Compact triaxial AC magnetic field analyzer/dosimeter using swept bandpass filters

摘要

A triaxial AC magnetic field analyzer/dosimeter instrument measures the field strength of three mutually orthogonal AC magnetic field components at a plurality of different frequencies in a frequency range of interest and stores corresponding data which may be processed to indicate the field strength at each of the frequencies and/or the sum of the field strengths over the frequency range of interest. The instrument is computer controlled and comprises three measurement channels corresponding to respective magnetic field components, each channel including a sensor coil, a clock controlled, switched capacitor, bandpass filter, and a TRMS detector. The passband of each filter is swept across the desired frequency range by a varying frequency clock.