SU1372263A1 - Fibre-optical phase pressure transducer - Google Patents

Abstract

The invention relates to fiber optics and makes it possible to increase the sensitivity of the sensor to radial pressure. The radiation from source 1 is directed by splitter 2 along measuring fiber-optic channels 3 and 4. The fiber of one of the channels is made with Young's modulus values, coefficient. Poisson and cross-sectional areas of the cores and shells, which meet certain requirements. Due to this implementation, the fiber acquires a negative phase sensitivity to radial pressure. The impact on the radial pressure sensor causes a phase shift of the radiation in channels 3 and 4 in opposite directions. The adder 6, in which the interference of the radiation emitted from channels 3 and 4 occurs, and the recorder 7 selects a signal proportional to the pressure value from the interference pattern. 1 il. with f (l

Description

Ichobrcking is detected in phasg) G (1m) (interferonmetryCIMJNocommunication-optical sensors Pelichin v can be used to measure radial pressure,

Objective invents - raising radial pressure sensitivity

The drawing shows a diagram of the sensor.

The sensor contains a coherent radiation source 1, a radiation splitter 2, two measuring fiber optic channels 3 and A, in one of which a modulator 5 is installed, an adder 6 of radiation, and a phase difference recorder 7.

The fiber in one of the channels (for example, 4) is made with core and shell parameters that meet the requirement

2SjVj - 23g V, Ej

(P. 4- C) E, - 2 V, p,,

where S and Sj are the cross-sectional areas of the core and shell, respectively; V, n V, - Poisson's ratios

cores and shells; E and EJ are Young's modules;

p, is the index of prechochen

zhygy; C, and Cj are photoelastic constants

core material.

When v1 (11 vol. 1: reduced respectively en fiber channel 4 acquires the property of negative phase sensitivity to radial pressure. Fiber D channel 3 is of the usual type, Toya, with positive phase sensitivity to radial pressure. The device works as follows.

Radiation and :, source 1 enters through splitter 2 into channels 3 and 4,

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s

722ВЗ

passage to the canal. 3 through modulator 3 (; iJiH implementation of the heterodyne mode). Under the action of the radial pressure of the radiation phase in channels 3 and 4 are shifted at selected parameters of the fibers in opposite directions, which provides an increased sensitivity of the sensor. From the outputs of channels 3 Q and 4, the radiation arrives at the adder 6, where the radiation interference occurs, and then to the recorder 7. The adder 6 and the recorder 7 transmit the signal 15 proportional to the phase difference, i.e. pressure value.

Claims (2)

Invention Formula 20 Fiber optic phase pressure sensor containing a coherent radiation source, a radiation splitter, two fiber optic channels with a modulator in one of them, 25 a radiation adder and a phase difference recorder, wherein the fiber optic channels are made of the same optical length, which is so as to increase 30 radial pressure sensitivity, both channels are made measuring and the optical fiber of one channel is made with the Yung modulus value of E core, E shell, Poisson’s ratio V core, and Vj plates and cross sections of SRI S core, and Sj shell meet your requirements 35 40 2J, V, E, - 2.S, V, J,  5 7Е7 йТКТ Е, Cj) (С, h - Cj) Е, - 2 V, n,, 45. Where n, is the index of the core; C, and Cj are the photoelastic constants of the core material.