Simulation of the Gas Flow Sensing Probe Based on Silver-Coated Fiber
Bragg Grating
Wenjun Zhu
1, 2,a
, Jia Cheng
2,3,b
, Zhenwei Huang
2,c
, Yan Zhou
1,2,d
and Dailiang Xie
1,e
1
China Jiliang University, Hangzhou 310018, China
2
Zhejiang Province Institute of Metrology, Hangzhou 310013, China
3
Zhejiang Provincial Center of Intellectual Property Service, Hangzhou 310012, China
a
zzzhuwenjun@126.com,
b
chengjiahz@163.com,
c
hzhuangzw@126.com,
d
zyevan@163.com,
e
dlxie_cjlu@163.com
Keywords: Fiber Bragg grating, Gas flow, Sensing probe, Simulation
Abstract. A novel gas flow sensing probe based on silver-coated Fiber Bragg Grating (FBG) is
proposed. A square hole was fabricated in the middle of a capillary stainless steel pipe. A
silver-coated FBG sensing probe was fixed up between the hole. The diameter of the silver-coated
FBG sensing probe is only 0.125 mm, with the PVC materials deposited around the surface of the
both ends with a diameter of 0.9 mm. Simulations on different packages of sensing probe were carried
out via Finite Element Method (FSM). Results of the simulations reveal that the sensing probe of the
capillary stainless steel pipe with a diameter of 3 mm and the square hole with a length of 12 mm can
provide the best performance.
Introduction
With the development of optical fiber sensing technology, lots of focus have been paid on optical
fiber sensor for its small size, high sensitivity, security, anti-electromagnetism interference and
multiplex characteristic [1].Several Fiber-optic flowmeters combined with optical fiber sensing
technology have been reported, such as: optical fiber turbine flow sensor [2], optical fiber Dopplor
velocity sensor [2], fiber Vortex flow-meter [3], inner cone flowmeter based on optic fiber grating [4]
and so on. Compared with traditional flow sensor, optical fiber sensor has following advantages: tight
structure, high sensitivity, good response rates, anti-electromagnetism interference and multiplex
characteristics [5]-[8]. A series of sensors combined with FBG and Long-Period fiber Gratings (LPG)
have been made steady progress. Gas flow measurenment is needed in industrial metrology of
large-scale diameter pipeline. However, the gas velocity is too small to obtain proper output signal
and linear property of flowmeter which is also limited by the local space and the length of straight
pipe in front and back, generally for the major pipelines in China [9].
Silicon is usually used as substrate materials in traditional micro thermal gas flow sensors. Thin
film resistors are put on a diaphragm which limite the thermal diffusion to be only transverse
diffusion in thin-film[10]. Resistors are also made into thin filaments and supported by brackets
which likes a cantilever beam [11]. Hot-film probe is generally produced by depositing thin platinum
film or nickel film on wedged or cylindrical thermal insulation substrate(usually quartz). Several
resistors which are integrated in one ceramic substrate can be used to make new kind of probes[12].
Hot-wire probe is soldered on two wishbones which can maintains fixity by combining connector
lines with plug bar together. There are some other popular gas flow sensors which are based on the
same thermal flow sensing mechanism. They are made of metal oxide whose main component is
SnO
2
(tin oxide). In recent years, researchers launch out into a series of experiments to research the
influences which are caused by different sensor substrate material, structure or size by using finite
element softwares[13]. This method provides a better way for how to design and deside the better size
or structure of the sensing probes[14].
Applied Mechanics and Materials Vols. 321-324 (2013) pp 286-292
© (2013) Trans Tech Publications, Switzerland
doi:10.4028/www.scientific.net/AMM.321-324.286
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP,
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