Signal Conditioning Circuits. Bridge Circuits
Ref. DH Shingold, Transducer Interfacing Handbook
Vbridge = Vin · x/4 for x << 1
Null-type measurements are principally used in the feedback systems. Such systems seek to force the active elements (Strain gage, RTD, and thermistor) to balance the bridge by influencing the parameter being measured.
The resistance ratios in two branches determine the differential voltage output.
Analog I/O Design ..
Above this frequency, thermal noise is the primary circuit internal noise contribution. For
The choice of an instrumentation amplifier is based upon a selection of parameters that will minimize the error budget. Criteria include CMRR, input offset, noise and drift parameters.