GB2262338A - Infra red gas detector - Google Patents
Infra red gas detector Download PDFInfo
- Publication number
- GB2262338A GB2262338A GB9212942A GB9212942A GB2262338A GB 2262338 A GB2262338 A GB 2262338A GB 9212942 A GB9212942 A GB 9212942A GB 9212942 A GB9212942 A GB 9212942A GB 2262338 A GB2262338 A GB 2262338A
- Authority
- GB
- United Kingdom
- Prior art keywords
- infra red
- porous
- tube
- detector
- chamber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000002184 metal Substances 0.000 claims abstract description 5
- 239000000463 material Substances 0.000 claims abstract description 4
- 229920003023 plastic Polymers 0.000 claims abstract description 4
- 239000004033 plastic Substances 0.000 claims abstract description 4
- 239000000919 ceramic Substances 0.000 claims abstract description 3
- 229920002994 synthetic fiber Polymers 0.000 claims abstract 2
- 239000007789 gas Substances 0.000 claims description 39
- 230000005540 biological transmission Effects 0.000 claims description 2
- 239000011148 porous material Substances 0.000 claims 1
- 239000012466 permeate Substances 0.000 abstract description 2
- 230000005855 radiation Effects 0.000 abstract description 2
- 238000010521 absorption reaction Methods 0.000 abstract 2
- 239000000523 sample Substances 0.000 description 10
- 238000010276 construction Methods 0.000 description 7
- 230000009977 dual effect Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 3
- 231100001261 hazardous Toxicity 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 230000003750 conditioning effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
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
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3504—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
-
- 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
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
- G01N21/03—Cuvette constructions
- G01N2021/0378—Shapes
- G01N2021/0382—Frustoconical, tapered cell
-
- 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
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
- G01N21/03—Cuvette constructions
- G01N21/05—Flow-through cuvettes
- G01N2021/052—Tubular type; cavity type; multireflective
-
- 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
- G01N21/84—Systems specially adapted for particular applications
- G01N21/85—Investigating moving fluids or granular solids
- G01N2021/8578—Gaseous flow
- G01N2021/8585—Gaseous flow using porous sheets, e.g. for separating aerosols
Abstract
An infra red gas detector has as its gas sample chamber, a porous hollow tube 4. The sample gas or air can freely diffuse or permeate through the walls of the tube and gain access to the inner chamber where infra red absorption can take place. The internal tube walls additionally act as a light guide ensuring that maximum infra red light reaches detectors. The tube 4 may be constructed from a number of different materials including sintered metal, ceramic, plastics or other synthetic materials, and may be parallel, tapered, arcuate, coiled or T-shaped. The infra red source 5 includes a modulator, and radiation reaches a detector 2 by way of a filter 3 set to a frequency corresponding to an absorption frequency of the gas to be detected. A second filter and detector are provided as references to compensate for physical variations. <IMAGE>
Description
INFRA RED GAS DETECTOR
This invention relates to infra red gas detectors and specifically to methods of construction of such detectors.
Infra red gas detectors. of the non dispersive infra red type.
are well known devices which comprise a modulated infra red source. dual wavelength filters, dual infra red solid state detectors and associated control and conditioning electronics.
The detector is essentially an absorbtiometer in which the radiation from the infra red source is passed through the sample, through two thin film wavelenth selective transmission filters, to isolate the gas adsorbtion band, and on to the two detectors. To handle the signal electrically, the infra red source is modulated either electrically or by means of a mechanical shutter. When the selective gas is present in the beam path. adsorbtion occurs thus reducing the received beam strength and providing an accurate measure of the gas concentration. The second filter and detector provide a reference source used to compensate for physical variables.
Sometimes a simpler arrangement is adopted using only a single filter and detector with compensation incorporated into the electronics.
A cheaper known alternative to the dual detector system is a single detector arrangement whereby additional electronics give some degree of compensation for environmental factures.
In known detectors of both these types. use as point detectors for use in hazardous area environments. the physical construction is as shown in fig 1. The flameproof certification requirement for use In hazardous areas forces the enclosure I the infra red source. detectors and associated electronics in an approved flameproof housing.The infra red beam is made to pass through a transparent aperture. traverse the sample gas area and reflect back through the aperture to the detectors. via an externally mounted mirror. This type of detector is referred to as an 'op n cell design wherein the sample chamber is formed between the aperture and the reflective mirror. The construction is necessarily expensive and the infra red beam diverges causing a signif@cant reduction in beam strength thus making the detection more difficu@t particularly against background noise.
An alternative arrangement of detector used takes the form of a flow through gas chamber where the gas sample is introduced into the chamber r using an air pumping system. The infra red source and detectors etc are located at the extremes the chamber with the beam traversing the internal cavity. Again the design is necessarily complicated by the flow system, piping, pump and flow metering. This makes for a complicateed detector. See fig 2.
The object of the present invention is to overcome the main constructional limitations of the above descrlbed embodiments and produce an infra red point detector having a simple diffusion controlled gas chamber which results in an improved, more robust and economic detector. The design may be used in a number of different arrangements for both single and dual detector systems. Additionally, the invention can be used in the design of a range of different instruments but not limited to, portable instruments, point detectors, exhaust stack detectors and simple hand held detector probes.
According to the present invention there is a porous sintered metal, ceramic, plastic or synthetic hollow tube that forms the basis of the sample chamber. The tube walls are of sufficiently fine porosity to allow the gases to diffuse or permeate through the tube wall into the gas chamber. The tube is also of sufficient diameter which when combined with the fine porosity of the walls, allows the tube to act as an optical guide for the internal infra red beam. To enhance the internal reflection of the tube wall, the inner walling may be coated with a reflective material by one of several techniques. The tube may be constructed with parailel walls or may be tapered to accomodate two detectors side b side.
Alternatively an embodiment of the design could use an arcing (circular) arrangement or spiral construction of the tubing. The porous tubing construction can also apply to fibre optic cable where the optical fibre may be constructed with porous walls to allow gases to diffuse through and may be deployed over several metres distance.
A further method of construction may use a standard tube of an materiai , perforated with several holes along its length. and sleeved with a second fine porous tube. The whole then acting as the porous gas chamber.
In a preferred embodiment of the invention the design of a flameproof infra red detector is described by wax of example and with reference to the accompanying drawings in which Figure 3 is a cross section showing the essential features of an infra red gas detector having a parallel porous tube as the gas sample chamber.
Figure 1 is a cross section showing the essential features of an infra red gas detector having a tapered porous tube as the gas sample chamber
Figure 5 Is a cross section showing the essential features of an infra red gas detector having a circular type porous tube as the gas sample chamber.
Figure 6 is a cross section showing the essential features of an infra red gas detector having a "T" shape porous tube as the gas sample chamber. with a dual detector arrangement. The infra red source is mounted midway and transmits down both sections of the porous chamber.
Referring to figure 3 an infra red gas detector has an enclosure 1 possibly of flameproof construction to which is attached a porous tube 4 having a fine porous structure capable of allowing gases to pass through but sufficiently fine to block dust and particulates. The infra red solid state detector 2 and the wavelength selective filter 3 are mounted internai to the enclosure adjacent to the end of the porous tube 4. The second detector and filter are also located adjacent to the tube end so that infra red light travelling along the tube fall onto both detectors and filters.
the other end of the porous tube 4 is a metal or plastic housing into which is fitted the infra red source
Moduiated infra. reci light from the source 5 passes through the porous tube 4, also referred to as the gas chamber, through the f@@ter 3 and falls on the detector 2. The filter 3 only allows infra red light of the specified wavelength corresponding to the gas to he detected to pass through to the detector 2.Gases n she atmosphere diffuse through the porous tube wall and enter the gas chamber passing through the infra red beam wherein any gas for which the fiiter @ has been selected to detect. absorbs infra red energy. There is a corresponding reduction in intensity of energy reaching the detector 2 which thus is a measure of the gas concentration within the gas cnam@er.
In@-rnal reflections within the gas cham@er can be enhanced by the production of a reflective surface on the internal walls of the porous tube 4. The essential feature of the invention is the manufacture of the porous tube 4. Experts in the field of producing porous sintered metal tubes of the type described ab@@e are @ccumatic Engineering Ltd but examples of this and @ther materials are available from several sources.
Claims (8)
1 An infra red gas detector wherein the infra red beam is operated within a length of parallel hollow tube, having walls constructed to be highly porous to gases, and forms the basis of the gas chamber. This essential feature allows the gas to diffuse freely through the tube walls over its entire length.
2 An infra red gas detector as claimed in 1 above wherein the length of porous chamber tube is tapered to allow additional detector and infra red source mounting arrangements.
3 An infra red gas detector as claimed in 1 above wherein the porous chamber tube may be shaped in the form of an arc or semi-circle.
4 An infra red gas detector as claimed in 1 above wherein the porous chamber tube may be shaped in the form of a coil or spiral.
5 An infra red gas detector as claimed in l above wherein the porous chamber tube may be shaped in the form of an T" with the source mounted at the mid section.
6 An infra red detector wherein the porous tube may be constructed from porous sintered metal, porous ceramic, porous plastic or other porous synthetic material capable of being manufactured.
7 An infra red detector wherein the porous tube chamber may be constructed from a standard perforated tube with a fine porous sleeve fitted over. Any of the materials described in claim 6 above may by used and the porous chamber formed into any shape described in the above claims.
8 An infra red detector wherein the porous tube chamber may be shaped in the form of a disc with a hollow centre section acting as the chamber. Indeed. any shape may be used that uses the principle of a porous chamber constructed from porous material that will allow internal transmission of an infra red beam.
n An infra red Das detector substantially described in figures 3 to > ) of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9212942A GB2262338A (en) | 1991-07-02 | 1992-06-18 | Infra red gas detector |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB919114274A GB9114274D0 (en) | 1991-07-02 | 1991-07-02 | Infra red gas detector |
| GB9212942A GB2262338A (en) | 1991-07-02 | 1992-06-18 | Infra red gas detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9212942D0 GB9212942D0 (en) | 1992-07-29 |
| GB2262338A true GB2262338A (en) | 1993-06-16 |
Family
ID=26299172
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9212942A Withdrawn GB2262338A (en) | 1991-07-02 | 1992-06-18 | Infra red gas detector |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2262338A (en) |
Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0696732A1 (en) * | 1994-08-12 | 1996-02-14 | Texas Instruments Incorporated | Nondispersive infrared gas analyzer |
| WO1996006345A1 (en) * | 1994-08-18 | 1996-02-29 | Msa (Britain) Limited | Infrared gas detector |
| DE4438244C1 (en) * | 1994-10-26 | 1996-03-07 | Frobenius Wolf Dietrich Prof D | Gas component concn. in mixture measuring appts. for esp. carbon dioxide in atmos. |
| US5872359A (en) * | 1995-07-27 | 1999-02-16 | American Sterilizer Company | Real-time monitor and control system and method for hydrogen peroxide vapor decontamination |
| WO1999022221A1 (en) * | 1997-10-28 | 1999-05-06 | Engelhard Sensor Technologies, Inc. | Diffusion-type ndir gas analyzer with convection flow |
| DE19743954A1 (en) * | 1997-10-04 | 1999-06-02 | Wwu Wissenschaftliche Werkstat | Arrangement for analyzing motor vehicle exhaust gas |
| US5923035A (en) * | 1997-04-04 | 1999-07-13 | Dragerwerk Ag | Infrared absorption measuring device |
| WO1999066311A1 (en) * | 1998-06-18 | 1999-12-23 | Teledyne Industries, Inc. | Infrared multiple gas analyzer and analysis |
| US6410918B1 (en) * | 1997-10-28 | 2002-06-25 | Edwards Systems Technology, Inc. | Diffusion-type NDIR gas analyzer with improved response time due to convection flow |
| WO2004010116A1 (en) | 2002-07-22 | 2004-01-29 | Senseair Ab | Gas analysis arrangement |
| WO2004023113A1 (en) * | 2002-09-03 | 2004-03-18 | E2V Technologies (Uk) Limited | Gas sensors |
| WO2005062024A1 (en) * | 2003-12-20 | 2005-07-07 | Robert Bosch Gmbh | Gas sensor |
| DE102005003050B3 (en) * | 2005-01-22 | 2006-06-29 | Dräger Safety AG & Co. KGaA | Gas sensor, for use e.g. in chemical or petroleum plants, including porous, gas-permeable, water-impermeable cap for protection against harsh environments, fittable with calibration gas supplying adapter |
| DE102005003049B3 (en) * | 2005-01-22 | 2006-06-29 | Dräger Safety AG & Co. KGaA | Combustible gas e.g. methane gas, sensor e.g. infrared optical sensor for chemical industry, has measuring unit which is differentiated from atmosphere by sintered metal body which is re sintered in vacuum during specific temperature |
| EP2133684A1 (en) * | 2008-06-11 | 2009-12-16 | Oldham | Measurement cell for a device for detecting the presence of a gas in an atmosphere. |
| US7664607B2 (en) | 2005-10-04 | 2010-02-16 | Teledyne Technologies Incorporated | Pre-calibrated gas sensor |
| EP2492666A1 (en) * | 2011-02-25 | 2012-08-29 | Wacker Chemie AG | Device and method for determining a gas concentration in a flowing gas mixture |
| US20160170078A1 (en) * | 2014-12-12 | 2016-06-16 | Lingacom Ltd. | Large Scale Gas Electron Multiplier and Detection Method |
| WO2021069800A1 (en) * | 2019-10-10 | 2021-04-15 | Teknologian Tutkimuskeskus Vtt Oy | Method and apparatus for analyzing gaseous samples |
| EP4336171A1 (en) * | 2022-09-06 | 2024-03-13 | Electronics and Telecommunications Research Institute | Non-dispersive infrared gas sensor using gas-permeable polymer optical waveguide and manufacturing method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1538833A (en) * | 1977-11-28 | 1979-01-24 | Adrian W | Device for measuring the concentration of gas |
| GB2110818A (en) * | 1981-11-14 | 1983-06-22 | Ferranti Ltd | Non-dispersive gas analyser |
| US4622464A (en) * | 1983-11-15 | 1986-11-11 | Fuji Electric Co., Ltd. | Infrared gas analyzer |
| US4709150A (en) * | 1986-03-18 | 1987-11-24 | Burough Irvin G | Method and apparatus for detecting gas |
| GB2226401A (en) * | 1988-12-13 | 1990-06-27 | Robin John Hutchinson | Gas analysis apparatus |
| WO1991005240A1 (en) * | 1989-09-29 | 1991-04-18 | Atomic Energy Of Canada Limited | Infrared-based gas detector |
-
1992
- 1992-06-18 GB GB9212942A patent/GB2262338A/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1538833A (en) * | 1977-11-28 | 1979-01-24 | Adrian W | Device for measuring the concentration of gas |
| GB2110818A (en) * | 1981-11-14 | 1983-06-22 | Ferranti Ltd | Non-dispersive gas analyser |
| US4622464A (en) * | 1983-11-15 | 1986-11-11 | Fuji Electric Co., Ltd. | Infrared gas analyzer |
| US4709150A (en) * | 1986-03-18 | 1987-11-24 | Burough Irvin G | Method and apparatus for detecting gas |
| GB2226401A (en) * | 1988-12-13 | 1990-06-27 | Robin John Hutchinson | Gas analysis apparatus |
| WO1991005240A1 (en) * | 1989-09-29 | 1991-04-18 | Atomic Energy Of Canada Limited | Infrared-based gas detector |
Cited By (34)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0696732A1 (en) * | 1994-08-12 | 1996-02-14 | Texas Instruments Incorporated | Nondispersive infrared gas analyzer |
| WO1996006345A1 (en) * | 1994-08-18 | 1996-02-29 | Msa (Britain) Limited | Infrared gas detector |
| DE4438244C1 (en) * | 1994-10-26 | 1996-03-07 | Frobenius Wolf Dietrich Prof D | Gas component concn. in mixture measuring appts. for esp. carbon dioxide in atmos. |
| US5872359A (en) * | 1995-07-27 | 1999-02-16 | American Sterilizer Company | Real-time monitor and control system and method for hydrogen peroxide vapor decontamination |
| US5923035A (en) * | 1997-04-04 | 1999-07-13 | Dragerwerk Ag | Infrared absorption measuring device |
| DE19743954C2 (en) * | 1997-10-04 | 2000-10-12 | Wwu Wissenschaftliche Werkstat | Cold start measuring system for measuring the cold start emission |
| DE19743954A1 (en) * | 1997-10-04 | 1999-06-02 | Wwu Wissenschaftliche Werkstat | Arrangement for analyzing motor vehicle exhaust gas |
| WO1999022221A1 (en) * | 1997-10-28 | 1999-05-06 | Engelhard Sensor Technologies, Inc. | Diffusion-type ndir gas analyzer with convection flow |
| US6410918B1 (en) * | 1997-10-28 | 2002-06-25 | Edwards Systems Technology, Inc. | Diffusion-type NDIR gas analyzer with improved response time due to convection flow |
| AU753912B2 (en) * | 1997-10-28 | 2002-10-31 | GE Interlogix Pty Ltd | Diffusion-type NDIR gas analyzer with convection flow |
| WO1999066311A1 (en) * | 1998-06-18 | 1999-12-23 | Teledyne Industries, Inc. | Infrared multiple gas analyzer and analysis |
| US6201245B1 (en) | 1998-06-18 | 2001-03-13 | Robert J. Schrader | Infrared, multiple gas analyzer and methods for gas analysis |
| WO2004010116A1 (en) | 2002-07-22 | 2004-01-29 | Senseair Ab | Gas analysis arrangement |
| US8368895B2 (en) | 2002-07-22 | 2013-02-05 | Senseair Ab | Gas analysis arrangement |
| WO2004023113A1 (en) * | 2002-09-03 | 2004-03-18 | E2V Technologies (Uk) Limited | Gas sensors |
| WO2005062024A1 (en) * | 2003-12-20 | 2005-07-07 | Robert Bosch Gmbh | Gas sensor |
| US7880886B2 (en) | 2003-12-20 | 2011-02-01 | Robert Bosch Gmbh | Gas sensor |
| DE102005003049B3 (en) * | 2005-01-22 | 2006-06-29 | Dräger Safety AG & Co. KGaA | Combustible gas e.g. methane gas, sensor e.g. infrared optical sensor for chemical industry, has measuring unit which is differentiated from atmosphere by sintered metal body which is re sintered in vacuum during specific temperature |
| GB2422431A (en) * | 2005-01-22 | 2006-07-26 | Draeger Safety Ag & Co Kgaa | Explosion-protected gas sensor |
| US7310991B2 (en) | 2005-01-22 | 2007-12-25 | Dräger Safety AG & Co. KGaA | Explosion-proof gas sensor |
| US7406854B2 (en) | 2005-01-22 | 2008-08-05 | Dräger Safety AG & Co. KGaA | Gas sensor |
| DE102005003050B3 (en) * | 2005-01-22 | 2006-06-29 | Dräger Safety AG & Co. KGaA | Gas sensor, for use e.g. in chemical or petroleum plants, including porous, gas-permeable, water-impermeable cap for protection against harsh environments, fittable with calibration gas supplying adapter |
| GB2422431B (en) * | 2005-01-22 | 2007-03-21 | Draeger Safety Ag & Co Kgaa | Explosion-protected gas sensor |
| US7664607B2 (en) | 2005-10-04 | 2010-02-16 | Teledyne Technologies Incorporated | Pre-calibrated gas sensor |
| EP2133684A1 (en) * | 2008-06-11 | 2009-12-16 | Oldham | Measurement cell for a device for detecting the presence of a gas in an atmosphere. |
| EP2492666A1 (en) * | 2011-02-25 | 2012-08-29 | Wacker Chemie AG | Device and method for determining a gas concentration in a flowing gas mixture |
| JP2012177694A (en) * | 2011-02-25 | 2012-09-13 | Wacker Chemie Ag | Device and method for determining gas concentration in flowing gas mixture |
| US8576397B2 (en) | 2011-02-25 | 2013-11-05 | Wacker Chemie Ag | Device and method for determining a gas concentration in a flowing gas mixture |
| KR101423156B1 (en) | 2011-02-25 | 2014-07-25 | 와커 헤미 아게 | Device and method for determining a gas concentration ina flowing gas mixture |
| US20160170078A1 (en) * | 2014-12-12 | 2016-06-16 | Lingacom Ltd. | Large Scale Gas Electron Multiplier and Detection Method |
| US10191180B2 (en) * | 2014-12-12 | 2019-01-29 | Lingacom Ltd. | Large scale gas electron multiplier and detection method |
| WO2021069800A1 (en) * | 2019-10-10 | 2021-04-15 | Teknologian Tutkimuskeskus Vtt Oy | Method and apparatus for analyzing gaseous samples |
| US11774350B2 (en) | 2019-10-10 | 2023-10-03 | Teknologian Tutkimuskeskus Vtt Oy | Method and apparatus for analyzing gaseous samples |
| EP4336171A1 (en) * | 2022-09-06 | 2024-03-13 | Electronics and Telecommunications Research Institute | Non-dispersive infrared gas sensor using gas-permeable polymer optical waveguide and manufacturing method |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9212942D0 (en) | 1992-07-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| GB2262338A (en) | Infra red gas detector | |
| JP3606866B2 (en) | Multi-channel gas sample chamber | |
| CN110621980B (en) | Gas measurement system | |
| US5502308A (en) | Diffusion-type gas sample chamber | |
| CA1078641A (en) | Pulsed light colorimeter | |
| US6469303B1 (en) | Non-dispersive infrared gas sensor | |
| FI105595B (en) | Improved gas sampling chamber | |
| FI95322C (en) | Spectroscopic measuring sensor for analyzing media | |
| JPH04232838A (en) | Absorbing cell of fluid sample | |
| US20020155592A1 (en) | Fluorescence detection system including a photonic band gap structure | |
| CA1272043A (en) | Method of and apparatus for measuring floating fine particles | |
| EP3295151B1 (en) | Hollow fibre waveguide gas cells | |
| CA2028148C (en) | Optical probe for fluid light transmission properties | |
| CA1257980A (en) | Process and device for determining the cloud point of a diesel oil | |
| GB2329707A (en) | Infra-red absorption measurement | |
| CN109342348A (en) | A kind of binary channels infrared gas sensor | |
| US20040233426A1 (en) | Raman probe and Raman spectrum measuring apparatus utilizing the same | |
| WO1996001418A1 (en) | Ndir gas analysis using spectral ratioing technique | |
| JP3895434B2 (en) | Tubular attenuated lightwave sensor for molecular absorption spectroscopy | |
| US3506359A (en) | Apparatus for measuring light absorption of a sample | |
| CN209182234U (en) | A kind of binary channels infrared gas sensor | |
| JPH08184557A (en) | Optical gas detector | |
| JPH08110303A (en) | Method and device for measuring concentration of particulate | |
| FI72607B (en) | FOTOELEKTRISK OMVANDLARE AV PARTIKELSTORLEKEN HOS ETT FINFOERDELAT MEDIUM. | |
| CN116685842A (en) | Optical fluid sensing device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |