Frequency counter

摘要

A frequency counter having particular utility for processing the output of proton precession magnetometers divides a signal to be counted into a large number of consecutive elements each of an integral number of half cycles, and counts the increment in total elapsed duration of the signal represented by each sample. The counts are stored, and the stored counts are then manipulated to provide a least squares approximation of their mean, and the standard deviation of that mean. The counter can provide enhanced accuracy, as well as an indication of the reliability of the readings obtained.