The mooney viscometer is a shearing-disc viscometer, which permits to measure the Mooney viscosity, Pre-curing (scorch) and Stress Relaxation Characteristics of uncompounded or compounded rubbers.

The test is carried out by measuring the torque, which has to be applied under specified temperature and pressure conditions, in order to rotate a metal disc at 2rpm speed in the cylindrical test chamber filled with rubber.

The resistance offered by the rubber to this rotation is expressed as the Mooney viscosity of the test piece.