PROCEDURE AND INSTALLATION FOR THE AUTOMATIC SUPPLEMENT OF FUNCTION NOISE IN THE MEASUREMENTS OF THE ENVIRONMENTAL SIGNIFICANCE OF INTERNAL COMBUSTION ENGINES

摘要

A system for automatically suppressing any ground noise present in the detection of periodic phenomena comprising detecting means for detecting the signal occurring just prior to the occurrence of the periodic phenomena, which signal is representative of ground noise, converting means for converting the sensed signal to a usable D.C. level signal, sampling means for sampling the signal resulting from the occurrence of the periodic phenomena, and summation means for algebraically adding the converted D.C. signal to the sampled signal for eliminating any ground noise present in the sampled signal, thereby providing an output signal representative of the periodic output phenomena free of any ground noise.