An example of an instrument used to measure the fields at low frequencies in this work is the EFA-300 Isotropic Field Analyzer, which is an ideal analyzer for workplaces and public spaces. This analyzer is capable of handling any measurement in the low frequency range and in addition provide a field analysis using the Fast Fourier Transform (FFT) computation.
The EFA-300 also includes an isotropic, cubic shaped electric field measurement module that contains both the sensor and circuitry necessary to operate it independently from the base unit. This is of great advantage as human influences on the electric field measurement can thus be reduced. The most common mode of operation of this instrument, is the Field Strength Broadband mode which can provide an indicative reading of the field within the range of 5Hz to 32kHz providing values of the peak and RMS field strengths. Additionally, a direct evaluation of the field’s spectrum is also performed by selecting the Spectrum FFT mode.