Identification and Correction of Artifact in the Measurement of Pulsed Magnetic Fields

AC magnetic flux density meters usually integrate a high-pass filter with a very low cutoff frequency (1-30 Hz) aiming at reducing the effect of slow oscillations. This can distort the actual time domain behavior of magnetic flux density waveforms detectable close to industrial or medical devices, even causing artifact high-amplitude oscillations. This paper proposes a procedure to identify the filter parameters that accurately reproduce its measured frequency behavior and suggests an algorithm to correct, in time domain, the field meter recorded waveform. Identification and correction procedures are extensively tested on magnetic flux density waveforms provided by a system for the generation of standard magnetic fields. Finally, the uncertainty associated with the identification and correction procedure is assessed by means of the Monte Carlo method (MCM). Assuming an overall standard uncertainty associated with the MCM model inputs of 0.3%, a standard uncertainty of 0.75% associated with the mean-square error between measured and reconstructed waveforms is obtained.