation source (like most Gigahertz meters).

How to measure low frequency radiation + Gauss meters comparison guide

How to easily measure radiation from high-voltage power lines, cables, transformers, electric devices laptops etc. How to choose an economical, reliable and easy to use low frequency radiation meter. Which are the necessary features. How to use the meter to spot radiation sources and reduce your radiation exposure.


lowfrequencysources 

Not the type of meter you are looking for? Please check our guides on high frequency meters (measure radiation from from cordless phones, wireless modems (Wi-Fi), cell phone masts etc), radioactivity meters (measure radiation from radon gas, granite counters, nuclear accidents etc) or check the frequently asked questions about electromagnetic field meters!

We advise you to read all the following information about how to use a low frequency meter and which are the important features to look for, but if you are in a hurry to see the recommended meters go straight to the low frequency meters comparison tables at the end of the article.

What do low frequency meters measure?

Low frequency radiation meters measure magnetic and / or electric fields from all wired radiation sources (power lines, cables, electrical appliances etc).

All cables, devices and other conductors that are connected to the power network generate electrical alternative current (AC) fields due to electrical voltage. When electrical current flows through the conductors (when there is electricity consumption) AC magnetic fields are also produced.

So, when an electric appliance is plugged in the electrical socket, an electric field is created due to voltage. When the device in turned on a magnetic field is produced due to electrical current flow.

Electric fields from power lines, transformers etc do not penetrate interior areas because they are grounded by most building materials (except near glass or in wooden houses).

Magnetic fields on the other hand penetrate all areas since they are unaffected by most building materials.

Which are the main sources of magnetic fields?

  • high voltage power transmission cables (the cables are the source - not the pillars)
  • low and medium voltage power distribution cables (low voltage wires are the main cause of high magnetic fields)
  • power transformers electrical meter and
  • electrical panels
  • large consumer appliances such as kitchen, electric heaters, floor heating, boilers, etc.
  • low voltage devices operating with a power transformer such as low voltage lighting and lamps, phone chargers, electric clocks, laptops etc.
  • appliances with electric motors such as the refrigerator, blender, vacuum cleaner, air fans, hair dryers, etc.
  • televisions and computer screens (the older type CRT)
  • wiring errors (such as neutral conductor connections from different circuits)
  • leakage currents on the electrical ground and earthed metallic parts (e.g. water pipes, heating pipes)
  • asymmetric charge distribution in a three phase power system
  • underfloor heating (with electrical resistance wires instead of plastic water tubing).
  • alternators for photovoltaic systems

Measuring magnetic fields is, in our opinion, the most important radiation measurement in order to assess the electromagnetic burden of a building, especially before buying a property, since high values of magnetic fields are usually difficult and expensive to reduce.

Which are the main sources of electric fields?

  • all electrical appliances when they are not connected to the electrical ground (depends on the plug – bipolar ones do not ground the appliance as opposed to schuko plugs)
  • the cables are in the walls that power electrical outlets, sockets and lights (especially when there are not grounded or the grounding is not functional, or the electrical connections are faulty or the cables insulation is damaged).
  • high voltage power lines cables (usually only outdoors - except near glass or in wooden houses)

Low frequency electric field measurements in our opinion are most relevant in areas such as bedrooms, where the continuous power supply of devices and circuits is not necessary and there are many simple ways to reduce it. Additionally, many scientists believe the presence of high electric fields considered more burdensome during night sleep.

How to measure low frequency fields + Solutions

If you are using a triple axis meter (recommended) just turn it on and measure.

If you are using a single axis meter rotate it to all directions and see the highest reading (rough estimate of the total radiation).

By measuring you can detect the radiation sources and remove them or replace them or increase your distance from them.

Magnetic fields can be shielded but magnetic shielding materials are very expensive and not always helpful.

Electric fields can be shielded more easy by using conductive materials that are grounded: from trees to conductive paints and meshes.

See more ways to reduce your radiation exposure…

What features to look for in a low frequeny magnetic and/or electric field meter

Manufacturer

A reputable company or country of manufacture could mean better quality and extended operating life. Being more geographically close might be helpful if there is a malfunction of the meter or you need to send it back for recalibration.

Average price

This is the average price of the meter sold by the various online sellers shown on the bottom of each table.

Antenna/Sensor

Meters with a single axis or 1D sensor can measure only in one direction at a time, so in order to measure the total radiation you will need to measure separately in each of the three axes by rotating the meter accordingly and then calculate the vector sum or find the axis with the maximum value to roughly find the total value.

3-axis meters on the other hand calculate directly the total three-dimensional value. A 3-axis meter is much easier to use and helps you perform quicker and more accurate measurements.

Frequency range (MHz)

The main frequency range that interests us is the 50-60Hz (frequency of the power grid) and covering this frequency range should be enough for most users.

Electronic devices with non linear loads (inverter AC, fluorescent lights etc) may emit in frequencies in the 20000-40000Hz range. Measuring up to this range might elevate the measured values a bit, but will also take into account the dirty electricity phenomenon, caused by harmonics.

Being able to distinguish between measurements in the 50-60Hz range and in higher frequencies is an additional feature some meters offer.

Units of measurement

Magnetic field meters measure magnetic flux density (B) in nT (= nano Tesla = 0,000000001 Tesla) or μΤ = uT (= micro Tesla = 0,000001 Tesla) or mG (= milli Gauss = 0,001Gauss). So 100nT=1mG

Electric field meters measure electric field intensity (E) in V / m (= volts per meter).

An alternative and interesting way of measuring the electric field is by measuring Body Voltage in milliVolts (= mV = 0,001 Volt). We connect a multimeter with the electrical ground and our body and record the alternating voltage developed through capacitive coupling of the human body with the surrounding electric fields.

Measurement range

We should take into account the lowest recommend safety limits and also the electromagnetic fields emitted by the most common radiation sources:

Magnetic field meters should be able to record in the 50-2000nT (0,5-20mG) range. Higher levels might be recorded in the very close vicinity (<0,5 m) to certain transformers, motors etc.

Electric field meters should be able to record in the 1-200V/m range.

What are the safe levels of low frequency radiation?

The legal exposure limits to non-ionizing electromagnetic radiation today are in most countries aligned with the limits set by the International Commission for the Protection against Non-Ionizing Radiation Protection (ICNIRP), which recognize only the thermal effect of radiation and do not take into consideration other non thermal, effects such as the production of stress proteins, increased activity of free radicals, calcium outflow, increased permeability of blood-brain barrier, platelet aggregation, increased production of histamine etc.

The past few years many scientific bodies have proposed new exposure limits to protect the public from artificial electromagnetic fields, based on recent research showing that non-thermal radiation levels can lead to serious long-term health effects.

The differences in the proposed safe limits are quite remarkable as you can see on the table below:

MAGNETIC FIELDS
SCIENTIFIC BODY Proposed safety limit
in nT in mG 
ICNIRP (International Commission for the Protection against Non-Ionizing Radiation Protection) 100000 1000
WHO = World Health Organization = World Health Organization (International Agency for Research on Cancer, a branch of the WHO has classified magnetic fields in the "possibly carcinogenic" based on studies that have linked 300-400nT with doubling the chance of childhood leukemia) 300-400 3-4
NCRP = National Council Of Radiation Protection and Measurement = National Council on Radiation Protection US (Non-validated scientific panel's recommendations NCRP - Scientific Committee 89-3 Report on Extremely Low Frequency Electric and Magnetic Fields) 200 2
TCO = Ecological Model for electronic devices (distance 30 cm) 200 2
argeTQ = green Austrian residential certificate 200 2
ÖKOPASS = residential certification, Austrian Institute of Biology Building (IBO) 100 1
Austrian Medical Association 100 1
German Building Biology Institue IBN (Institut für Baubiologie + Ökologie Neubeuern - Recommendations for the bedrooms) 100 1
BioInitiative Working Group (international team of scientists that reviews data from over 2000 studies on the effects of electromagnetic fields) 100 1
Levels in nature <0,0002 <0,000002
ELECTRIC FIELDS
SCIENTIFIC BODY Proposed safety limit
in V/m in mVolt
ICNIRP (International Commission for the Protection against Non-Ionizing Radiation Protection) 5000  
NCRP = National Council Of Radiation Protection and Measurement = National Council on Radiation Protection US (Non-validated scientific panel's recommendations NCRP - Scientific Committee 89-3 Report on Extremely Low Frequency Electric and Magnetic Fields) 10  
TCO = Ecological Model for electronic devices (distance 30 cm) 10  
argeTQ = green Austrian residential certificate 10  
ÖKOPASS = residential certification, Austrian Institute of Biology Building (IBO) 10  
Austrian Medical Association 1,5  
German Building Biology Institue IBN (Institut für Baubiologie + Ökologie Neubeuern - Recommendations for the bedrooms) 1,5 100
Levels in nature <0,0001

Generally, the recommended exposure limits are below 200 nT (=2mG) for magnetic fields and below 10 V/m for electric fields.

The average exposure of the population is 70nT (= 0,7mG) in Europe and 110nT (=1,1mG) in the US (World Health Organization, Electromagnetic fields and public health, Exposure to extremely low frequency fields).

Our opinion is that any values> 300 nT and >50V/m are quite high.

Ideally we should record values <200 nT and <10 in all areas and <100nT and <2V/m in bedrooms at night.

Detailed information about the proposed and permitted levels can be found in our article "Safe Exposure Limits' .

Signal

Some meters dont explain what exactly they measure so they either mean the instant or average value.

Many meters measure the RMS value (= root mean square = the square root of the arithmetic mean of the squares of the samples) meaning the average.

Meters that measure “true RMS” give more accurate readings than those that measure simple RMS.

Peak and peak hold measurements are not so important for low frequency fields.

Data logging

This feature is very helpful for magnetic field measurements (not for electric field measurements) which vary greatly in time, due to the electrical load fluctuation on the power lines.

For example when measuring magnetic fields near a low voltage power line you might record 1mG in one minute and 3mG after a few seconds.

A meter that records and stores data at least for 24 hours helps you calculate your exposure more accurately and compare it to the safety limits which refer to 24 hour average exposure.

Some meters also offer a data logging PC software that helps you see which hours of the day have the highest magnetic fields and other statistical values.

Display

A digital display gives you more accurate readings and has a more modern and professional look. Analogue displays are rather outdated, but are usually cheaper and will also do the job.

Backlight display

Not a necessary feature but is helpful when measuring in dark areas or in houses with no working lights.

Audio signal

Having audio signal which increases volume according to the radiation value, is helpful for finding radiation hotspots but is not necessary in our opinion for low frequency meters (it is more useful for high frequency meters).

Audio alarm

Audio alarm is helpful for finding radiation hotspots but not necessary when you have audio signal. Some meters also allow you to set the alarm threshold.

Accuracy

Higher accuracy is good but it is more important for professional users and not for amateurs. Also, manufacturers show their accuracy data in various ways, making it difficult to distinguish the ones with crappy accuracy.

Batteries and battery life

If you plan to use the meter a lot then you should definitely take into account the battery type and life of the batteries used, because changing batteries frequently could elevate the operating cost significantly. Some meters are rechargeable so you don’t have to purchase new batteries every little while.

Low battery indication

Warns you about low battery so it helps you not run out of batteries unexpectantly.

Auto power off

Helps you avoid battery loss when you accidentally forget the meter on.

Carrying case

A good quality plastic case is very helpful for professionals or for those who frequently measurements in various locations.

Calibration service

If you need to check that everything works well in the future you might consider sending it for calibration (or recalibration if the meter was originally calibrated). This is especially important for professional users. In that case you should choose a manufacturer that offers this service. Also it would be better if the manufacturer is geographically close to you.

Warranty

The longer the warranty the better, especially if the meter is expensive.

Seller

We try to we recommend reputable companies, with good customer service, that can ship the meters worldwide.

Being more geographically close might be helpful if there is a malfunction of the meter, so we usually recommend one seller from the USA and one from Europe.

Also, buying from an overseas company means there will be some extra shipping costs and possible tax charges in the customs office.

Finally, please be sure to check all the mentioned features (warranty, prices etc) also in the sellers page, because they could be different from those mentioned in the following comparison tables or have changed since the time this article was written.

Are magnetic field measurements more important than electric field measurements?

  • Low frequency magnetic fields have been listed as “possible carcinogens” by the IARC (WHO), unlike low frequency electric fields.
  • Magnetic fields penetrate all areas since they are unaffected by most building materials, while electric fields from power lines, transformers etc do not penetrate interior areas because they are grounded by most building materials.
  • While you can make a good guess about the levels of electric fields in an indoor area (high values usually only near electrical devices which are not grounded), it is difficult to estimate magnetic fields of seemingly similar radiation sources. Also, the sources of magnetic fields vary greatly and are much more often not visible.
  • High values of magnetic fields are usually difficult and expensive to reduce, so it is much more important to measure them especially before buying a new property, while electric fields are much easier to reduce.
  • While it is easy and affordable to perform accurate 3-D magnetic field measurements (triple axis magnetic field meters come with a reasonable price) the majority of electric field meters are only single axis, so are more difficult to use and triple axis electric field meters are few and very pricey.

What are the main categories of magnetic field meters?

The main feature that distinguishes magnetic field meters is whether they have a single axis or 1D sensor or triple axis or 3D sensor.

Triple axis meters are more expensive than single axis meters but the price difference is justified in our opinion.

Meters with a single axis or 1D sensor can measure only in one direction at a time, so in order to measure the total radiation you will need to measure separately in each of the three axes by rotating the meter accordingly and then calculate the vector sum or find the axis with the maximum value to roughly find the total value.

3-axis meters on the other hand calculate directly the total three-dimensional value. A 3-axis meter is much easier to use and helps you perform quicker and more accurate measurements.

The second most important feature is data logging, which means that the meter has the ability to store magnetic field measurements and calculate the average level of exposure at the end of the measurement session.

This feature is also pricey, but again very important, because magnetic field measurements vary greatly in time, due to the electrical load fluctuation on the power lines.

So in order to get a more reliable magnetic field measurement you should better be able to have a meter that records and stores data at least for 24 hours.

What about electric field meters?

There are very few meters that measure only low frequency electric field (such as the Digital Electric Field Meter (Cat. #A152-D) but because their price is high we find no reason to recommend them.

Also, even “electric field only meters” are only single axis.

Many magnetic field meters also offer electric field measurements and have cheaper prices than the “electric field only meters”, so we suggest you choose one of those if you need to also measure electric field meters.

Triple axis electric field meters are even more rare. Gigahertz’s NFA1000 is the only triple axis magnetic field meter which also offers triple axis electric field measurements in that price range.

Some more tips for electric field measurements

Electric fields are affected by all conductive materials such as the human body so it is not technically right to just hold the meter when measuring electric fields (although most manufacturers will not tell you anything about this).

Correct electric field measurements are performed either “potential free” or “grounded”.

“Potential free” measurements are technically more accurate and are performed by placing the meter on a non conductive holder which some companies offer.

“Grounded” measurements are performed by connecting the electric field meter to the earth pin of the electrical outlet or to metal piping or to outdoors soil (ask an electrician).

Grounded measurements are usually ~5 times higher than potential free ones.

Alternatively you can measure Body Voltage instead of electric field intensity by connecting a multimeter with the electrical ground and our body. The Body Voltage measurements are simpler and have the advantage that they show a total direct voltage value which is representative of the influence of the electric field in the whole body and not only in specific locations. See Body Voltage meters sold by Amazon, Less EMF.

Should my meter also measure DC fields?

The meters presented on this page measure AC (alternative current) magnetic fields created by power cables, transformers, electrical appliances etc.

DC (direct current) magnetic fields are created by the earths magnetic field, by magnetic scanners, tomographers, subwoofers, magnetized metal etc.

If you need only to detect the DC magnetic fields in order to avoid them (which is usually the case) you do not need to buy a DC field meter. A magnetic compass will detect any presence of artificial magnetic fields which interferes with earth’s magnetic field and deviates the reading of the compass. So if there is an artificial DC field, the needle of the compass, which normally points to the real magnetic north, will change direction.

If you need to measure DC fields, have in mind that most DC meters out there are single axis which makes the measurement even more difficult.

Some tips for professional users

  • There are meters in the market that are targeting professional users and are priced very high, though they seemingly offer the same features.
  • Some times, the increased price is justified by some extra features such as frequency analyzing, higher accuracy, data logging capability etc. Make sure you really need those features before you spend extra money on them.
  • On the other hand, more expensive meters usually also mean higher overall quality, more professional design, longer and more reliable operation, longer warranty, better service and the potential to get your meter recalibrated, which are important for professional users.
  • And your clients will value your service more if you use a high end meter, rather than a cheap one.
  • We suggest you try to avoid all in one combination meters. They do not perform well in all types of measurements.
  • Also, using more meters will make a better impression to your clients, than doing all the measurements with only one meter.
  • While smaller and lighter meters are easier to transport, bigger and heavier meters look and feel more professional.

Want to measure more types of electromagnetic fields? The only combination meter that seems to perform well in the 3 basic measurements (low frequency electric and magnetic, high frequency electromagnetic) is the new Trifield TF2 meter. See or combination meters article for more information.

How to measure radioactivity (ionizing radiation) - Geiger meter comparison guide

Easily measure the radioactivity of building materials, granite, medical equipment, from nuclear accidents, etc. with radiation meters, geiger counters, dosimeters that detect alpha and beta particles, gamma radiation, X rays etc. How to choose a measuring device.


rd1212radioactivitymeasurement 

Not the type of meter you are looking for? Please check our guides on low frequency meters (measure radiation from power lines, cables, transformers, electric devices laptops etc), high frequency meters (measure radiation from cordless phones, wireless modems (Wi-Fi), cell phone masts etc) or check the frequently asked questions about electromagnetic field meters!

We advise you to read all the following information about how to use a radioactivity meter and which are the important features to look for, but if you are in a hurry to see the recommended meters go straight to the radiation meters comparison table at the end of the article.

What do radioactivity meters measure?

Radioactivity or ionizing radiation meters measure the radiation from radioactive materials (subsoil, food, building materials, tiles, granite counters, nuclear accidents, ionization smoke detectors, medical equipment etc.).

The most common radiation meters are Geiger - Muller counters, which can record most or some types of radioactivity (gamma rays, X, beta particles, alpha particles etc).

For measuring the proven carcinogen radioactive radon gas (which is emitted from the soil, enters buildings by pipes and cracks and especially accumulates in low floors with inadequate ventilation), we recommend the use of radon meters, digital alpha particle counters, radon detectors or dosimeters and not Geiger counters. Radon gas consists mainly of alpha particles which most Geiger counters do not measure or measure inaccurately.

Read more about radioactivity and its effects..

Which are the main sources of radioactivity?

  • Building materials with highly radioactive materials (eg various ceramic tiles, granite counters, bricks, cement, pumice stones of volcanic ash, phosphogypsum, etc.)
  • Food with radioactive residues (eg vegetables, milk, meat and fish from the affected areas of radioactivity in Japan and neighboring regions - anything produced after March 12, 2011).
  • Phosphorescent watches, pottery, ionization fire detectors etc.
  • Kitchens that run on natural gas
  • Water from wells
  • Nuclear plants and reactors, especially after a nuclear accidents
  • Waste materials from various industries, hospitals etc.
  • Very high altitude (higher levels of cosmic radiation in mountains, aeroplanes etc)
  • Radioactive subsoil (higher rates of thorium, uranium, etc.)
  • Medical equipment (in radiodiagnostic laboratories X-rays, CT scans etc.)
  • Cement, aluminum and phosphate fertilizers factories, oil drilling and coal burning power stations

So far there have been recorded more than 152 radioactive leakage incidents in nuclear plants, industrial plants, during nuclear tests etc. [UNSCEAR 2008 REPORT: VOLUME I, page 15]. In many cases of nuclear leaks and accidents, such as the Chernobyl accident, the public is informed too late, resulting in not enough time to take precautions. With a radioactivity meter can you see first every increase of radioactivity levels in your area!

What features to look for in a radiation meter

Manufacturer

A reputable company or country of manufacture could mean better quality and extended operating life. Being more geographically close might be helpful if there is a malfunction of the meter or you need to send it back for recalibration.

Average price

This is the average price of the meter sold by the various online sellers shown on the bottom of each table.

Types of radioactivity detected

Each meter detects a certain portion of the radioactive spectrum. None of them can detect everything.

The main radiation types are:

  • Alpha particles: particularly dangerous when ingested through eating or inhalation (radon) through the air. They can easily be shielded even with a piece of paper.
  • Beta particles (or electron radiation): dangerous especially when ingested through eating or inhalation through the air. They can be shielded with a metal foil (e.g. aluminum).
  • Gamma rays: electromagnetic radiation emitted during radioactive decay (along with alpha and beta radiation) - they have high penetration and can travel several meters in the air. They can be shielded with thick cement, lead, steel etc. They are a big part of terrestrial radiation.
  • X rays: very high frequency electromagnetic radiation generated when a strong electron beam bombards a metal inside a glass tube, which is generated mainly by artificial sources in medical diagnostics etc - they have high penetration and can travel several meters in the air. They can be shielded with thick cement, lead, steel etc.

Gamma rays (along with radon gas concentrations which are better measured by radon meters, digital alpha particle counters, radon detectors or dosimeters and not radiation, radioactivity or Geiger counters), are the most important for building biology assessments.

Some manufacturers also mention the energy resolution of the meter measured in kiloelectron (keV) or megaelectronvolt (MeV) = 1000keV = 1000000 eV. So beta radiation detection 0.25 –3.5 MeV means the meter can detect beta particles with energy from 0.25 up to 3.5 MeV.

Radiation detector type

There are various types of radiation detectors which use different technology to measure radiaoactivity.

  • Geiger-Müller Tube detectors: They use a gas filled tube with a high voltage wire which collects the ionization caused by radioactive radiation. This technology is used by the most common radioactivity detectors, called Geiger counters, which have low sensitivity and low cost. Geiger-Müller Tubes usually use detector windows with thin silicate sheets (Mica) which are relatively transparent to radiation (such as alpha particles) but impervious to most gases.
  • Scintillation Counters: They use crystals that generate light when they interact with radiation. They offer more accurate measurements but are pricey.
  • Other types: Silicon detectors, Neutron detectors, Semiconductor detectors etc.

Units of measurement

The active equivalent dose (in Sv-Sivert), measures the effect of radiation on the human body since it takes into account the type of activity (e.g., beta particles, gamma radiation, X, etc.) and the absorbtion by the human body. Other radiation dose unit used is the rem where 1 rem = 0,01 Sv or 1 Sv = 100 rem.

Most radioactivity meters record the effective dose rate of radioactivity, usually measured in μSv / h or uSv/h (micro sivert per hour) or mR/hr (milli rem per hour) = 1000μR/hr = 10μSv/h.

Some meters also measure CPM (counts per minute) which is the number of atoms in a given quantity of radioactive material that are detected to have decayed in one minute. Count rate measurements are normally associated with the detection of particles, such as alpha particles and beta particles.

Measurement range

We recommend the radiation detector can measure at least from 0.1 μSv / h = 10 μR/hr = 0,01 mR/hr (natural background radioactivity levels) up to 10 μSv/h = 1000μR/hr = 1mR/hr (recommended safety limit for occupational exposure levels).

Measuring up to 100 μSv/h = 10000μR/hr = 10mR/hr is not necessary, unless you need to measure very high levels of radiation.

What are safe levels of exposure to radiation?

Radiation dose rate

Normal radioactivity values in the environment are <0.3 mSv / h (eg 0.13 μSv/h is the world average exposure to natural sources of radiation - except for radon [UNSCEAR, the United Nations Scientific Committee on the Effects of Atomic Radiation, www.unscear.org/unscear/en/faq.html] and values greater than 0.4 μSv/h trigger radiation alarm in Finland).

The exposure limits set by the legislation are:

European safe level for occupationally exposed 10 μSv/h (20 μSv/year - 2000 working hours per year) [Radiation Protection Regulations, OG / w / 216 / 6.3.2001 (whole body exposure)]

Potential health effects depending on the dose rate radiation 

  • 100 μSv/h: increased chance of illness
  • 100 000 μSv/h: nausea, vomiting (radiation sickness)
  • 1,000,000 μSv/h: increased chance of cancer
  • 10,000,000 μSv/h: organ damage and death within hours

The US Nuclear Regulatory Commission (NRC) identifies as high radiation areas in nuclear power stations after a nuclear accident when we exceed 1000 μSv/h [Wikipedia, Orders of magnitude (radiation)].

Radiation dose

Multiplying the dose rate with the total exposure duration we can specify the total radiation dose for a time period.

According to the Scientific Committee of the United Nations on the Effects of Atomic Radiation (UNSCEAR), the effects of radioactivity on humans per radiation dose are as follows:

  • <10 mSv: There is no direct evidence for health effects
  • 10-1000 mSv: No direct impact, increased incidence of certain types of cancer in exposed populations at higher doses
  • 1000-10000 mSv: Nausea, vomiting (radiation sickness), probability of death, increased incidence of certain types of cancer in exposed populations
  • > 10000 mSv: Death

Examples of radiation dose rates:

  • 10-hour flight by plane: 0,03 mSv
  • Chest X-ray: 0,05 mSv
  • CT: 10 mSv
  • Radon (annual report): 0,2-10 mSv (average 1,26 mSv)
  • Subsoil (annual report): 0,3-1 mSv (average 0,48 mSv)
  • Food (annual report): 0,2-1 mSv (average 0,29 mSv)
  • Cosmic radiation (annual report): 0,3-1 mSv (average 0,39 mSv)
  • Total annual radiation exposure from the natural environment: 1-13 mSv (average 2,4 mSv)

Data logging

Some meters offer the possibility to store the measurements and then download through a PC. We personally think this feature is not important for most users.

Display

A digital display gives you more accurate readings and has a more modern and professional look. Analogue displays are rather outdated, but are usually cheaper and will also do the job.

Backlight display

Not a necessary feature but is helpful when measuring in dark areas or in houses with no working lights.

Audio signal

Having audio signal which increases volume according to the radiation value, is helpful for finding radiation.

Audio alarm

Audio alarm is helpful for finding radiation hotspots but not necessary when you have audio signal. Some meters also allow you to set the alarm threshold.

Accuracy

Higher accuracy is good but it is more important for professional users and not for amateurs. Also, manufacturers show their accuracy data in various ways, making it difficult to distinguish the ones with crappy accuracy.

Batteries and battery life

If you plan to use the meter a lot then you should definitely take into account the battery type and life of the batteries used, because changing batteries frequently could elevate the operating cost significantly. Some meters are rechargeable so you don’t have to purchase new batteries every little while.

Low battery indication

Warns you about low battery so it helps you not run out of batteries unexpectantly.

Auto power off

Helps you avoid battery loss when you accidentally forget the meter on.

Carrying case

A good quality plastic case is very helpful for professionals or for those who frequently measurements in various locations.

Calibration service

If you need to check that everything works well in the future you might consider sending it for calibration (or recalibration if the meter was originally calibrated). This is especially important for professional users. In that case you should choose a manufacturer that offers this service. Also it would be better if the manufacturer is geographically close to you.

Warranty

The longer the warranty the better, especially if the meter is expensive.

Seller

We try to we recommend reputable companies, with good customer service, that can ship the meters worldwide.

Being more geographically close might be helpful if there is a malfunction of the meter, so we usually recommend one seller from the USA and one from Europe.

Also, buying from an overseas company means there will be some extra shipping costs and possible tax charges in the customs office.

Finally, please be sure to check all the mentioned features (warranty, prices etc) also in the sellers page, because they could be different from those mentioned in the following comparison tables or have changed since the time this article was written.

What you should know about modern day electrosmog

Why has our exposure to electromagnetic fields increased significantly in recent years? What are the main radiation sources today? How is human health affected? Are we protected by existing legal safety limits? Why many scientists warn about the dangers of uncontrolled use of technology, particularly by pregnant women and children? How to protect yourself.

Read more..

How to measure electromagnetic radiation

Why buy an EMF meter? How to choose the right one - Which features to look out for and for which you should avoid overpaying - How to use the meter - Is there a device that measures all types of radiation? Are radiation measurements only needed when there is a significant radiation source nearby? Which radiation values are considered high and where are they usually recorded?

Read more..

How to reduce your radiation exposure

Simple tips and solutions to easily reduce your daily exposure to artificial electromagnetic fields from cell phone masts, mobile and cordless phones, wireless modem-routers (Wi-Fi), electric appliances, electrical cables, power lines, transformers, laptops, tablets etc.

Read more..

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What you don't know about the new "smart" power meters

Do you have "smart" meters installed your house? Are they safe? How much radiation do they emit? Do they health? Are they vulnerable to hackers attack? Are there alternatives? Are there ways to avoid them? Smart grid - Smart Meters -...

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Are you exposed to elevated electromagnetic fields? These are the main radiation sources today..

Did you know that... The levels of electromagnetic radiation in indoor and outdoor areas have increased significantly in recent years? There are now cell phone masts in almost every neighborhood, usually camouflaged in chimneys, heaters, signs...

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How to find a property with low radiation levels

What to look for when searching for a property with low electromagnetic field exposure What are the disadvantages of low and high floors With which radiation sources you should avoid proximity with and what are the safe distances Which...

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How to shield your house from electromagnetic radiation

Protect yourself from the electromagnetic fields of cell phone masts, WiFi networks, etc. with innovative shielding materials. How to use special reflective paints, window films, fabrics, canopies, curtains and meshes. How to measure the...

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What you don't know about the effects of radioactivity

What radioactive sources surround you what are their effect on your health? What does the Radiation Hormesis theory claim; Which kind of ionizing radiation is a proven carcinogen? Are there risks from the nuclear accident in Japan? How to...

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Radiation from cordless phones, Wi-Fi routers, tablets, laptops, smartphones: Health effects and safer alternatives

Are there health effects due to the radiation of wireless modems, phones, tablets and laptops? How you can reduce your daily electromagnetic exposure? How to avoid radiation from neighbors wireless devices? Are there safe alternatives...

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Wireless Free Ζones in houses, hospitals and hotels? How to create them

Why are areas with zero wireless radiation are necessary to a part of the population? Which countries are developing Wireless Free Zones in hospitals, hotels and shelters? How to create an area without radiation in your home or office...

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Shocking warnings for the effects of modern day electromagnetic radiation sources

How do cordless phones, modems (Wi-Fi), mobile phone masts, electricity cables, baby monitors etc. affects us? What do the European Parliament, the Russian Committee for the Protection from Non-Ionizing Radiation, the World Health...

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Cell phone masts radiation health effects - How to protect yourself

How much radiation do cell phone masts emit? Why are they frequently camouflaged? How can you detect the cell towers in your neighborhood? Are there are health effects? Who benefits from their installation? How to protect...

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Power lines and transformers: Health effects and safe distance

How much radiation do power lines, high voltage pylons and transformers emit? Which levels of electric and magnetic fields cause effects on human health and when are exceeded? Which source is the most common cause of elevated magnetic...

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Electrohypersensitivity: What you need to know about the allergy of the 21st century

In the past it has been called "yuppie flu" and "microwave disease". Its symptoms include unexplained allergies, whistling in the ears, tachycardia and cardiac arrhythmias, fatigue, numbness of the head, constant headaches, etc. Are you...

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Is electromagnetic radiation dangerous for children and pregnant? A cause for rise in autism?

Are there health effects on children and pregnant women from the radiation of mobile phones, wireless modems, laptops, tablets, cell phone masts, power cables etc; What's the connection with the modern rise of childhood cognition and...

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