Analog signal processing system with correction for amplifier offset

An analog signal processing system including an analog data acquisition subsystem for transmitting from remote locations at least one low-level analog signal;

• analog to digital (A/D) converter means responsive to said analog input signal for converting the said signal into a digital input signal, and
• a digital system for processing said digital input signal with said analog signal processing system comprising:
• means within said data acquisition subsystem for converting one low-level analog signal into a pair of time-displaced analog input signals having opposite polarities, with each input signal of said pair carrying information relative to the magnitude of said low-level analog signal;
• amplifier means successively responsive to each input signal of said pair of input signals for generating a corresponding pair of time-displaced amplified signals each having an offset error due to drift in said amplifier means;
• analog to digital converter means successively responsive to each amplified signal of said pair of amplified signals for generating a corresponding pair of successive digital output signals;
• a digital subsystem including means for algebraically combining said of a pair digital output signals to derive one digital measurement signal characteristic of said magnitude of said one low level analog signal;
• and
• means for digitally processing said digital measurement signal in relation to said data acquisition subsystem, in relation to said means for algebraically combining and in relation to said analog to digital converter means, whereby said offset error is substantially eliminated from said digital measurement signal.