High temperature measurement on static and rotating machinery

Temperature provides a critical piece of information about machine health condition. The objective of this project is to design a transducer that can sense temperatures in high temperature environments (>1000C). Techniques for measuring temperature include wire thermocouples, ultrasonic waves, and thin film thermocouples. Ultrasonic wave measurement operates on the principle that a wave's speed changes due to the material properties, which are in turn affected by temperature. Ultrasonic surface waves involve exciting the structure with high frequency wave (>100KHz), and measuring the time of flight. The main challenges for measuring at high temperature are: (1) low signal to noise ratio, (2) the propagation loss of the transmitted signal, and (3) the transducer nonlinearity and sensor accuracy and reliability.
In order to detect a degree change in temperature using the proposed guided wave mechanism, a very high sampling rate (GHz) is required to detect the reflected wave. With the recent advent of improved high-temperature electronics, and transducers in particular, it is now possible to detect guided waves in the GHz frequency range. Such a frequency is required to match the one-degree-level resolution delivered by existing thermocouple solutions, while improving the reliability and maintainability of the temperature sensing system as a whole.
The proposed project is aligned with ECS strategies and covers the sensing part of C-IoT.