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Best EMF Meters to Measure Home & Wireless Radiation

A comprehensive buyer's guide for choosing the right meters to measure both wireless and hard-wired EMF sources. Find out about exposure limits safety advocates recommend, features to consider, and how to interpret the technical info on product spec sheets.

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September 21, 2020

While your eyes may furnish the first line of defense in detecting sources of harmful EMF's (cell towers, antennas, Smart meters, routers, etc.), increasingly many sources of electromagnetic radiation are being hidden from view. New 5G cell phone towers, for instance, don't use those big propagating units (called magnetrons) that adorn the sides of 4G towers. The towers look like fat poles, with some sporting slightly larger cylinders on top. Meanwhile, hundreds of thousands of 5G "minicells" have been mounted worldwide in the past two years and are even harder to spot. These units are packed in plain plastic boxes and attached to bus shelters and the sides of buildings. Closer to home, banks of Smart meters shoot out potent magnetic fields ten thousand times away at apartment complexes, either mounted on a back wall or stuffed in a locked closet beside the elevator lobby.

Just as you'd want to pack a docimeter when traveling through Fukushima or Chernobyl, you should consider acquiring an EMF and/or RF meter for detecting EMF's in the everyday world we call home. And for anyone planning to implement shielding solutions to block EMF's they're already concerned about, one or both of these meters will be needed to test whether these mitigations are effective, make no difference, or actually worsen your exposure.

EMF emissions are generated by electrical components, wireless electronics, and even solar panels (although most of latter are perched on the roof, posing minimal risk). Even stereo speakers or dimmer switches on the wall can bite you with a potent EMF. Besides that, you may live near electric train lines or ride a subway powered by a high-voltage third rail producing EMF radiation. Since both wireless and AC hard-wired sources operate on a wide range of frequencies, finding the right meters to measure all this can be a daunting task.

Be forewarned, understanding EMF meter technology can be an adventure. Unlike measuring your basic circuit with the two leads of a multi-meter, radiation is not so neatly contained. Instead, electromagnetic fields hover like clouds around almost every electrical source that's not encased inside a thick metal box. While these fields remain stationary, wireless microwaves are constantly moving through space, posing a greater challenge to quantify. EMF's are measured with sensors, antennas or probes, and the resulting field strength (or power density) is expressed either in units of gauss, volts, or as watts (or volts) per meter of distance.

The Electromagnetic Spectrum, part of which is shown above, divides hard-wired and wireless equipment according to the number of waves they generate per second, otherwise known as frequencies. The measuring unit of frequency is the hertz. One hertz equals one complete wave. Five gigahertz represents 5 billion waves per second

Of course, the first thing you need to know here is that there are several different types of EMF and Radiofrequency (RF) meters that measure electromagnetic radiation. Although combination meters are also available to do double or triple duty, here are five basic categories to remember:

    An AC EMF meter, also called a gauss meter, detects magnetic fields hovering around powered-on appliances, lighting, electrical panels, switches and other components, as well as utility wiring and electric boxes. A gauss meter can also measure radiation around electrical substations; public transit light rail lines, subways and electric trains; industrial and portable power tools; generators and motors. These meters cover a range of frequencies on the low end of the frequency spectrum, typically 3 hertz to 2000 hertz, but sometimes higher. Around your home, school or office, you'll find most magnetic fields (but not all) oscillating in the 60 hertz range (or 50 hertz in foreign countries). Readings are expressed in units of gauss (in the U.S.) or teslas (in other countries).

    An AC EMF electric meter measures electric fields, which is produced wherever there's voltage present. In your home, all your wiring is energized with voltage even when no loads are connected to the wall outlets. The other most common EMF in this category is the high-voltage transmission line, which has been linked by some researchers to childhood leukemia. An electric field meter expresses readings in volts per meter.

    An RF meter measures wireless microwaves in the radiofrequency section of the Electromagnetic Spectrum. EMF's include cell phones and towers, all wireless electronics and appliances, routers and Smart meters. Radars, AM/FM/Short Wave antennas and weather monitoring stations all generate microwaves. The range of transmission freqencies an RF meter has to cover is extensive. Most consumers purchase one with a standard range of about 800 megahertz to 2.4 gigahertz. These frequencies cover cordless phones, Smart meters, and most mobile phone/WiFi communications. However, the new 5G technology, autonomous driving communications, flight radar and weather stations require an RF meter that measures between 5 and 12 gigahertz. Readings are usually expressed either in volts or watts of power per meter.

    While a line meter doesn't measure electromagnetic fields per se, it can pick up high-frequency voltage transients (HFVT's) in utility wiring. HFVT's generate harmful EMF's and are generally classified under the heading of "dirty electricity". This catch-all phrase covers anomalies in electrical circuits that produce both EMF's and live current in places where they don't belong. HFVT's are most often caused by some high-frequency electronics plugged in somewhere to the utility line, either within a ratepayer's property or on the grid infrastructure managed by utility companies. Traditionally, diagnosing HFVT's required a spectrum analyzer, but this equipment is generally used by electricians hired to troubleshoot and repair faulty wiring and circuits. Today, homeowners have the option of simply buying HFVT plug-in filters to suppress the transients room by room. Filters can be purchased from one of two companies, Stetzer or Greenwave, which also sell proprietary line meters to diagnose HFVT's.

    A DC EMF meter measures magnetic fields in DC-powered electronics and vehicles. Since Direct Current has no frequency, measuring it requires a different way to capture and quantify the EMF's strength than the method used in AC EMF meters. Any solid-state electronic device (laptops, stereos, clock radios, etc.) operates on Direct Current. So does all the electronic equipment and computers packed into a car or other vehicle. When you consider that virtually all LED displays (including TV screens), batteries, circuit boards and large stereo speakers produce substantial EMF's, it would be nice if we could measure them.

    Unfortunately, the minimum field strength that a DC EMF meter will read is typically 1000 milligauss. The same is true for a simpler, non-electronic measuring tool known as the magnetometer. According to EMF safety advocates, EMF radiation is harmful beginning at 10 milligauss, making both options unacceptable for measuring potential health risks.

What Meter Should You Buy?

Building inspectors and electricians likely own a separate meter to measure each of the first four EMF categories mentioned above. Spending a few thousand dollars on professional equipment is necessary for these tradespeople. However, affordable EMF meters designed for consumers have recently entered the market. Some use LED lights and/or audio alarms to alert you when harmful EMF's are detected. And several models combine magnetic, electric and RF measurements into one meter.

That said, the technology inside these budget-minded products cannot be described as finely tuned and calibrated electronics. These meters generally sport a high error range and lots of critics, including the German the consumer agency Wissenschaft sladen Bonn e.V. (WILA Bonn) which tested several models and then refused to recommend any of them for purchase. Regardless, at least two are big sellers in the United States: the Trifield TF2, a combination meter sold by Alpha Labs for under $200, and the Acoustimeter, which measures a wide range of wireless frequencies and costs about $400. (You'll find more info on these and other popular models after the section on specs and features below.)

The American lab instrument company, Extech, sells a line of EMF and RF meters, including the EMF 450 combination meter.

It's also important to note that the standards for what constitutes a "safe exposure limit" vary among manufacturers and countries. In the case of products that employ LED lights or alarm beeps to rate levels of radiation from safe to harmful, this is a big deal. That's because official standards typically require nearly a thousand times more radiation to warrant a safety advisory than what's recommended today by most EMF safety experts. Of course, some products do use the lower limits, so the lights and beeps and may be helpful. But this underscores the need to carefully review both product specs and safety standards before choosing a meter.

And if you're unable to either use a meter yourself, or afford to buy one new, here are some other options to consider:

Hire a home biologist, electrical engineer, EMF-savvy electrician, or EMF safety consultant to scan your indoor and outdoor environments to uncover danger zones with professional meters. Based on their findings, these folks can advise you on prevention and mitigation strategies to address any harmful EMF's.

Rent professional meters from an EMF product company, consultant, or electrical repair shop that has operates a loan program. The EMF Center (in California) is an example of a company that rents meters by mail, but if you poke around, you may find a local shop that will let you take one of their meters home for a week. Remember, you may need to rent the meters twice, first to detect the danger zones, and a second time to test whether or not any mitigation strategies you implement actually work.

Watch Ebay and Amazon listings for a used model (or open-box return) of any meter you're interested in. Alternatively, you can buy a meter new, use it for as long as you need it, then sell it when you're finished.

Buy an hour of consultation from an expert who can show you how to use your meter to take measurements. Check online for local EMF safety experts or college electronics instructors, or call a local computer repair shop to see if someone's available.

Safe Exposure Limits for EMF Radiation

Within advocacy circles, the recommended safe exposure limits for EMF radiation include Germany's Standard der Baubiologischen Messtechnik's guidelines issued in 2015, abbreviated as SBM 2015. This protocol covers a lot of other topics besides EMF radiation (like mold, radon, etc.) To cut to the chase, however, you can follow this simple chart listing the principle limits recommended.

A summary of the German Building Biology Institute EMF exposure limits established in SBM 2015. Note: Because European nations use tesla units (in this case, nanoteslas), you'll have to convert these to gauss. It's an easy conversion, i.e. 1 Nanotesla (nT) = 0.01 Milligauss (mG). The standards above also focus on "sleeping areas". Experts suggest that undisturbed, EMF-free sleep is critical to normal cell function and recovery from the previous day's exposures.

How do EMF Meters Measure Radiation?

An EMF meters uses sensors, while an RF meter uses an antenna or probe to detect the concentration of electromagnetic energy hovering around (or moving through) a given area. Generally speaking, an EMF produces the strongest readings nearest to the source of its energy, then quickly fades in intensity the farther away it gets, in accordance with the Inverse Square law of physics. In the case of radiofrequency (RF) signals, a field is typically strongest nearest the antenna from which a signal is either transmitted or received. See Reducing EMF Exposures for a brief explanation of how to calculate field strengths at different distances using the Inverse Square law.

One exception to this law is hotspots. A hotspot develops when multiple wireless signals collide with each other in space. This concentrates their energy together, and that can pose a significant health risk even when there's no antenna or other EMF-emitting source nearby. To identify such locations requires methodical scanning of each room in a home, school or workplace. An RF meter equipped with an audio feature is particularly well-suited for this task.

Meter Specs and Features

When choosing a meter to purchase, your main objective is to determine if you can trust the a product to accurately measure EMF's within the range of field strengths that includes the safe exposure limits you'll be using (e.g. SBM 2015). Your second concern is to make sure the range of frequencies and other primary capabilities of the meter fits all the devices and equipment you plan to test. In the average scenario, an AC EMF (gauss) meter for hard-wired radiation and an RF meter for wireless microwaves will be required to get the job done. As stated earlier, you may need to consider buying two RF meters in order to capture the new 5G technologies, which require a high range of at least 6 gigahertz. On the low end, cordless DECT phones and Smart meters operate in the 800 to 950 megahertz range).

After you've honed the possibilities down to a dozen or so meters that fit your main objectives, you'll want to explore the features, specs and accessories described in the product literature and spec sheets for each. Here's a quick run-through of what to expect:

Features

    Antenna or Sensors: Sensors are used primarily in magnetic and electric EMF meters, while antennas or probes are used for RF meters. While sensors are typically housed inside EMF meters, the antennas or probes on RF meters produce more reliable measurements when they protrude out the top of the product casing. An antenna may be either omni-directional (scans both the vertical/elevation plane and the horizontal/azimuth plane) or uni-directional. Sensors are either triple-axis, which means they scan for EMF's in three directions at once, or single-axis, which only scan in one direction covering about a third of a circle. (This means taking three measurements, then adding the readings to get a total field strength for that one spot.) While an omni-directional antenna or triple axis sensor saves you time and math, a uni-directional antenna or single-axis sensor would still be needed to locate the EMF source. Some gauss meters, like the ones Alpha Labs sells, provide the option of measuring in both the triple-axis and single axis modes.

    Coverage areas for omni-directional versus directional antennas on RF meters.

    Meter Display: Display screens are typically squeezed into small rectangular openings at the top or middle of the meter face. The bigger the screen, the easier it is to read, especially when displays are loaded with multiple numbers and graphics. Companies like Gigahertz Solutions, Alpha Labs and Extech do a better job with this. However, products like the Acoustimeter and Cornet meter present additional data that many users find helpful.

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    Which display do you prefer? From left to right, RF meters from Gigahertz Solutions, Cornet and Acoustimeter.

    Controls, buttons and menus: The more of these the better, but they usually come at a price. Some controls allow you to pick one of several operating modes. For instance, a good meter will let you switch between several frequency ranges in order to get either a more finely tuned measurement, or in the case of strong fields, a coarser reading. Menus are another nice perk, allowing you to easily change default settings, such as the measuring units (e.g. gauss or tesla) and audio features (such as alarm thresholds). While meters without flexibility can save you a lot of money, you need to make sure that their default settings fit your needs. Otherwise, they may be a hassle to adjust each time you power on.

    Audio: Hearing EMF's is as invaluable as the rattle of a Geiger counter when you enter a nuclear danger zone. But not all meters sound alike. The cheaper ones simply squeal like a puppy at a high reading. Better models convey a variety of telltale sounds, such as the rat-a-tat of pulsed waves from a cell tower. That helps identify the source of an EMF. Some meters also include headsets, which is a great perk, enabling you to be more discreet when using the meter in public places.

    Data Logging / Transfer to PC: If you want keep records of your readings, this feature lets you do that. However, what this data dump looks like depends on the model. Be sure to find out before shelling out any extra dollars.

    Memory: Many meters will hold onto a certain number of readings before deleting them. Alternatively, some allow you to save readings you specify.

    Backlight: Nice to have if you're working in the dark.

    Available Accessories: Some of the better RF meters, including those made by Gigahertz Solutions, offer a variety of extra tools you can attach to a meter to expand its capabilities. For instance, you may want to change an omni-directional antenna for a uni-directional one in order to locate the source of an RF signal. Other accessories include "attenuators", which enable a meter to measure higher signal strengths outside the product's normal range. A "pre-amplifier", on the other hand, enlarges weaker signals at or below the low end of the field strength range listed on the product's specs. (This device effectively expands the frequency range.) Be sure to evaluate all available accessories before ordering your meter, since buying everything at once will save on shipping charges maybe even score a discounted price for bundling up on products.

Specifications

    Meter Dimensions: Some meters are necessarily large to get the job done. This is the case of all the products sold by Gigahertz Solutions, especially its RF models equipped with "fish-skeleton" antennas. On the other hand, owning a more discreet, compact meter is preferable for going into public spaces to measure EMF's. These days getting hauled off in an armlock by overzealous security guards is well within the realm of possibility, so be mindful of your environment when conducting measurements.

    Ranges and Scales: Check these specs carefully to make sure that:

    • 1) the safe exposure limits you're using are within the ranges covered by the meter;
    • 2) the operating frequencies of all the EMF or RF sources you want to measure are covered;
    • 3)the field strength or power density range isn't a skimpy one; a gauss meter, for instance, should ideally range from one tenth of a milligauss to 1-10 gauss.

    Keep in mind is that ranges tend to be less accurate at the outer limits of the scale than they are in the center of it. So, if an electric field range begins at 1 volt, and the safe exposure limit is 1.5 volts, that may be cutting it a little close. (Sadly, few budget meter scales start below one volt.) Field strength remains a thorny issue with meters primarily because official exposure limits are on average a thousand times higher than SBM 2015 and other safety advocate recommendations.

    Sensitivity / Resolution: This spec refers to how far the meter sensor or antenna/probe can hone in on an exact measurement using incremental changes. For instance, a meter that reads voltages at quarter-volt increments is more sensitive (i.e. offers better resolution) than a meter with one-volt increments. In general, a field strength range should have finer increments for low-strength fields (like milligauss), and larger increments (gauss) when measuring stronger fields.

    Measuring Units: The better meters give you a choice of units. That way, if you don't like the default option (e.g. teslas), you can bring up a menu and switch to gauss in a couple seconds. The cheaper meters may not give you a choice, however, so make sure their choice is one you can live with it. Converting between gauss and teslas, as previously mentioned, is a snap, but only if you remember to do the math.

    Peak vs Average Measurements: RF meters often provide both types of readings, but peak measurements (the highest numbers you see) should be what you write down and respond to. That's because these EMF's, however short-lived, can still harm your health by way of their recurring nature. (A third option known as "Peak Hold" refers to a longer lasting, albeit still periodic EMF emission.) Knowing the average helps you determine how often the short intense bursts happen over the course of time. Incidentally, some of the cheaper meters only have one type of measurement, but may not say whether it's average or peak. Make sure it's the Peak option before buying the product.

    Accuracy: Usually this spec is expressed as a percentage. For instance, +/- 5 % for a reading of 100 volts, means the correct figure could be anywhere from 95 to 105 volts. (To be on the safe side, always record the higher number as your reading.) If the product literature has an accuracy spec higher than 5%, you may want pass on the meter. If no accuracy spec is provided, either contact the distributor or manufacturer to get the spec, or don't buy the meter.

    Some meters, like the Gigahertz Solutions and Acoustimeter models, express accuracy in decibels. If you're not a scientist, this won't tell you anything. Fortunately, on some distributor websites, the accuracy for GS meters is converted to a percentage. You should contact the sales department of either the manufacturer or local distributor to get the percentage if it's not provided in the literature.

    Sampling Rate: This tells you how often the meter takes a measurement. Because wireless waves and pulses emit energy for only a tiny fraction of a second at a time, RF meters especially need to sample often. Otherwise, potent EMF's might go undetected.

    Batteries: Make sure the ones used by the meter won't cost you an arm and a leg to replace. This spec should also tell you the life of one set of batteries before they need replacing. Most meters use either a 9-volt or 2-3 AA batteries. Some product use rechargeable batteries.

    Warranty and Country of Manufacture: If you're paying more than a hundred bucks for your meter, you'll want a warranty of at least a couple months. If you spend over $250, opt for one that has a one-year warranty. Something else to consider is the process of getting the product serviced. For instance, if your meter manufacturer is located outside the United States, doesn't offer local repair alternatives, or there's no free "800" phone number to call, having a warranty may not mean much. Also beware that buying a meter from a non-authorized distributor (like an Ebay seller) may void the warranty altogether.

Popular Products For Sale

Here are some of the current models promoted by EMF safety experts and currently sold online. For a listing of online seller websites, click on "More Resources" from the menu at the top right of this page (excluding the printable version).

RF Meters

Germany's Gigahertz Solutions offers the HF35C and HFW35C RF meters at affordable prices, but both products have limited range when it comes to microwave frequencies.

Gigahertz Solutions HF35C and HFW35C: These RF meters together cover a wide range of frequencies, 27 mH to 2.5 gH, and 2.4 gH to 6 gH respectively. GS is one of the better companies in the business and offers 2-year warranties. While the accuracy of these meters is not at the same level as the professional models (+/- 6 db compared to +/-3 db), most consumers can't afford the latter. GS user guides can also be downloaded from the product page and read before you buy a meter.

Gigahertz Solutions lists its catalog here so you can compare their ranges along the Electromagnetic Spectrum. Even better, Notice the various wireless equipment above the spectrum, a big help when it comes to picking a meter for the kinds of EMF's you want to measure.

The biggest drawback with the HF35C and HFW35C is that you really need to buy both of them to measure both 5g technologies and everything that came before that. The manufacturer may offer a bundle price, if you buy direct from Germany. Customers are likewise encouraged to email a salesperson and request a discounted price whenever ordering multiple items.

More info from Gigahertz Solutions.

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The Extech 480836 RF meter and the Acoustimeter AM 10.

Extech 480836:: This meter is the one used by the computer technician in the first video posted on the Watch Videos page. Notice the probe mounted outside the box, which makes for more reliable readings.. This model sells for under $300 and can pick up the lower safe exposure limit for EMF radiation, which is 1 microwatt per meter squared. It can also help you detect leakage from a microwave oven. The meter boasts good sensitivity but the manufacturer's website doesn't offer a spec for accuracy. Also, the high end of the frequency range it measures stops at 3.5 gh, higher than many meters but still unable to cover 5G. A newer model of this meter, the 480846, solves that quandary by extending the frequency range to 8 gh. Both models have audible alarms that can be adjusted to different thresholds. However the sound is an obnoxious squeal, which won't help you identify the signal source.

More info from mfg: www.extech.com

Acoustimeter AM10: The specs for this meter claim the device covers frequencies up to 8 gh. It also boasts good sensitivity and provides three different types of readings - peak (highest), peak hold and averaged (i.e. a time-averaged reading of the last 1000 samples). Unfortunately, the measuring probe is buried inside the casing. The AM10 offers an audible signal and more than a dozen LED lights to help you assess the danger level. It's red zone begins at 0.5 volts per meter (V/m), which complies with the Bioninitiative Working Group's 0.614 V/m exposure limit.

More info at emfields-solutions.com

Magnetic And Electric Field Meters

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The AlphaLabs UHS2 gauss meter and Gigahertz Solutions ME3030B Magnetic/Electric EMF Meter.

AlphaLabs UHS2. This gauss meter measures AC magnetic fields only. It's a triple-axis meter that also has a single-axis mode to help you locate the EMF source. The frequency range runs from 13 hz to 75 khz. The meter also has high sensitivity/resolution in its unit increments of milligauss. It's a pricey item, though not nearly as expensive as other models sold by this top-tier lab instrument manufacturer.

More info from AlphaLabs.

Gigahertz Solutions ME3030B: This meter can measure both electric and magnetic fields. It has single axis sensor, which means it requires three readings to get a total exposure figure. However, it's easier to pinpoint an EMF source. Because it's a European meter, it uses nanoteslas for measuring magnetic fields rather than milligauss. (There's a conversion chart printed on the back.) It costs under $200.

More info from Gigahertz Solutions.

Combination Meters

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The Cornet 88T combo meter and the TriField TF2 with a digital display.

Cornet ED88T Meter: Like the Acoustimeter, the specs for this product show a high RF range up to 8 gh and good sensitivity on readings, but the probe is similarly contained in the meter box. The ED88T is half the price, however. One nice perk is that the meter tells you the broadcast frequency of an RF emission, which is super helpful in identifying the source. It's EMF mode uses a single axis sensor for electric and magnetic field measurements. The magnetic field scale starts at .1mG, which is perfect. But the electric fields scale starts at 10 volts, too high for the safe exposure limit of 1.5 volts recommended in SBM 2015. The stated accuracy for magnetic and electric field readings is also pretty bad at +/- 20-25%. There's also an ED88T "plus" model which offers datalogging capability.

More info from electrosmog.com.

Trifield TF2: This meter replaced the popular Trifield 100 XE a few years back. Unlike the old analog meter, the TF2 sports an updated digital display and better RF accuracy reading accuracy at +/- 20% ( still not great). The RF probe is contained inside the box. For under $200, you do get a wide frequency range. Stated accuracy for magnetic field readings is +/- 4%, and electric fields +/- 5%, both impressive for a budget meter. The Tri-Field box is bigger and heavier than the other combo meters reviewed here, but comes with a backlight and a one year warranty.

More info from trifield.com.

To get a list of online EMF safety equipment stores, click "More Resources" on the menu above right, then scroll down the page.

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