Abstract
Abstract. A temperature sensor based on piezoelectric single crystals allowing stable operation in harsh environments such as extreme temperatures and highly reducing or oxidizing atmospheres is presented. The temperature dependence of the mechanical stiffness of thickness shear mode resonators is used to determine temperature changes. The sensor is based on catangasite (Ca3TaGa3Si2O14 – CTGS), a member of a langasite crystal family. CTGS exhibits an ordered crystal structure and low acoustic losses, even at 1000 ∘C. The resonance frequency and quality factor of unhoused and of housed CTGS resonators are measured up to about 1030 ∘C. A temperature coefficient of the resonance frequency of about 200 Hz K−1 for a 5 MHz device is found and enables determination of temperature changes as small as 0.04 K. Housed CTGS resonators do not show any significant change in the resonance behavior during a 30 d, long-term test at 711 ∘C.
Highlights
Piezoelectric devices based on high-temperature, stable single crystals are of increasing interest due to a wide range of potential applications, such as actuators or temperature sensors
This paper focuses on the characterization of temperature sensors based on CTGS resonators operated in the thickness shear mode (TSM)
A piezoelectric temperature sensor based on housed CTGS thickness shear mode resonators is presented
Summary
Piezoelectric devices based on high-temperature, stable single crystals are of increasing interest due to a wide range of potential applications, such as actuators or temperature sensors. Conventional temperature sensing devices based, e.g., on thermocouples provide great absolute accuracy; their low signal in the range of several millivolts is much more sensitive to electromagnetic noise than, e.g., a measurement of resonance frequency of a piezoelectric sensor. This paper focuses on the characterization of temperature sensors based on CTGS resonators operated in the thickness shear mode (TSM). This mode enables the use of robust and high-temperature stable electrodes which are the precondition for the experiments presented in the following. The response time for temperature changes and the long-term stability of the measured properties are determined and discussed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
