A differential amplifier specifically designed for use in measuring circuits.

a differential amplifier that has been optimized for use with DC signals

a differential op-amp circuit

a high-impedance differential amplifier with high common-mode rejection

A circuit whose output voltage with respect to ground is proportional to the difference between the voltages at its two inputs.

An instrumentation amplifier is a type of differential amplifier that has been specifically designed to have characteristics suitable for use in measurement and test equipment. These characteristics include very low DC offset, low drift, low noise, very high open-loop gain, very high common-mode rejection ratio, and very high input impedances. They are used where great accuracy and stability of the circuit both short- and long-term are required.