Patent ID: 8082800

Claim:
A contactless SAW based torque and temperature sensor comprising: a first and a second SAW resonator provided on a substrate made of a cut of quartz substantially in the range of Y+34°, said first SAW having its principle axis inclined at substantially +45° to the X-axis of the substrate, which, in use, is either aligned with the longitudinal axis of the device whose torque is to be measured or is perpendicular thereto, and said second SAW having its principle axis inclined at substantially −45° to the X-axis of the substrate; and a third SAW having its principle axis inclined at an angle to the X-axis of the substrate which is substantially equal to 30°, wherein each said SAW resonator is formed by laying a film of aluminum on the substrate having a thickness (h) and the SAWs have an average operating wavelength λ where the ratio h/λ is in the range 0.021 to 0.032.