File:Photoacoustic-Spetroscope.svg

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Photoacoustic-Spetroscope.svg‎ (SVG file, nominally 1,365 × 800 pixels, file size: 50 KB)

Description

English: Exemplary assembly of a photoacoustic spectroscope for gas analysis with an acoustic cell.

Resonance ocours at a wavelength of double the resonator length. Instead of a chopper wheel, variation of the absorption could also be achieved with a tunable laser, modulating its frequency across absorption wavelength. Additional λ/4 tube elements could be added for example in the gas inlet to prevent unwanted flow noises. Electronic control elements, especially a lock-in amplifier, are not shown.

Light source (e. g. Laser)
Chopper wheel
semipermeable mirrors form an optical resonance system
cell windows (tilted for polarisation)
gas flow inlet and outlets
buffer gas volumes
acoustic sensor (e. g. microphone or transducer)
resonator

Deutsch: Beispielhafter Aufbau eines photoakustischen Spektroskops zur Gasanalyse mit einer Akustikzelle.

Resonanz tritt bei einer Wellenlänge auf, die das Doppelte der Länge des Resonators beträgt. Statt der Verwendung eines Chopperrades kann eine Variation der Absorption auch mit einem stimmbaren Laser erreicht werden, indem dessen Frequenz rund um die Absorptionswellenlänge moduliert wird. Ergänzende λ/4-Rohre können zum Beispiel in der Zuleitung eingebaut werden, um unerwünschte Strömungsgeräusche zu verhindern. Elektronische Steuerbauteile, insbesondere ein Lock-In-Verstärker, sind nicht abgebildet.

Lichtquelle (z. B. Laser)
Chopperrad
halbdurchlässige Spiegel bilden ein optisches Resonanzsystem
Ein- und Austrittsfenster (zur Polarisierung geneigt)
Zuleitung und Ableitungen des Gasflusses
Gasvolumen zur Pufferung
Akustiksensor (z. B. Mikrofon oder Transducer)
Resonator

Date

2008-8-15

Source

own work, with the utilisation of Image:Laser-symbol.svg by Spooky. For References, see below.

Author

Hk kng

Permission
(Reusing this image)

I, the copyright holder of this work, hereby publish it under the following license:

This file is licensed under the Creative Commons Attribution ShareAlike 3.0 License. In short: you are free to share and make derivative works of the file under the conditions that you appropriately attribute it, and that you distribute it only under a license identical to this one. Official license

[edit] References

Frans J.M. Harren, Gina Cotti, Jos Oomens, and Sacco te Lintel Hekkert: Photoacoustic Spectroscopy in Trace Gas Monitoring, in: R.A. Meyers (Ed.): Encyclopedia of Analytical Chemistry, Chichester 2000, ISBN 0471976709, S. 2203–2226
US patent 7263871 (2007-9-4) Selker et al. System and method for gas analysis using doubly resonant photoacoustic spectroscopy

English: This image was created as part of the Philip Greenspun illustration project.

File history

Click on a date/time to view the file as it appeared at that time.

	Date/Time	Thumbnail	Dimensions	User	Comment
current	12:33, 29 August 2008		1,365×800 (50 KB)	Hk kng (talk \| contribs)	(readability)
	22:32, 17 August 2008		1,365×800 (52 KB)	Hk kng (talk \| contribs)
	15:42, 15 August 2008		1,365×800 (53 KB)	Hk kng (talk \| contribs)	((minor rendering problems corrected)
	15:05, 15 August 2008		1,365×800 (51 KB)	Hk kng (talk \| contribs)	({{Information \|Description={{en\|Exemplary assembly of a photoacoustic spectroscope for gas analysis with an acoustic cell. Resonance ocours at a wavelength of double the resonator length. Instead of a chopper wheel, variation of the absorption could also)