EMF Meter

EMF Meter

EMF measurements are measurements of ambient (surrounding) electromagnetic fields that are taken with particular sensors or probes, such as EMF meters. These probes can be generally considered as antennas although with different characteristics. In fact probes should not perturb the electromagnetic field and must prevent coupling and reflection as much possible in order to obtain a precise measure. EMF measurements are nowadays becoming important and widespread in different sectors to assess environmental and human exposure to non-ionizing radiation in many contexts. There are two main EMF measurements types:

• broadband measurements performed using a broadband probe, that is a device which senses any signal across a wide range of frequencies and is usually made with three independent diode detectors;
• frequency selective measurements in which the measurement system consists of a field antenna and a frequency selective receiver or spectrum analyzer allowing to monitor the frequency range of interest.

EMF probes may respond to fields only on one axis, or may be tri-axial, showing componets of the field in three directions at once. Amplified, active, probes can improve measurement precision and sensitivity but their active components may limit their speed of response.