Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

TDLAS (Tunable Diode Laser Absorption Spectroscopy) gas detection method and system

A gas detection and gas chamber technology, applied in the optical field, can solve the problems of large errors, deviations, and inability to ensure consistency in the concentration values ​​of ammonia and nitrogen, and achieve the effect of preventing gas leak detection and reducing errors

Active Publication Date: 2014-03-19
BEIJING SDL TECH
View PDF5 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, it is impossible to guarantee that the gas layer irradiated by the laser is consistent with the gas layer irradiated at the calibrated level, so that the measured results will have obvious deviations
like figure 2 As shown, when the placement of the gas chamber is deflected at a certain angle from the calibrated level (from L to L1), the optical path exposed to ammonia is only in the DP segment, and DP<MN, so the measured ammonia and nitrogen The concentration value error is large

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • TDLAS (Tunable Diode Laser Absorption Spectroscopy) gas detection method and system
  • TDLAS (Tunable Diode Laser Absorption Spectroscopy) gas detection method and system
  • TDLAS (Tunable Diode Laser Absorption Spectroscopy) gas detection method and system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0072] image 3 It is a flow chart of Embodiment 1 of a TDLAS gas detection method of the present invention, and the method includes:

[0073] Step 301: The line laser light emitted by the semiconductor laser is incident on the transmission fiber.

[0074] The light output by the laser has good collimation and small divergence angle, which can be regarded as a line laser.

[0075] Step 302: The line laser emitted from the transmission fiber is incident on the total reflection mirror.

[0076] The line laser output by the laser is transmitted to the total reflection mirror through the transmission fiber. Generally, the line laser output by the laser is transmitted horizontally. In order to make the line laser incident into the vertically placed gas chamber, a total reflection mirror is used to change the transmission direction of the line laser.

[0077] Step 303: The total reflection mirror reflects the line laser light and then enters the vertically placed air chamber.

...

Embodiment approach

[0084] The first possible implementation is as Figure 4 Shown:

[0085] The line laser incident into the vertically placed gas chamber is reflected once by the first total reflection mirror and then emerges from the line laser incident surface.

[0086] For example: Assume that a vertically placed gas chamber is filled with two mixed gases of ammonia and nitrogen with different specific gravity. The specific gravity of ammonia gas is smaller than that of nitrogen gas. The two gases are layered in the vertically placed gas chamber, and the ammonia gas is in the upper layer. , nitrogen in the lower layer. The line laser is incident into the vertically placed air chamber, reflected by the first lens group set in the air chamber, and then emitted from the incident surface of the line laser. The line laser first irradiates ammonia and nitrogen in the vertically placed gas chamber in sequence, and then the line laser reflected by the first total reflection mirror irradiates nitro...

Embodiment 2

[0095] Figure 6 It is a flow chart of Embodiment 2 of a TDLAS gas detection method of the present invention. Compared with Embodiment 1, in Embodiment 2, the linear laser beam is expanded into a strip laser for detection, and the method includes:

[0096] Step 601: The line laser emitted by the semiconductor laser is incident on the transmission fiber.

[0097] Step 602: The line laser light emitted from the transmission fiber is incident on the total reflection mirror.

[0098] Step 601 and step 602 are similar to the first embodiment, refer to the description of the first embodiment, and will not repeat them here.

[0099] Step 603: The total reflection mirror reflects the line laser light and then enters the second lens group to expand the beam into a strip-shaped laser light.

[0100] The second lens group expands the line laser beam into a strip laser, such as Figure 7 As shown, the optical path diagram of beam expansion is as follows:

[0101] The total reflection ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides a TDLAS (Tunable Diode Laser Absorption Spectroscopy) gas detection method and system. The method comprises the following steps that line laser emitted from a semiconductor laser enters a transmission optical fiber; line laser emitted from the transmission optical fiber enters a holophote; the line laser is reflected by the holophote and subsequently enters a vertically arranged air chamber; the line laser entering the air chamber is reflected by a first lens group and is subsequently emitted out from an incident plane of the line laser; an analysis device is used for receiving and detecting the line laser emitted from the vertically arranged air chamber. Because of the different specific gravities of various gases in a mixture gas, the gases are layered in the vertically arranged air chamber, after entering the vertically arranged air chamber, the laser is reflected by the first lens group and is subsequently emitted out from the incident plane of the laser, and the laser can be radiated to each layer of the gas in the vertically arranged air chamber, so that the situation of gas detection omission is prevented, and the error of mixture gas detection is reduced.

Description

technical field [0001] The invention relates to the field of optical technology, in particular to a TDLAS gas detection method and system. Background technique [0002] Tunable Diode Laser Absorption Spectroscopy (TDLAS) analysis method is a commonly used gas analysis method. It mainly uses the tunable and narrow linewidth characteristics of semiconductor lasers to select a specific absorption line of the gas to be measured. The measurement of the spectral line can eliminate the interference of the spectrum of other gases, and realize the rapid online detection of the concentration of the gas to be measured. [0003] TDLAS technology is a high-resolution spectral absorption technology. The light intensity attenuation of the laser passing through the measured gas can be expressed by the Lambert-Beer law formula (1): [0004] A=lg(1 / T)=Kbc (1) [0005] Among them, A is the absorbance, T is the transmittance, which is the ratio of the projected light intensity to the incident...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G01N21/39
Inventor 梁学军
Owner BEIJING SDL TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com