Meterk is a band name of Shenzhen Tomtop Technology Co., Ltd., established in 2004 in Shenzhen, China and is a manufacturer of arts and crafting shop equipment, electric tools, and electrical testing equipment. Whereas their main focus is on small 3-D printers and cutting tools, they also produce electric tools (saws and drills) and several types of meters, such as digital multimeters, a socket tester, a cable tester, a moisture meter, distance meters, a metal detector, and EMF meters. Their EMF meter is the subject of this review.
A Deep Dive into the EMF Meter by Meterk
The EMF Meter by Meterk is a single-pole, dual-use EMF meter that can simultaneously measure electric field strength and magnetic radiation intensity, as well as report local air temperature near the device. It is small and lightweight, weighing 3.78 ounces (107 g), and is about the size of a television remote or older, pre-smartphone cellular phone.
The EMF Meter is powered by three AAA batteries and has a multifunction LCD display that is easy to read. The sampling rate of the device is very quick and when activated takes a read every half a second.
The device operates at 50/60 Hz and can measure EMF from 30 Hz to 300 Hz. The device is intended for both professional and consumer use and is a handy addition to the arsenal of any person who needs to take device or area surveys for certain types of EMF (explained more below).
What is EMF?
We will have a quick review here of what exactly is EMF because this factors heavily into our discussion below. When we say EMF or electromagnetic frequency, it is both a specific term and an extremely broad one.
It’s like saying “water”, but water can be several things: a solid, the liquid you drink and bathe in, or an invisible gas (by the way, steam is invisible, and what people call “steam” is actually a mixture of steam and water vapor called a colloid: floating liquid droplets of water mixed with air and water-gas). EMF is basically any photonic energy in the electromagnetic spectrum.
These energies are emitted as wave-like energies that also can behave like particles (that’s particle-wave duality, way beyond this review). Those energies are described by several features, which include frequency (measured in cycles/second or Hertz, Hz), wavelength (measured in nanometers, nm), and intensity (measured in either Tesla’s [T] or Gauss [G] units, typically micro-Tesla’s [μT] or milli-Gauss [mG]).
Frequency describes pulses of energy and how often they are emitted, whereas wavelength describes the distance between those pulses as they travel. The frequencies of EMF range from radio wave frequencies starting at 3 Hz all the way up to gamma-ray frequencies of 300 EHz (exahertz, or 300×1012 Hz).
Long-wave radio is down on one end of the EMF spectrum, followed by television and radio signals, microwaves, infrared light, visible light, ultraviolet light, x-rays, and finally gamma rays. So, you may be asking where this is all going?
Certain sources of EMF are emitted in different frequency bands and lower frequencies can travel farther than higher frequencies unless compensated by higher energy output. This means a low-frequency short wave radio signal can travel a lot farther than microwaves when we are talking about straight line-of-sight (short waves can actually go a lot farther because over the horizon they bounce off the ionosphere and come back to earth on the far side, but that’s beside the point).
This also means that energies of high-frequency sources drop off faster than low-frequency sources over distance. You can think of it as waveforms only get so many waves going through the air, structures, etc. before they are mopped up by the surrounding environment.
Longer wavelengths get to travel farther. Dissipation of electromagnetic energies over distance also follows the inverse square law, which basically states that the energy intensity drops off by a factor of 1/distance2. Things like radio and television transmissions run from 30 Hz to 300 GHz.
Cell phones and cell towers run from 900-1900 MHz. WiFi routers are either 2.4 GHz, 5 GHz, or both.
Anyway, the device we are reviewing here detects signals in a frequency range of 30-300 Hz, which is in the band for power lines and electrical circuits, sources that have lower energies.
Who’s It For?
The EMF Meter is designed as a serious EMF survey device for electrical sources. Although designed for commercial use, its affordability and accuracy make it ideal also for consumers who are concerned about limiting their EMF exposure from electrical devices and wiring in their home or workspace.
It is also an ideal device to take on the go if you suffer from electromagnetic hypersensitivity syndrome (EHS) since it is lightweight and portable. The EMF Meter can easily be slipped into a pants pocket or carried in a purse or backpack to take during travel so that new and unfamiliar spaces can quickly be surveyed for potential hazards.
Operation of the device is very simple and most relevant information is provided to the user in its default mode. The EMF Meter is also the least expensive effective EMF meter on the market.
What We Like About the Meterk EMF Meter
The EMF Meter by Meterk is a small, accurate, portable EMF meter that provides measurements in two different scales, μT and mG. It does this rather well, with only a 5% error, a basic standard for field equipment.
The addition of a temperature readout is unusual, but a nice touch. Although it does not relate in any way to magnetic field strength, we guess that the function was on the board, so Meterk threw it in.
The backlit display is also a nice thing, especially with the color shift from green to red when magnetic field readings are dangerously high (along with the audible alarm). We like the fact that the alarm threshold can be adjusted for different environments.
For example, a threshold in your home would presumably be a lot lower than a safety threshold in an industrial environment. Making the appropriate adjustment allows the user to custom tailor notification thresholds to the specifics of the environment being surveyed.
Since the EMF Meter is a single-pole device, direction and device orientation is an issue. Whereas other more expensive meters, such as tri-pole meters, report EMF in an area in general, a single-pole device allow the user to determine EMF intensity by distance and locate its source.
With a little practice and a bit of sampling, accurate area surveys can be conducted, mapping out any source locations, intensity, and orientation of any emitted energies. The battery saver feature is also a nice addition to the EMF Meter.
Users can either leave the device on for continuous survey or set the auto-off mode to prevent battery drain if they forget to switch off the device.
What We Don’t Like About the EMF Meter
In this section, we generally talk about the features of a device that we feel are poorly designed or are lacking. There are none with this EMF Meter and we like this little meter quite a lot.
However, a casual survey of internet reviews and customer comments indicates a general ignorance among customers as to what the EMF Meter is designed to do. The bandwidth is only 30-300 Hz, which means this is an SLF (super-low frequency) meter and will only detect electromagnetic fields emitted from power lines, computers, and electrical appliances.
If you are looking to measure EMF from cell phones, cell phone towers, telecommunications towers, WiFi routers, or microwave ovens, it will not see a thing (except you will get a reading from the WiFi and microwave as plugged-in electrical devices, not as a radiofrequency or microwave sources). The EMF Meter is not meant to be a radiofrequency sleuthing device but is intended to test electrical equipment for electromagnetic field emissions and leaks.
For example, if you place the EMF Meter near your WiFi router, you will get a reading. But if your router is wired to a device like your computer and the WiFi is disabled, you will get the same reading.
That is because the EMF Meter is responding to the current flowing through the router circuitry, not the radiofrequency emissions from the antenna which operate in a completely different frequency band at 2.4 GHz and 5 GHz. Caveat emptor.
- Affordable (it is the least expensive EMF meter on the market)
- Accurate (an error of 5% or less at peak detection band)
- Easy to use (controls are simple)
- Great display (large, clear display with a backlight if desired)
- Portable (fits in your pocket, purse, or backpack)
- Not a true “EMF meter” for the anti-EMF crowd, but is specifically designed for electrical appliances in a narrow frequency range
- Multifunction buttons can be confusing for some users
A Meterk EMF Meter
A manual in English, Mandarin, Italian, Spanish, French, and German
(batteries not included)
Overview of Features
Operating the device is very simple and there are only 4 buttons. The EMF Meter has a power button that activates by a long push to turn the EMF Meter on or off.
Upon powerup, the EMF Meter goes through a zero-calibration mode each time for reading accuracy. This button also has the ability to activate or mute the audible high reading alarm (to alert the user to unsafe conditions) by a quick push.
The “MG/UT” button allows the user to change reported units for field strength between magnetic field measurements in milli-Gauss (mG) or micro-Teslas (μT). The EMF Meter also reports area temperature. There is a “°C/°F” button to switch between Celsius and Fahrenheit readings.
The temperature button also functions to set the battery saver feature by a long press, which sets the EMF Meter to an “Auto ON” and “Auto OFF” mode. With this feature, after 10 minutes of no use, the device will automatically power off.
The threshold for the audible alarm can also be manually adjusted to different cut-off limits, as needed by the user. There is also a button for backlit display for use in low light conditions that is green, but switches to red with the audible alarm when there is a high reading.
The display also has a low battery indicator so that users know when batteries should be replaced to ensure accurate readings. Resolution is to 0.1 μT and 0.1 mG and device accuracy is rated at 5%.
In general, we like the Meterk EMF Meter for its ease of use and portability. However, users need to understand that the EMF Meter is designed for a specific purpose only, that purpose being the measurement of electrical fields around electrical machinery and appliances.
Users should understand what the EMF Meter measures and does not. It is marketed as an EMF meter but is sold along with digital multimeters and circuit testing equipment, so Meterk is not in any way practicing any sales deception.
The EMF Meter is marketed to engineers and electricians, not to people making EMF surveys of radio towers, cell phone towers, WiFi sources, and the like. Customers should be aware of what they are buying and what the device is designed to do.
Some negative reviews of the EMF Meter indicate that many customers simply do not know what they are buying. It would be like buying a hacksaw and complaining that it sucks at cutting firewood.
The color-coded screen of the EMF Meter and accompanying audible alarm are a great feature for notifying the user immediately of unsafe electromagnetic field levels. The ability to adjust that threshold for the alarm settings, or just to mute the audible alarm, is a nice touch since surveying in a high-energy environment would subject the user to hearing an alarm bell routinely and could become annoying.
The accuracy is great (5%) and the battery saver mode is a great fire-and-forget feature that will prevent the unit from going dead when it is needed for use. Being a single-pole device design is most appropriate for conducting focused surveys of electrical equipment.
With a little practice, area surveys can also be conducted with accuracy to map out the fields in a room or work area. For what it does, we feel the Meterk EMF Meter is the best deal available in an electrical circuit EMF meter.