City Research Online

Abstract

In this paper, building on a design developed from an advanced mathematical model, a practical fiber optic sensor, which is an analog of the familiar 'hot-wire' wind velocity monitor, has been developed, as an intrinsically-safe sensor device for use on coal mining monitoring applications. The device response time, the dynamic measurement range, the sensitivity, the sensor probe surface heat transfer coefficient and the effect of the wind (gas) velocity has been investigated in the laboratory and in situ and results reported, enabling the mathematical model used in the design process to be validated. The underpinning optical fiber-based principle used is the shift in the center wavelength of a Fiber Bragg Grating which is cooled by the gas flowing over it and the device sensitivity found was determined to be ~1500pm per unit m/s wind velocity (in the range of 0 - 0.5 m/s), ~330pm per unit m/s in the range 0.5-2 m/s and ~50pm per unit m/s in the range of 2.0-4.5 m/s. In the 'proof of concept' tests carried out, it was found that the greater the surface dissipation factor of the sensor, the shorter was its response time. Further, the response time was seen to decrease as the wind velocity increased, showing a typical value of 6s, which is suitable for the mining applications envisaged.

Publication Type:	Article
Additional Information:	© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Subjects:	T Technology > TK Electrical engineering. Electronics Nuclear engineering
Departments:	School of Science & Technology > Engineering
SWORD Depositor:	Symplectic Administrator

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