CN218298021U - F-P cavity infrared gas detector - Google Patents

Abstract

The utility model discloses an infrared gas detector in F-P chamber, including adjustable laser instrument, air chamber, FP chamber monochromator, light detector, data acquisition card, packaging shell A and packaging shell B, wherein, FP chamber monochromator chamber is apart from accurate regulation and control of accessible voltage. The gas detector utilizes the adjustable exciter and the controllable center wavelength F-P cavity structure to realize the continuous detection of multi-band and multi-component gas, and further, optical signals are converted into electric signals through the optical detector and are output, so that the real-time monitoring of the component change of the gas to be detected is realized. The detector has the advantages of high testing speed, accurate result and continuous batch detection, and effectively solves the problems of low detection sensitivity, large volume, low integration level and the like of multi-component gas.

Description

F-P cavity infrared gas detector

Technical Field

The utility model relates to a gaseous detection technical field especially relates to an infrared gas detector in F-P chamber.

Background

At present, in the industrial production link, environmental monitoring under extreme weather, academic research of some specific purposes and the like, an infrared spectrometer can be used for observation. During the implementation of specific projects, such as oil extraction, chemical processing, there are inevitably mixed many dangerous gases, such as carbon monoxide, carbon dioxide, hydrogen sulfide, etc. Hydrogen sulfide is toxic, flammable and explosive, but has obvious smelly eggs, and is easy to be found. Gases such as carbon monoxide are colorless, tasteless, flammable and explosive, and can cause serious potential safety hazards. The dangerous gas detector is used, so that the harmful gas leakage and poisoning accidents can be avoided, and the safety production is guaranteed.

In the prior art, the conventional optical infrared gas detector usually uses a fine structure such as a grating to realize spatial separation of spectra. The principle is similar to a prism, which spatially separates the incident light according to the wavelength, and then measures the intensity of the light with different wavelengths by using a light detector at a specific position in space to realize the measurement of the spectrum. However, such a method requires a large space, and the volume of the assembled product becomes large. In addition, conventional infrared gas detectors are susceptible to interference from heat sources, have poor infrared transmission, and are limited to detection and monitoring of only alkane combustible gases.

Chinese patent (CN 110146461A) discloses an infrared gas detector, which includes a frame, an infrared generator, a testing frame, a driving member and an infrared receiver, wherein the infrared generator emits infrared rays, which pass through a through hole reserved on the testing frame and are received by the infrared receiver, and a solid testing sheet replaces a calibration gas, without releasing the calibration gas to a calibration instrument. Although the detector overcomes the problem that the traditional infrared gas detector is easily interfered by the environment to a certain extent, the test precision of the detector cannot meet the monitoring requirement, and the detector adopts a test strip to replace standard gas for calibration, but the gases with similar components are difficult to be separated quickly and accurately, and the concentration and the proportion of the gases cannot be quantitatively given.

In summary, with the gradual development of the industry, especially for the projects containing important equipment such as petroleum and chemical industry, the requirements for monitoring and controlling toxic gases become more strict, and therefore, a gas detector which can overcome the environmental change, has strong durability, and can perform rapid, accurate and real-time monitoring is urgently needed in the market.

SUMMERY OF THE UTILITY MODEL

To the problems existing in the prior art, the utility model aims to provide an infrared gas detector of F-P chamber, this detector volume is light, and is portable easily to hold, utilizes adjustable exciter and controllable central wavelength F-P chamber structure to realize the detection to multicomponent gas. The detector has the advantages of high testing speed, accurate result and continuous batch detection, and effectively solves the problems of low detection sensitivity, large volume, low integration level and the like of multi-component gas.

In order to solve the technical problem, the utility model provides a F-P chamber infrared gas detector, include: the device comprises a tunable laser (1), an air chamber (2), an FP cavity monochromator (3), an optical detector (4), a data acquisition card (5), a packaging shell A (6) and a packaging shell B (7); the FP cavity monochromator (3), the optical detector (4) and the data acquisition card (5) are arranged inside the packaging shell A (6); an adjustable laser (1) is arranged in the packaging shell B (7); the center of the tunable laser (1) is on the same straight line with the centers of the FP cavity monochromator (3) and the optical detector (4); an air chamber (2) is arranged between the tunable laser (1) and the FP cavity monochromator (3); and openings are formed in one sides, facing the air chamber (2), of the packaging shell A (6) and the packaging shell B (7).

The utility model discloses utilize the synergistic effect in adjustable laser instrument and controllable center wavelength's F-P chamber, realized multiband, the gaseous serialization of multicomponent and detected. The adjustable laser (1) emits detection laser, the detection laser penetrates through gas to be detected in the cavity (2) and then enters the F-P cavity monochromator (3), the cavity distance of the F-P cavity monochromator (3) is adjusted, the gas is absorbed in a full-wave-band scanning detection range, spectrum information is collected through the optical detector (4), accurate testing of gas components to be detected is achieved, and finally accurate testing results of the gas components are input into the data acquisition card (5). Further, the utility model discloses the air chamber that sets up is for lining up the structure, can supply to wait to survey gaseous the passing through.

Preferably, the wavelength range of the emitted light of the tunable laser (1) is 200-2000 nm

As a preferred scheme, the FP cavity monochromator (3) comprises a piezoelectric ceramic, an upper reflecting mirror surface and a lower reflecting mirror surface.

As a preferred scheme, every two piezoelectric ceramics in the FP cavity monochromator are superposed to form a group of piezoelectric ceramics; the FP cavity monochromator (3) comprises two or more piezoelectric ceramic groups.

Preferably, the upper mirror surface and the lower mirror surface sandwich a piezoelectric ceramic group.

Preferably, the piezoelectric ceramic groups are parallel and equally spaced.

Preferably, the upper mirror surface and the lower mirror surface are adhered with a reflective layer.

As a preferable scheme, the center wavelength of the FP cavity monochromator (3) can be adjusted within the range of 0.9-14.5 μm.

The utility model discloses go up the speculum face and form the F-P chamber with the adnexed reflecting layer in speculum face surface down, the chamber in this F-P chamber is apart from accessible piezoceramics group to adjust, thereby reach the effect of the position of controllable regulation F-P chamber center wavelength lambda, light makes the transmission spectrum structure obviously be different from the incident spectrum through multiple reflection and transmission and coherent stack in the F-P intracavity, becomes the accurate spectrum of separating of transmitted light with continuous broad spectrum. Only a plurality of discrete quasi-single chromatographic lines are selected to participate in the incoherent superposition of the interference field; other spectral components are rejected without participating in the incoherent superposition of the interference field, and multi-beam interference thus has the effect of selecting wavelengths.

Preferably, the light detector (4) is a semiconductor substrate.

As a preferable mode, the semiconductor substrate is at least one of single crystal silicon, silicon oxide, and indium gallium arsenide.

Preferably, the data acquisition card (5) is a RAM memory.

The data acquisition card can not only realize the storage and reading of the obtained data, but also be connected with a computer to realize the real-time transmission of the data, thereby realizing the remote detection of the gas to be detected. Furthermore, a gas detection network can be formed by connecting a plurality of F-P cavity infrared gas detectors through a computer, so that remote detection and real-time monitoring of gas to be detected in different environments and different components are realized.

Preferably, the detector further comprises an image display device.

Preferably, the image display device is connected to the data acquisition card in a wired and/or wireless manner.

The tunable laser outputs detection light, which is provided to the F-P cavity monochromator after absorption of a probe gas.

The utility model provides an F-P chamber infrared gas detector theory of operation does:

when the wavelength of the detection light is coincident with the absorption wavelength of the gas, resonance absorption occurs, the absorption intensity of the resonance absorption is related to the concentration of the gas, and the concentration of the gas can be measured by measuring the absorption intensity of the light; when a white light source emitted by a laser penetrates through the measurement gas chamber, different gases can absorb light with corresponding characteristic wavelengths, and the light with different wavelengths can pass through by changing the piezoelectric ceramic to control the cavity length of the F-P cavity monochromator in front of the optical detector, so that different gases are measured.

Compared with the prior art, the utility model discloses a beneficial technological effect does:

1) The utility model provides an infrared gas detector has that the volume is light, and is portable easily to hold, and the test speed is fast, and the result is accurate and application scope advantage such as extensive, but continuous batch formula detects, has effectively solved that multicomponent gas detection sensitivity is low, bulky and the integration level hangs down the scheduling problem.

2) The utility model provides an infrared gas detector utilizes the synergism in the F-P chamber of adjustable laser instrument and controllable central wavelength, has realized that multiband, multicomponent are gaseous serialization detects, and is further, turns into the signal of telecommunication and exports with light signal through light detector, has realized the real time monitoring to the gas component change that awaits measuring.

3) The utility model provides an infrared gas detector detection range is wide, can be to the difference of the gaseous infrared characteristic absorption peak that awaits measuring, selects in succession in certain spectral range and transfers required wavelength, realizes that the continuity that multiple gas tunable in the detection range detects.

Drawings

Fig. 1 is a schematic structural view of an F-P cavity infrared gas detector provided in an embodiment of the present invention;

1-a tunable laser, 2-an air chamber, 3-an FP cavity monochromator, 4-an optical detector, 5-a data acquisition card, 6-a packaging shell A, 7-a packaging shell B;

FIG. 2 is a schematic structural view of an F-P cavity monochromator according to an embodiment of the present invention;

302. 303, 305 and 306-piezoceramic, 301-upper mirror surface, 304-lower mirror surface;

FIG. 3 is a scanning spectrum diagram of the F-P cavity infrared gas detection in the embodiment of the present invention;

fig. 4 is a flow chart of the F-P cavity infrared gas detection in the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

The following examples are given only to illustrate the technical solution of the present invention and not to limit it; although the present invention has been described in detail with reference to preferred embodiments, it should be understood by those skilled in the art that: modifications can still be made to the embodiments of the invention or equivalents may be substituted for some of the features; without departing from the spirit of the technical solution of the present invention, the present invention should be covered by the technical solution of the present invention.

Example 1

An F-P cavity infrared gas detector is shown in figure 1 and comprises a tunable laser (1), a gas chamber (2), an FP cavity monochromator (3), a light detector (4), a data acquisition card (5), a packaging shell A (6) and a packaging shell B (7).

Wherein the F-P cavity monochromator (3) comprises 4 piezoelectric ceramics (302, 303, 305 and 306), an upper reflecting mirror surface (301) and a lower reflecting mirror surface (304). Piezoelectric ceramics (302) and piezoelectric ceramics (303) form a piezoelectric ceramic group, piezoelectric ceramics (305) and piezoelectric ceramics (306) form a piezoelectric ceramic group, reflecting layers are plated on an upper reflecting mirror surface (301) and a lower reflecting mirror surface (304), and FP cavities are formed between the reflecting layers; the piezoelectric ceramic group is fixed between the upper and lower reflecting mirror surfaces. The height of the whole structure can be accurately adjusted by applying voltage to the piezoelectric ceramic group, so that the cavity distance h between the upper reflector surface and the lower reflector surface is continuously adjusted, the position of the central wavelength lambda of the F-P cavity is changed, and the spectrum information of the gas in the full-waveband scanning detection range is absorbed.

The method for detecting the gas components in the chemical engineering workshop environment comprises the following specific operation steps:

the method comprises the following steps: the tunable laser 1 emits a white light source with the wavelength of 0.9-1.7 μm;

step two: the white light source of 0.9 μm to 1.7 μm is absorbed by the gas passing through the gas cell 2;

step three: the F-P cavity monochromator 3 scans the white light absorbed by the gas by changing the central wavelength and displays a characteristic peak;

step four: the optical detector 4 converts the characteristic peak information into an electric signal and transmits the electric signal to the data integration card 5;

step five: the data integration card 5 is connected with a computer and uploads information.

After the test is started, scanning the gas at the speed of 1000 times/second, recording after the absorption peak of the gas component is found, and exporting the result after the characteristic peak of the gas component is stable, wherein the gas component and the absorption peak in the chemical workshop environment are shown in the table 1, and the accuracy rate of the test result is 99.5%.

TABLE 1 table of the component gas and absorption peak test results of a certain chemical plant environment

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Claims (7)

1. An infrared gas detector of F-P cavity, comprising: the device comprises a tunable laser (1), an air chamber (2), an FP cavity monochromator (3), an optical detector (4), a data acquisition card (5), a packaging shell A (6) and a packaging shell B (7); the FP cavity monochromator (3), the optical detector (4) and the data acquisition card (5) are arranged inside the packaging shell A (6); a tunable laser (1) is arranged in the packaging shell B (7); the center of the tunable laser (1) is on the same straight line with the centers of the FP cavity monochromator (3) and the optical detector (4); an air chamber (2) is arranged between the tunable laser (1) and the FP cavity monochromator (3); and openings are formed in one sides, facing the air chamber (2), of the packaging shell A (6) and the packaging shell B (7).

2. The infrared gas detector of claim 1, characterized in that: the wavelength range of the emitted light of the tunable laser (1) is 200-2000 nm.

3. The infrared gas detector of claim 1, characterized in that: the FP cavity monochromator (3) comprises piezoelectric ceramics, an upper reflecting mirror surface and a lower reflecting mirror surface; every two piezoelectric ceramics in the FP cavity monochromator are superposed to form a group of piezoelectric ceramic groups; the FP cavity monochromator (3) comprises two or more piezoelectric ceramic groups; a piezoelectric ceramic group is clamped between the upper reflecting mirror surface and the lower reflecting mirror surface; the piezoelectric ceramic groups are parallel and have equal intervals; and the surfaces of the upper reflecting mirror surface and the lower reflecting mirror surface are adhered with reflecting layers.

4. An F-P cavity infrared gas detector as claimed in claim 1 or 3, characterized in that: the tunable central wavelength range of the FP cavity monochromator (3) is 0.9-14.5 μm.

5. The infrared gas detector of claim 1, characterized in that: the photodetector (4) comprises a semiconductor substrate; the semiconductor substrate is at least one of monocrystalline silicon, silicon oxide and indium gallium arsenic.

6. The infrared gas detector of claim 1, characterized in that: the data acquisition card is an RAM memory.

7. The infrared gas detector of claim 1, characterized in that: the detector further comprises an image display device; the image display device is connected with the data acquisition card in a wired and/or wireless mode.

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