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

Device and method for correcting secondary harmonic waveform of photoacoustic system and increasing precision

A second harmonic, photoacoustic technology, applied in measurement devices, color/spectral property measurement, material analysis by optical means, etc. Improve signal-to-noise ratio, low cost and simple operation

Active Publication Date: 2018-11-27
SHANDONG UNIV
View PDF9 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the above method needs to split the light of the laser, the signal amplitude will be significantly reduced, and the signal-to-noise ratio will be reduced, which is not conducive to signal detection.

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
  • Device and method for correcting secondary harmonic waveform of photoacoustic system and increasing precision
  • Device and method for correcting secondary harmonic waveform of photoacoustic system and increasing precision
  • Device and method for correcting secondary harmonic waveform of photoacoustic system and increasing precision

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] A device for correcting the second harmonic waveform of a photoacoustic system and improving accuracy, such as figure 1 As shown, it includes microcontroller a1, signal generator a2, adder a3, temperature control module a4, DFB laser a5, lock-in amplifier 6, preamplifier 7, microphone 8, photoacoustic pool 9, temperature control module b10, DFB laser b11, adder b12, single-chip microcomputer b13, signal generator b14 and computer 15, the output terminals of single-chip microcomputer a1 and signal generator a2 are respectively connected to the two input terminals of adder a4, the output of adder a3 and temperature control module a4 terminals are respectively connected to the DFB laser a5; the output terminals of the single chip microcomputer b13 and the signal generator b14 are respectively connected to the two input terminals of the adder b12, and the output terminals of the adder b12 and the temperature control module b10 are respectively connected to the DFB laser b11;...

Embodiment 2

[0032] A kind of method that utilizes above-mentioned device to work, the steps are as follows:

[0033] 1) Connect the above devices, turn on the single-chip microcomputer a2, the signal generator a3, the single-chip microcomputer b13, the signal generator b14 and the power supply of the computer 15, and inject the gas to be measured containing acetylene in the photoacoustic cell 9;

[0034] 2) Let the single-chip microcomputer a2 generate a sawtooth wave as a low-frequency scanning signal, and the single-chip microcomputer b13 generate an anti-sawtooth wave as a low-frequency scanning signal, and the signal generator a2 and the signal generator b14 generate a high-frequency modulation signal that is half the resonant frequency of the photoacoustic cell 9. After The adder a4 and the adder b12 add the scanning signal and the modulation signal as the driving signal, such as image 3 and 4 not;

[0035] 3) Turn on the power supply of the DFB laser a5, observe the position of t...

Embodiment 3

[0040] Same as Example 2, except that the gas to be measured is the gas to be measured containing water vapor, and the central wavelength of the DFB laser corresponds to the absorption peak of water vapor at 1368.597 nm.

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 relates to a device and a method for correcting a secondary harmonic waveform of a photoacoustic system and increasing precision and belongs to the field of gas sensing detection of optical fibers. The device comprises an DFB laser, a temperature control module, single chips, a signal generator, a photoacoustic cell, a microphone, a pre-amplifier and a lock-in amplifier; the two single chips are used for respectively generating a zigzag wave and an anti-aliasing wave as scanning signals; output ends of the single chips and signal generator are connected with an input end of a summator; the output end of the summator is connected with the DFB laser; the temperature control module is used for controlling the DFB laser to adjust the middle position of the gas absorption peak wavelength in a scanning signal cycle; the light emitted from the DFB laser enters into the photoacoustic cell; the microphone is placed on a microphone fixing position and is used for detecting the acoustic wave; the output end of the microphone is connected with the input end of the pre-amplifier; the output end of the pre-amplifier is connected with the input end of the lock-in amplifier; a computer is connected with the output end of the lock-in amplifier. A secondary harmonic wave signal with two symmetric lower peak valleys is acquired on the computer and the detecting precision is increased.

Description

technical field [0001] The invention relates to a technology for correcting a second harmonic signal, in particular to a device and method for correcting the second harmonic waveform of a photoacoustic system and improving accuracy, and belongs to the field of optical fiber gas sensing and detection. Background technique [0002] With the progress of society and the development of industry, the monitoring of various gases has become an increasingly prominent problem, which is increasingly affecting people's basic necessities of life. Optical fiber sensors based on photoacoustic spectroscopy have the advantages of high detection sensitivity and strong real-time performance. Photoacoustic spectroscopy is a detection technology developed based on the photoacoustic effect. For the detection of photoacoustic signals, wavelength modulation spectroscopy is a very effective method. Wavelength modulation spectroscopy technology is a combination of DFB laser wavelength modulation tec...

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
IPC IPC(8): G01N21/17G01N21/39G01N21/01
CPCG01N21/01G01N21/1702G01N21/39G01N2021/0112G01N2021/1704
Inventor 张秦端常军丛振华
Owner SHANDONG UNIV
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