Self-compensating displacement sensor based on hydramatic structured transducer and fiber Bragg grating

Shimeng Chen,Xiuxin Liu,Yun Liu,Yang Zhang,Wei Peng

doi:10.1007/s13320-015-0278-4

Shimeng Chen, Xiuxin Liu + Show 3 more

Open Access

https://doi.org/10.1007/s13320-015-0278-4

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Abstract

An optical fiber displacement sensor with a large measuring range for simultaneous displacement and temperature measurement is presented in this paper. We developed a specific transducer based on the piston and hydraumatic structure to realize a large displacement measurement, which combined the large measuring range and high precision into a single sensor system. The spectrum showed two reflection peaks used to compensate for cross-sensitivity in the displacement detection. This displacement sensor can linearly work in a large measuring displacement range greater than 45 mm with a high sensitivity of 0.036 nm/mm. The sensor we reported can be developed for real-time displacement monitoring in many industrial environments such as the mechanical shape or liquid level monitoring.

Highlights

Optical fiber sensors have emerged as common sensing elements for temperature [1], strain [2], refractive index (RI) [3], force [4], and other parameters measurement, because of their features of anti-electromagnetic interference, corrosion resistance, compactness, lightweight, and high sensitivity, etc. [5, 6]
Different types of fiber displacement sensors were demonstrated in the fields of the interferometry [7,8,9], intensity modulation method [10, 11], and wavelength modulation method based on the fiber Bragg grating (FBG) [12,13,14]
We experimentally demonstrated a self-compensating displacement sensor with the large measuring range. Because it combined the hydramatic structured transducer and FBG into a single sensor system, it possessed the advantages of both types

Summary

Introduction

Optical fiber sensors have emerged as common sensing elements for temperature [1], strain [2], refractive index (RI) [3], force [4], and other parameters measurement, because of their features of anti-electromagnetic interference, corrosion resistance, compactness, lightweight, and high sensitivity, etc. [5, 6]. Different types of fiber displacement sensors were demonstrated in the fields of the interferometry [7,8,9], intensity modulation method [10, 11], and wavelength modulation method based on the fiber Bragg grating (FBG) [12,13,14]. The strain and temperature cross-sensitivity problem could influence the experimental result. A type of improved FBG sensors was reported [13] It could simultaneously measure displacement and temperature. The problems of low sensitivity and cross-sensitivity have been solved, most of those displacement sensors are limited by small measuring. The sensor we designed featured a large measuring range, high sensitivity, favorable durability and could avoid the cross-sensitivity problem

Principle and system construction

Experiments and discussion

Conclusions