Development and Evaluation of Temperature Sensing Smart Skin for High-Temperature Measurements in Pipes

Abstract

We designed a temperature sensing smart skin with a composite insulation layer for high-temperature monitoring of pipelines and engine combustion chamber walls, and proposed a thin/thick film hybrid integrated manufacturing process to improve the high temperature stability of the sensor. A PtRh/Pt thick-film thermocouple was installed on an ultra-thin nickel-based alloy substrate by screen printing and then fixed on a pipe inner wall by spot welding. The morphology of the prepared composite insulation layer was studied by scanning electron microscopy, and its insulation resistance was tested at high temperatures, verifying its high insulation performance. In addition, the output voltage has high linearity in the temperature range of 25–1000 °C, and the prepared thermocouple shows consistency and reusability with an average Seebeck coefficient of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$9.016 ~ \mu \text{V}$ </tex-math></inline-formula> /°C. Upon testing the thermocouple at 1100 °C for 10 hours, the peak voltage output was 10.094 mV and the average output voltage was 10.051 mV. Experiments show that the thick-film thermocouple operates stably at high temperatures and can work at 1400 °C in a short time.