Bragg grating pressure cell and test method based on lever principle

Abstract

The invention discloses a Bragg grating pressure cell and a test method based on lever principle. The Bragg grating pressure cell mainly comprises a flat diaphragm, a shell, two strain transmitting devices, an optical fiber grating and two optical fiber leadout holes, wherein the flat diaphragm is arranged at the upper end of the shell; the two optical fiber leadout holes are formed in the lower end of the shell; the optical fiber grating is led in from one optical leadout hole and is led out from the other optical fiber leadout hole; the flat diaphragm is connected to the optical fiber grating by the strain transmitting devices; the two strain transmitting devices are symmetrically arranged below the flat diaphragm; and the upper surface of the strain transmitting devices are contacted with the flat diaphragm, and the lower surfaces of the strain transmitting devices are contacted with the optical fiber grating. The Bragg grating pressure cell and the test method based on the lever principle have the beneficial effects that the manufacturing technique is simple; the complete external manufacturing can be implemented; the product cost is reduced; the good expansibility is achieved; the measurement with different norms and ranges and different precisions can be realized by changing the arm lengths of the strain transmitting devices; and the high reliability and the good repeatability are achieved.

Description

technical field [0001] The invention relates to engineering measuring tools, in particular to a small-range, high-sensitivity Bragg grating pressure cell based on the lever principle and a testing method. Background technique [0002] Fiber Bragg Grating has been paid more and more attention due to its unique advantages such as strong anti-interference ability, good electrical insulation performance, corrosion resistance, small size, and low transmission loss. However, the pressure sensitivity coefficient of the bare grating is only 3pm / Mpa, which cannot meet the sensitivity requirements of ordinary pressure measurement. [0003] The patent (CN101206150A) discloses a fiber optic pressure sensor based on diaphragm deflection, including: a support cylinder, the lower end of which is a diaphragm for feeling pressure, and two round holes are opened on the side wall; a fiber grating, The fiber grating is installed in the support cylinder, and its two ends pass through two circul...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problem of low pressure sensitivity coefficient of the bare grating, the present invention proposes a Bragg grating pressure cell and a testing method based on the lever principle in combination with two types of grating sensitization, the planar diaphragm and the lever structure

Images