Patent ID: 8760221

Claim:
A method for reducing the noise in an output signal from a capacitance diaphragm gauge (CDG) that operates in response to a signal source that generates an input signal at a predetermined frequency and amplitude, the method comprising: amplifying the output signal from the CDG; converting the output signal to N digital samples during a duration of a first predetermined time segment; converting the output signal to N digital samples during at least one additional predetermined time segment, each additional predetermined time segment having a duration corresponding to the duration of the first predetermined time segment; averaging each digital sample in the first predetermined time segment with a corresponding digital sample in each additional predetermined time segment to generate N averaged samples; converting the input signal to N digital samples during a time segment having a duration corresponding to the duration of the first predetermined time segment; normalizing the N digital samples of the input signal with a maximum amplitude of the N digital samples to generate N normalized samples of the input signal; multiplying each of the N normalized samples of the input signal with a corresponding one of the N averaged samples to generate N digital products; averaging the N digital products to generate an average product; and generating an output signal responsive to the average product, the output signal having a value representing a pressure applied to the CDG.