Introducing a New Method for Temperature Measurement by Magnetostrictive Position Sensors

Magnetostrictive position sensors (MS sensors) are based on a Time-of-Flight (TOF) measurement of an ultrasonic signal in a waveguide. These sensors can be used for absolute long-range as well as for high-precision linear position measurement. In the state-of-the-art, only the position or physically related parameters like velocity or acceleration are determined. In this paper, a method for temperature measurement is described, based on the highly temperature dependent reflections of the ultrasonic signal at the outer end of the MS waveguide, where a wave damping material is placed by design. The theoretical concept was also proven by measurements. Algorithms are proposed, how the temperature can be determined without any additional hardware. With the new method, temperature can be determined as an additional value and it can be used for self-awareness or temperature correction algorithms.