How Does An EMF Meter Work?

An EMF detector is one of the essential testing instruments for an engineer or a technician. These testing devices are often integrated into a multimeter, but do not provide a detailed analysis, and that’s where a full standalone EMF detector comes into play.

The detector can measure the presence as well as the strength of an electromagnetic field. They are often used in power industries to look for EMF disturbances within the power lines and in communication or related industries.

EMF meters or detectors are also used by the public with an intention to measure EMF radiation. As the governments have ruled the safe limitation, it’s not weird that people buy this one to recheck whether they are within that safe level or not.

Electrically charged objects generate electromagnetic fields. When exposed to particularly high electromagnetic fields, they manifest as a physical field that can affect nearby objects, such as other electrical devices and humans.

As we know that when measuring the EMF radiation, it means we are measuring about the magnetic field, electric field, and radiation frequency. So, these 3 things may be triggering us to wonder how an EMF works. If you are at this situation, then the following brief discussion may address your curiosity.

Working of An EMF Detector & Its Types

The EMF detector uses the ‘Electromagnetic Radiation Flux Density’ to measure the change in energy in the field. The greater the flux density stronger the electromagnetic radiation.

Due to its sensitive components within its construction, a slight change in energy is very easily detected by this instrument.

Actually, the sensor within the EMF meters do not directly measure the field in any given direction, they always measure the field in one specific direction.

Thus, EMF detectors are available with a single or tri-axis sensor.

Due to the nature of a magnetic field, a sensor will only detect it correctly if it is parallel to the magnetic flux field. A single-axis detector is less expensive but has only one sensor.

Single Axis EMF detector

Just as the name implies, a ‘single axis’ EMF detector can only measure electromagnetic fields in one specific direction.

In order to get a maximum reading, the meter must be rotated slowly within the magnetic field, which is a time-consuming way of measuring.

When the meter is rotated 90 degrees from the highest reading, it should read practically zero, indicating it has been placed perpendicular to the magnetic field.

3-Axis EMF detector

A 3-axis or ‘tri-axis’ EMF detector uses all 3 directions (X, Y, Z) to measure electromagnetic radiations. It’s more accurate than a single-axis detector as it does not require tilting or any other kind of adjustments.

A tri-axis meter has three sensors spaced 90 degrees apart. This ensures that no matter how it is placed in an EMF, the maximum reading is obtained.

As a result, the tri-axis models are significantly faster and easier to use, although they are slightly more expensive. Also, these 3-Axis EMF detectors are mostly used in industries to locate EMF spots in power lines or to find the ‘dead zones’ near a communication tower.

It’s important to note that the type of EMF meters to be used also depends on whether the output electromagnetic field is from AC or DC installations.

Standard EMF meters (electromagnetic field meters) are usually used to measure electromagnetic fields in AC systems, while gauss meters or magnetometers are required in DC systems.

The overall frequency of the electromagnetic field to be examined is also critical for the measurement. Conventional electromagnetic field meters are often designed to measure frequencies in the 50 to 60 Hz range, which is the common electrical frequency.

Some of these EMF detectors are capable of simultaneously monitoring and displaying magnetic fields, electric fields, and RF strength. The measurement unit and measurement types are presented in units of power density and electric and magnetic field strength.


While directing the detector’s front part in the direction of the preferred electromagnetic field area to take a measurement, the meter shows the electromagnetic field measurements of the individual (XYZ) and aggregated magnetic field readings at the same time.

The total field reading is expressed with the following equation:

Total field reading equation

All these calculations are done by the meter itself. The final result is displayed on the screen for the user to observe.


So now hopefully you are all caught up with how an Electromagnetic field detector works, what principles it uses and how many different configurations are available (Single or Tri-Axis).

For personal or low-level use, a ‘single-axis’ EMF meter is more than sufficient. However, for someone requiring more accuracy, a ‘tri-axis’ EMF detector is the way to go. You can also check our guide on the best EMF detectors/meters. It provides a detailed insight on top picks for the EMF meters available on the market.