A method is described for producing calibrated torques at low temperatures using the interaction between an applied magnetic field and a superconducting torus. The torque produced is proportional to the square of the applied magnetic field and can thus be varied continuously over a wide range by varying the current which produces the magnetic field. It can be used in a null method to measure any torques of interest, such as the torques produced by second sound on a Rayleigh disk or on a radiation balance. The principal advantages of this method are that a wider range of torques is available with a given assembly and that the null position is more easily obtained.