High Temperature Endurable Fiber Optic Accelerometer

Abstract

This paper presents a low frequency fiber optic accelerometer for application in high temperature environments of civil engineering structures. The reflection-based extrinsic fiber optic accelerometer developed in this study consists of a transmissive grating panel, reflective mirror, and two optical fiber collimators as the transceiver whose function can be maintained up to 130 ∘ C. The dynamic characteristics of the sensor probe were investigated and the correlation between the natural frequency of the sensor probe and temperature variation was described and discussed. Furthermore, high temperature simulation equipment was designed for the verification test setup of the developed accelerometer for high temperature. This study was limited to consideration of 130 ∘ C applied temperature to the proposed fiber optic accelerometer due to an operational temperature limitation of commercial optical fiber collimator. The sinusoidal low frequency accelerations measured from the developed fiber optic accelerometer at 130 ∘ C demonstrated good agreement with that of an MEMS accelerometer measured at room temperature. The developed fiber optic accelerometer can be used in frequency ranges below 5.1 Hz up to 130 ∘ C with a margin of error that is less than 10% and a high sensitivity of 0.18 (m/s 2 )/rad.

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“…Temperature is an important physical feature whose measurement is commonly used for fault or disease detection in industrial and medical fields. There are multiple techniques used for heat measurement, which include the use of sensors such as thermocouples to analyze stress in diesel motors [12] and to observe the behavior of a tooth exposed to different LED lights [13]; RTD (resistance temperature detector) is applied to support the process realized in solar dryers [14] or in distillation [15], as well as in civil engineering to monitor high temperature environments [16]; pyrometers are used for the control of temperature in spark plasma sintering [17]; coming to implement ultrasonic [18,19] and optical measuring techniques [20] to complement industrial processes in a non-intrusive way. Infrared (IR) sensing is a technology whose importance has grown in the last few years in multiple applications.…”