Saw torque and temperature sensor

A contactless SAW based torque and temperature sensor includes three SAW resonators mounted on a common substrate made of Y+34° cut of quartz. The first SAW has its principle axis inclined at +45° to the X-axis of the substrate, which, in use, is either aligned with the longitudinal axis of a device whose torque is to be measured or is perpendicular thereto, and the second SAW has its principle axis inclined at 135 degrees to the X-axis of the substrate. The third SAW is positioned with its principle axis inclined at an angle, preferably in the range of 0 to 30 degrees, to the principle axis of both the first 2 and second 3 resonators so that none of the SAWs are parallel, the third SAW enabling temperature measurements to be taken.