Proof mass

A proof mass or test mass is a known quantity of mass used in a measuring instrument as a reference for the measurement of an unknown quantity. A proof mass or test mass is a known quantity of mass used in a measuring instrument as a reference for the measurement of an unknown quantity. A mass used to calibrate a weighing scale is sometimes called a calibration mass or calibration weight. A proof mass that deforms a spring in an accelerometer is sometimes called the seismic mass. In a convective accelerometer, a fluid proof mass may be employed.