CN85201064U - Low noise photoacoustic detector - Google Patents
Low noise photoacoustic detector Download PDFInfo
- Publication number
- CN85201064U CN85201064U CN198585201064U CN85201064U CN85201064U CN 85201064 U CN85201064 U CN 85201064U CN 198585201064 U CN198585201064 U CN 198585201064U CN 85201064 U CN85201064 U CN 85201064U CN 85201064 U CN85201064 U CN 85201064U
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- detector
- noise
- window
- optoacoustic
- utility
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- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims abstract description 22
- 239000011780 sodium chloride Substances 0.000 claims abstract description 11
- 239000013078 crystal Substances 0.000 claims abstract description 7
- 230000001681 protective effect Effects 0.000 claims abstract description 6
- 229910001220 stainless steel Inorganic materials 0.000 claims 1
- 239000010935 stainless steel Substances 0.000 claims 1
- 238000005516 engineering process Methods 0.000 abstract description 8
- 230000003287 optical effect Effects 0.000 abstract description 4
- 230000035945 sensitivity Effects 0.000 abstract description 4
- 239000000126 substance Substances 0.000 abstract description 3
- 230000002411 adverse Effects 0.000 abstract description 2
- 238000004458 analytical method Methods 0.000 abstract description 2
- 238000004891 communication Methods 0.000 abstract description 2
- 238000001307 laser spectroscopy Methods 0.000 abstract description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 2
- 238000012360 testing method Methods 0.000 abstract description 2
- 230000007613 environmental effect Effects 0.000 abstract 2
- 239000000470 constituent Substances 0.000 abstract 1
- 238000001035 drying Methods 0.000 abstract 1
- 230000003584 silencer Effects 0.000 abstract 1
- 238000010183 spectrum analysis Methods 0.000 abstract 1
- 238000001514 detection method Methods 0.000 description 7
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 6
- 238000006748 scratching Methods 0.000 description 6
- 230000002393 scratching effect Effects 0.000 description 6
- 229910002092 carbon dioxide Inorganic materials 0.000 description 3
- 239000001569 carbon dioxide Substances 0.000 description 3
- 239000002274 desiccant Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000003071 parasitic effect Effects 0.000 description 3
- 229910018503 SF6 Inorganic materials 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000011324 bead Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000008030 elimination Effects 0.000 description 2
- 238000003379 elimination reaction Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- VIKNJXKGJWUCNN-XGXHKTLJSA-N norethisterone Chemical compound O=C1CC[C@@H]2[C@H]3CC[C@](C)([C@](CC4)(O)C#C)[C@@H]4[C@@H]3CCC2=C1 VIKNJXKGJWUCNN-XGXHKTLJSA-N 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- SFZCNBIFKDRMGX-UHFFFAOYSA-N sulfur hexafluoride Chemical compound FS(F)(F)(F)(F)F SFZCNBIFKDRMGX-UHFFFAOYSA-N 0.000 description 2
- 229960000909 sulfur hexafluoride Drugs 0.000 description 2
- 229910001369 Brass Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 230000004313 glare Effects 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 230000010358 mechanical oscillation Effects 0.000 description 1
- 238000004867 photoacoustic spectroscopy Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000003566 sealing material Substances 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/1702—Systems in which incident light is modified in accordance with the properties of the material investigated with opto-acoustic detection, e.g. for gases or analysing solids
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/1702—Systems in which incident light is modified in accordance with the properties of the material investigated with opto-acoustic detection, e.g. for gases or analysing solids
- G01N2021/1704—Systems in which incident light is modified in accordance with the properties of the material investigated with opto-acoustic detection, e.g. for gases or analysing solids in gases
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The utility model discloses a low noise photoacoustic detector, and belongs to the manufacturing technology of optical testing instruments. The detector mainly solves the problem of interference from the detector window noise and the environmental noise, and is characterized in that a window protective device and a fully enclosed out appearance are composed of a sodium chloride single crystal plate window, a deep hole light column, a drying silencer, an airflow channel, which has the functions of moisture protection, environmental noise protection and electromagnetic interference protection. The detector has the advantages of low detector noise and high sensitivity, which can be used in adverse environment. The utility model can be suitable for laser spectroscopy, chemical kinetics, spectral analysis of isotopes, gas micro constituent analysis, space communication, etc.
Description
The utility model belongs to the optical testing instrument manufacturing technology.
Prior art: the utility model is based on traditional optoacoustic detection technology and principle.Existing optoacoustic detector generally is made of photoacoustic cell, electret, detection window, outer cover, extraction valve, binding post.Optoacoustic detector is to utilize medium to absorb the optical detection device that converts electric signal output with the caused pressure pulse of light pulse of audio frequency modulation to.The overriding noise of this optoacoustic detector has: the thermonoise of detector window and optoacoustic pool wall, neighbourhood noise (comprising parasitic light, extraneous acoustic vibration, mechanical vibration, thermal fluctuation), external electromagnetic is dried scratches, electret noise etc.The recent development of optoacoustic detection technology at present, has following reported in literature:
（1）Yah－Han Pao，Cptoacoustic Spectroscopy and Detection。（1977）
（2）Lars－Goran Rosengren，Applied Optics，14（8），1960－1976，（1975）
（3）Gary A，West，Joseph J.Barratt，Donald Siebert and K.Virupaksha.Reddy，Rev.Sci.Instrum，54（7），797－817，（1983）
（4）D.R.Wake and N.M.Amer，Appl Phys Lett，34，379，（1979）
These documents have been made detailed description to existing optoacoustic detection technology and principle, but to dried effective ways and the technology that does not provide concrete elimination so far of scratching of topmost window noise and environment wherein, therefore existing optoacoustic detector window noise ratio is more serious, anti-neighbourhood noise ability, be not suitable for than using in the rugged surroundings, thereby limited the usable range of existing optoacoustic detector.
The utility model purpose: the purpose of this utility model is exactly in order to eliminate optoacoustic detector window noise and optoacoustic pool wall noise, neighbourhood noise (comprising parasitic light, extraneous acoustic vibration, mechanical vibration and thermal fluctuation noise), reduce the electret background noise, shield that worn-out external electromagnetic is dried scratches, improve optoacoustic detector signal to noise ratio (S/N ratio), sensitivity and the dried ability of scratching of anti-neighbourhood noise, enlarge the usable range of optoacoustic detector.
The utility model content: according to the optoacoustic detector (accompanying drawing 1,2) that the utility model provides, it is by sodium chloride (NaCl) single-chip window (1), Bu Rust steel radome (7), electric capacity electret (8), photoacoustic cell (9), vacuum valve (10), Q
9Socket (6), (11) and window protective device (accompanying drawing 3) are formed, and general structure is to neighbourhood noise and the dried full-shield type of scratching of electromagnetism.Detector two-layerly is made of inside and outside, internal layer is 10 * 28 millimeters T-shape brass tubes of φ photoacoustic cell (9), photoacoustic cell separates to reduce extraneous mechanical vibration and thermonoise with vacuum rubber circle (5) that has the right angle aperture and radome (7), and this right angle aperture is ventilated in addition and prevented the acoustic resonance effect.The photoacoustic cell inwall must polish (at least
10) to reduce the wall noise.An electric capacity electret (8) is adorned in the top, pond, three leads of electret, and two root beads are wherein received Q
9On the socket (11), another root bead is received Q
9On the socket (6), Q
9Socket (6), (11) with being laser-welded on the radome (7), are in order to guarantee that the radome inner member is not subjected to fire damage with laser bonding respectively after vacuum seal (accompanying drawing 4).Q
9Socket (11) directly is connected with special-purpose ground wire, has played and has scratched fabulous shielding action to electromagnetism is dried.The detector skin is a not Rust steel cavity (7) of 50 millimeters of diameter phi, cavity is formed by two sections, in aggregates with laser bonding, the cavity both ends of the surface have circular window, two sodium chloride single crystal sheets (1) are bonded in the window place with normal temperature vacuum seal material, and this sodium chloride single crystal sheet centering infrared band laser absorption coefficient is minimum.Cavity side laser bonding vacuum valve (10).Entire device is the high vacuum seal body.
(accompanying drawing 3) is the window protective device, and this protective device is center of the present utility model, and it comprises sodium chloride single crystal sheet window (1), deep hole light hurdle (2), dry sound suppressor (3) gas channel (4).Dry sound suppressor (3) wherein is a porous cavity, can dismantle, and it is by Porous Base (14), and the deep hole light hurdle sidewall (18) of porous and screwed circular cowling (16) are formed.Cavity wall blocks preventing in the chamber material to window pollution with silk (or other material), filling fine particle shape drying agent in the chamber, and this structure has dry and noise elimination effect, can prevent sodium chloride window deliquescence, shields extraneous acoustic vibration noise.Deep hole light hurdle (2) is used for shielding worn-out dried the scratching with electromagnetic wave is dried of extraneous parasitic light and scratches, and it is made of the cylindrical deep hole (19) of 6 * 20 millimeters of φ, is connected with dry sound suppressor (3) with sunk screw (13), and it can shield from 0 dried the scratching of electromagnetism to the microwave section.Breeder tube (4) is communicated with cavity (20) before deep hole (19), the window; blanket gas slowly flows through (20), (19) by aperture (4); this air-flow protection mechanism can not only prevent sodium chloride window deliquescence; and can constantly take away optical channel and near the waste heat of window; eliminate near the thermal fluctuation noise of window; this protection air-flow has also guaranteed the drying agent in the dry sound suppressor, and drying agent is prolonged serviceable life, and this air-flow protection against the tide and cooling technology are applicable to multiple light path system.
The optoacoustic detector that the utility model provides can be used for fields such as laser spectroscopy, Chemical Kinetics, the spectro chemical analysis of isotopes, environmental pollution measurement, space communication.
The optoacoustic detector that provides with the utility model has carried out no Doppler's spectrum experiment (accompanying drawing 8) and noise measurement, fills 40 milli torr sulfur hexafluoride (SF in the detector
6) time, background noise 40 microvolts (accompanying drawing 5,200 microvolts among the figure/lattice), incident laser (carbon dioxide P
16Branch line) during power 32 milliwatts, 1 millivolt of output voltage (accompanying drawing 6,500 microvolts among the figure/lattice), this moment signal to noise ratio (S/N ratio) 25, sensitivity 31.25 microvolts/milliwatt, incident laser (carbon dioxide P
16Branch line) during power 246 milliwatts, 250 millivolts of lock-in amplifier output voltages (accompanying drawing 7,100 millivolts/lattice among the figure amplify 40 decibels), this moment signal to noise ratio (S/N ratio) 62.5, sensitivity 10 microvolts/milliwatt.(accompanying drawing 8) is when filling 60 milli torr sulfur hexafluoride gas in the detector, carbon dioxide laser P
16No Doppler's optoacoustic spectroscopy figure of branch line.
The optoacoustic detector that the utility model provides compare with existing traditional optoacoustic detection technology have noise low, highly sensitive, to veiling glare, extraneous acoustic vibration, mechanical oscillation, the dried advantage of scratching fabulous shielding action of electromagnetism, can in than adverse circumstances, use.
Make the optoacoustic detector that the utility model provides, pay special attention to all elements are made cleaning in advance, keep high cleanliness, assembling will be carried out in hothouse, guarantees that it is to make successful key that detector has condition of high vacuum degree.
Description of drawings is as follows:
Accompanying drawing 1: the optoacoustic detector general structure longitudinal sectional drawing that provides according to the utility model
Accompanying drawing 2: the optoacoustic detector general structure transverse cross-sectional view that provides according to the utility model
Accompanying drawing 3: sodium chloride single crystal sheet window protective device sectional view
Accompanying drawing 4:Q
9The socket sectional view, (22) are vacuum sealing material among the figure
Accompanying drawing 5: the optoacoustic detector background noise figure that the utility model provides
Accompanying drawing 6: amplitude modulated light acoustic output signal during incident laser power 32 milliwatts
Accompanying drawing 7: modulating light acoustic output signal during incident laser power 246 milliwatts
Accompanying drawing 8: the high-resolution spectra figure that the optoacoustic detector that provides with the utility model obtains
Claims (6)
1, a kind of novel low-noise acousto-optic detector of sound that comprises radome, vacuum valve, binding post, electret, photoacoustic cell, detector window protective device and totally-enclosed external form that feature of the present utility model is made up of sodium chloride single crystal sheet (1), deep hole light hurdle (2), dry sound suppressor (3), gas channel (4).
2, optoacoustic detector according to claim 1 is characterized in that sodium chloride single crystal sheet (1) is bonded in window place, stainless steel cavity (7) two ends.
3, optoacoustic detector according to claim 1 is characterized in that the vacuum rubber circle (5) between photoacoustic cell (9) and the radome (7) has the right angle aperture.
4, optoacoustic detector according to claim 1 is characterized in that the shape on deep hole light hurdle (2) is cylindrical.
5, optoacoustic detector according to claim 1 is characterized in that dry sound suppressor (3) is the porous cavity.
6,, it is characterized in that aperture (4) is communicated with cavity (20) before cylindrical deep hole (19) and the window according to claim 1,4 described optoacoustic detectors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN198585201064U CN85201064U (en) | 1985-04-01 | 1985-04-01 | Low noise photoacoustic detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN198585201064U CN85201064U (en) | 1985-04-01 | 1985-04-01 | Low noise photoacoustic detector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN85201064U true CN85201064U (en) | 1986-02-19 |
Family
ID=4797216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN198585201064U Ceased CN85201064U (en) | 1985-04-01 | 1985-04-01 | Low noise photoacoustic detector |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN85201064U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102169085A (en) * | 2010-12-10 | 2011-08-31 | 中国科学院安徽光学精密机械研究所 | Temperature-controlled photo-acoustic absorption spectrum measuring apparatus |
| CN107560730A (en) * | 2017-08-24 | 2018-01-09 | 中国科学院电子学研究所 | Bicavate photo-acoustic spectrometer |
-
1985
- 1985-04-01 CN CN198585201064U patent/CN85201064U/en not_active Ceased
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102169085A (en) * | 2010-12-10 | 2011-08-31 | 中国科学院安徽光学精密机械研究所 | Temperature-controlled photo-acoustic absorption spectrum measuring apparatus |
| CN102169085B (en) * | 2010-12-10 | 2013-07-03 | 中国科学院安徽光学精密机械研究所 | Temperature-controlled photo-acoustic absorption spectrum measuring apparatus |
| CN107560730A (en) * | 2017-08-24 | 2018-01-09 | 中国科学院电子学研究所 | Bicavate photo-acoustic spectrometer |
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| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CE01 | Termination of patent right | ||
| CE01 | Termination of patent right |