A Fiber Bragg Grating Pressure Sensor

Abstract

The invention relates to a fiber grating pressure sensor, which comprises an outer protection tube, a pressure measuring fiber grating, an elastic substrate and an elastic diaphragm. The elastic diaphragm is arranged in the outer protection tube and separates the outer protection tube to form a measured fluid cavity and a reference fluid cavity. , the measured fluid cavity is connected to the measured fluid, the reference fluid cavity is connected to the atmosphere, the elastic substrate is set in the reference fluid cavity, and is fixedly connected with the elastic diaphragm, and the pressure sensor also includes a temperature-measuring fiber grating, which is connected to the temperature-measuring fiber grating The pressure fiber grating is connected in series on the same optical fiber, the fiber passes through the elastic substrate and the elastic diaphragm, the pressure measurement fiber grating is located in the reference fluid cavity, and the two ends of the pressure measurement fiber grating are respectively fixed on the elastic substrate and the elastic diaphragm Above, the temperature measuring fiber grating is located in the measured fluid chamber, one end of the temperature measuring fiber grating is connected to the pressure measuring fiber grating, and the other end is a free end. Compared with the prior art, the present invention has the advantage of high measurement accuracy.

Description

technical field [0001] The invention relates to a pressure sensor, in particular to an optical fiber grating pressure sensor with a temperature measuring function. Background technique [0002] Fluid pressure sensor is a sensor with a wide range of uses, such as bridges, dams, hydrology, tunnels, chemical industry, meteorology, slopes, etc., commonly used sensing elements for detection or monitoring. Among the various existing detection schemes, due to temperature interference, electromagnetic interference, safety, long-distance transmission, service life, reliability and other reasons, it is impossible to solve the pressure detection problems of this series of industries well. [0003] The fiber grating pressure sensor can solve the problems caused by temperature interference, electromagnetic interference, safety, long-distance transmission, service life, reliability, etc. in the current detection scheme. However, the existing fiber grating pressure sensors generally do no...

AI Technical Summary

Problems solved by technology

Among the various existing detection schemes, due to temperature interference, electromagnetic interference, safety, long-distance transmission, service life, reliability and other reasons, it is impossible to solve the pressure detection problems of this series of industries well.

[0003] The fiber grating pressure sensor can solve the problems caused by temperature interference, electromagnetic interference, safety, long-distance transmission, service life, reliability, etc. in the current detection scheme.

However, the existing fiber grating pressure sensors generally do not have the function of temperature measurement, because the fiber grating has the characteristic of temperature and strain cross sensitivity, so temperature compensation must be carried out; secondly, in the packaging structure of the existing fiber grating pressure sensor, the elastic diaphragm Or the elastic substrate is directly rigidly connected to the outer protection tube, and the force of the outer protection tube will interfere with the pressure measurement fiber grating, thereby affecting the measurement accuracy; in addition, the reference fluid chamber on the side of the elastic diaphragm in the existing products is not connected to the atmosphere. Does not effectively eliminate the effects of residual gas pressure inside the sensor or changes in external atmospheric pressure

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