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Op Amps for Gain, Offset and Function Modification

An operational amplifier can be used to provide the following signal conditioning:

  1. increase the amplitude of the signal,
  2. filter the signal,
  3. decrease the signal output impedance or
  4. provide a variable gain and offset control.

The latter is most useful for calibrating a transducer's output signal.

The dynamic range of a signal from an input transducer may be too large to process through the DAQ system (eg. the ADC is often the limiting factor). One can use a linear amplifier and choose to overflow or reduce the overall gain. The latter approach will cause a loss in precision. Another approach is to use a nonlinear amplifier, such as one with a logarithmic gain, .

Doug Gingrich
Tue Jul 13 16:55:15 EDT 1999