Abstract
High temperature sensors capable of operating in harsh environments are needed in order to prevent disasters caused by structural or system functional failures due to increasing temperatures. Most existing temperature sensors do not satisfy the needs because they require either physical contact or a battery power supply for signal communication, and furthermore, neither of them can withstand high temperatures nor rotating applications. This paper presents a novel passive wireless temperature sensor, suitable for working in harsh environments for high temperature rotating component monitoring. A completely passive LC resonant telemetry scheme, relying on a frequency variation output, which has been applied successfully in pressure, humidity and chemical measurement, is integrated with a unique high-k temperature sensitive ceramic material, in order to measure the temperatures without contacts, active elements, or power supplies within the sensor. In this paper, the high temperature sensor design and performance analysis are conducted based on mechanical and electrical modeling, in order to maximize the sensing distance, the Q factor and the sensitivity. In the end, the sensor prototype is fabricated and calibrated successfully up to 235°C, so that the concept of temperature sensing through passive wireless communication is proved.
Highlights
IntroductionIn order to prevent disasters caused by structural failure due to high temperatures, sensors capable of measuring high temperatures in harsh environments are needed, for example, for high temperature monitoring of heat resistant tiles of the space shuttle, high temperature testing of rotating bearings in the aircraft engine, and qualification testing of disc brakes, jet engine dynamics and high-speed shaft rotations [1,2,3,4]
Existing high temperature sensing devices are briefly introduced which include high temperature thermocouples, high temperature optical sensors, high temperature surface acoustic sensors (SAW),as well as the RF powered LC sensors
The signal outputting from a thermocouple is weak and can be affected by common mode noises. They drift significantly under high temperature environments during long-term operation [5]. They have a limited life of only a few days because of their susceptibility to attack from corrosive chemicals
Summary
In order to prevent disasters caused by structural failure due to high temperatures, sensors capable of measuring high temperatures in harsh environments are needed, for example, for high temperature monitoring of heat resistant tiles of the space shuttle, high temperature testing of rotating bearings in the aircraft engine, and qualification testing of disc brakes, jet engine dynamics and high-speed shaft rotations [1,2,3,4]. A battery is usually the element that limits the sensor lifetime and the operating temperature range, and “virtual batteries” powered by RF radiation is a promising alternative to chemical batteries Because their small size and stable characterization, the RF powered LC sensors are suitable for transmitting high energy for short distances as required in harsh medical and industrial environments, where, for instance, high temperature pressure sensors [11,12,13], high temperature chemical sensors [14], and humidity sensors [15] etc.
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
