DE2655062A1 - Photometric nitrogen oxide determination - in exhaust gases contg. sulphur di:oxide using a tilted interference filter - Google Patents

Photometric nitrogen oxide determination - in exhaust gases contg. sulphur di:oxide using a tilted interference filter

Info

Publication number
DE2655062A1
DE2655062A1 DE19762655062 DE2655062A DE2655062A1 DE 2655062 A1 DE2655062 A1 DE 2655062A1 DE 19762655062 DE19762655062 DE 19762655062 DE 2655062 A DE2655062 A DE 2655062A DE 2655062 A1 DE2655062 A1 DE 2655062A1
Authority
DE
Germany
Prior art keywords
interference filter
oxide
determination
exhaust gases
nitrogen oxide
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.)
Granted
Application number
DE19762655062
Other languages
German (de)
Other versions
DE2655062C2 (en
Inventor
Walter Fabinski
Helmut Dr Meinel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Deutsches Zentrum fuer Luft und Raumfahrt eV
Original Assignee
Deutsche Forschungs und Versuchsanstalt fuer Luft und Raumfahrt eV DFVLR
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Deutsche Forschungs und Versuchsanstalt fuer Luft und Raumfahrt eV DFVLR filed Critical Deutsche Forschungs und Versuchsanstalt fuer Luft und Raumfahrt eV DFVLR
Priority to DE19762655062 priority Critical patent/DE2655062A1/en
Publication of DE2655062A1 publication Critical patent/DE2655062A1/en
Application granted granted Critical
Publication of DE2655062C2 publication Critical patent/DE2655062C2/de
Granted legal-status Critical Current

Links

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

Landscapes

  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (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 Analysing Materials By Optical Means (AREA)

Abstract

In the parent patent, an interference filter is used in the photometer. In the addn. to avoid the effect of SO2 which is also present in the waste gas and adversely affects the accuracy of measurement, the interference filter is 60-12 angstroms when used for the detn. of nitrogen oxides in waste gases contg. a high percentage of SO2, and is 20-60 angstroms for waste gases contg. a lower amt. of SO2, e.g. in car engine exhaust gases. Pref. the filter exhibits an inclined distribution of permeability with wavelength.

Description

Vorrichtung zur Bestimmung von Stickoxid Device for the determination of nitric oxide

Die Erfindung betrifft eine Vorrichtung zur Bestimmung von Stickoxid nach Patent 24 07 133, wobei im Strahlenweg an Stelle eines Monochromators ein Interferenzfilter vorgesehen ist.The invention relates to a device for determining nitrogen oxide according to patent 24 07 133, with an interference filter in the beam path instead of a monochromator is provided.

Enthält das zu analysierende Probengasgemisch außer Stickoxid weitere Gase, die ein der Meßkomponente überlagertes, wellenlängenabhängiges Absorptionsvermögen aufweisen, so wird der Meßwert für die Meßkomponente verfälscht. Die photometrische Vorrichtung weist eine "QuerempSindlichkeit" gegenüber dem störenden Begleitgas auf. So muß bei der Messung von NO in Abgas und Luft mit einem erheblichen Anteil an SO2 gerechnet werden. Da SO2 in dem benutzten, durch das Interferenzfilter festgelegten Wellenlängenbereich, , ein von der Wellenlänge abhängiges Absorptionsvermögen aufweist, wird das lçießergebnis fehlerhaft.If the sample gas mixture to be analyzed contains more than nitrogen oxide Gases that have a wavelength-dependent absorption capacity superimposed on the measuring component have, the measured value for the measuring component is falsified. The photometric The device has a "cross-sensitivity" to the interfering accompanying gas on. For example, when measuring NO in exhaust gas and air, a considerable proportion must be used can be counted on SO2. Because SO2 is used in the, through the interference filter set Wavelength range,, has an absorption capacity dependent on the wavelength, the loosening result will be faulty.

Die Erfindung stellt sich die Aufgabe, die photometrische Vorrichtung so einzurichten, daß sich die Querempfindlichkeit weitgehend unterdrücken läßt. Erfindungsgemäß gelingt dies dadurch, daß das Interferenzfilter kippbar und in der gekippten Lage feststellbar ist.The invention has the object, the photometric device to be set up in such a way that the cross-sensitivity can be largely suppressed. According to the invention, this is achieved in that the interference filter is tiltable and in the tilted position can be determined.

Durch das Kippen des Interferenzfilters wird dessen Absorption wellenlängenabhängig verändert. Es kann eine Kippstellung gefunden werden, bei der die ursprünglich vorhandene Querempfindlichkeit des Photometers gegenüber störenden Begleitgasen auf ein Minimum herabgesetzt ist. Bei der Messung des NO in Rauchgasen mit hohem S02-Anteil ist ein Interferenzfilter mit einer Bandbreite vom 60-120 A, vorteilhaft, bei der Messung des NO im Motorenabgasen mit geringerem Anteil an SO2 eines mit einer Bandbreite von 20-60 A. Besonders vorteilhaft sind Bilter mit einer Schiefverteilung der Durchlässigkeit mit der ellenlänge.By tilting the interference filter, its absorption becomes dependent on the wavelength changes. A tilt position can be found in which the originally existing Cross-sensitivity of the photometer to interfering accompanying gases to a minimum is reduced. When measuring NO in flue gases with a high proportion of S02, an interference filter with a bandwidth of 60-120 A, advantageous for the measurement of the NO in the engine exhaust with a lower proportion of SO2 one with a bandwidth from 20-60 A. Bilter with a skewed distribution of permeability are particularly advantageous with the ellen length.

Die Wirksamkeit der erfindungsgemäßen Maßnahme wird anhand der Zeichnung demonstriert, die ein Diagramm einer NO-Konzentrationsmessung von Verbrennungaluft bei Anwesenheit von S02 vergleichsweise mit dem bekannten und dem erfindungsgemäßen Gerät wiedergibt. Auf der Ordinate ist die Querempfindlichkeit in Prozent Meßfehler der NO-Konzentration aufgetragen und auf der abszisse die SO2-Konzentration, wobei die Kurve F1 die Querempfindlichkeit des bekannten Gerätes zeigt und die Kurve F2 die Querempfindlichkeit des erfindungsgemäßen Gerätes. Es ist ersichtlich, daß bis 50 Xo ansteigende Meßfehler bei SO-Konzentrationswerte bis 1200 ppm durch die Erfindung auf Fenlerwerte unter 1-2 % reduziert werden. Besonders hervorzuheben ist noch, daß die Nullpunktstabilität durch die erfindungsgemäße Maßnahme nicht wesentlicher beeinträchtigt wird.The effectiveness of the measure according to the invention is based on the drawing demonstrates a diagram of a NO concentration measurement of combustion air in the presence of SO2, it is compared with the known and the inventive Device is playing. The cross-sensitivity is on the ordinate as a percentage of the measurement error plotted the NO concentration and on the abscissa the SO2 concentration, where the curve F1 shows the cross sensitivity of the known device and the curve F2 the cross-sensitivity of the device according to the invention. It can be seen that Up to 50 Xo increasing measurement errors at SO concentration values up to 1200 ppm due to the Invention can be reduced to fenler values below 1-2%. Of particular note is still that the zero point stability by the measure according to the invention is not is significantly impaired.

Claims (4)

Patentansprüche: 1. Vorrichtung zur Bestimmung von Stickoxid nach Patent - 07 1)3, wobei im Strahlenweg anstelle eines Monochromators ein Interferenzfilter vorgesehen ist, dadurch gekennzeichnet, daß das Interferenzfilter kippbar und in der gekippten Lage feststellbar ist. Claims: 1. Device for the determination of nitrogen oxide according to Patent - 07 1) 3, with an interference filter in the beam path instead of a monochromator is provided, characterized in that the interference filter is tiltable and in the tilted position can be determined. 2. Vorrichtung nach Anspruch 1 zur Bestimmung von Stickoxid in Rauchgasen mit hohem S02-hnteil, dadurch gekennzeichnet, daß das Interferenzfilter eine Bandbreite von 60-120 A aufweist. 2. Device according to claim 1 for the determination of nitrogen oxide in flue gases with a high SO2 content, characterized in that the interference filter has a bandwidth of 60-120 A. 3. Vorrichtung nach Anspruch 1 zur Bestimmung von Stickoxid in Notorenabgasen mit geringem S02-Anteil, dadurch gekennzeichnet, daß das Interferenzfilter eine Bandbreite von 20-60 A aufweist. 3. Device according to claim 1 for the determination of nitrogen oxide in notor's exhaust gases with a low proportion of S02, characterized in that the interference filter is a Has a bandwidth of 20-60 A. 4. Vorrichtung nach anspruch 1 bis 3, dadurch. gekennzeichnet, daß das Interferenzfilter eine Schiefverteilung seiner Durchlässigkeit mit der Wellenlänge aufweist. 4. Device according to claim 1 to 3, thereby. marked that the interference filter has a skewed distribution of its transmittance with the wavelength having.
DE19762655062 1976-12-04 1976-12-04 Photometric nitrogen oxide determination - in exhaust gases contg. sulphur di:oxide using a tilted interference filter Granted DE2655062A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE19762655062 DE2655062A1 (en) 1976-12-04 1976-12-04 Photometric nitrogen oxide determination - in exhaust gases contg. sulphur di:oxide using a tilted interference filter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19762655062 DE2655062A1 (en) 1976-12-04 1976-12-04 Photometric nitrogen oxide determination - in exhaust gases contg. sulphur di:oxide using a tilted interference filter

Publications (2)

Publication Number Publication Date
DE2655062A1 true DE2655062A1 (en) 1978-06-08
DE2655062C2 DE2655062C2 (en) 1989-05-18

Family

ID=5994701

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19762655062 Granted DE2655062A1 (en) 1976-12-04 1976-12-04 Photometric nitrogen oxide determination - in exhaust gases contg. sulphur di:oxide using a tilted interference filter

Country Status (1)

Country Link
DE (1) DE2655062A1 (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2407133A1 (en) * 1974-02-15 1975-08-21 Deutsche Forsch Luft Raumfahrt METHOD AND DEVICE FOR DETERMINING NITROGEN OXIDE

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2407133A1 (en) * 1974-02-15 1975-08-21 Deutsche Forsch Luft Raumfahrt METHOD AND DEVICE FOR DETERMINING NITROGEN OXIDE

Also Published As

Publication number Publication date
DE2655062C2 (en) 1989-05-18

Similar Documents

Publication Publication Date Title
US4771176A (en) Method for quantitative analysis of hydrocarbon
EP0426982A2 (en) Adjustment procedure for a non-dispersive infra-red gas analyser
DE2225802B2 (en) Method and device for determining the concentration of a component in a gaseous sample mixture
DE3650094T2 (en) Absorption analysis method.
DE3236792C2 (en) Gas test tubes with reagent strips
US4332770A (en) Apparatus for analyzing the carbon content of metals
Rowland Jr Photoelectric Colorimetry
WO2019191798A1 (en) Method for calibrating a mass flow meter in a constant volume sampling (see the s) exhaust gas analysis system
EP0530655A2 (en) Method and apparatus for controlling an internal combustion engine and testing its catalytic converter
DE3030002A1 (en) NON-DISPERSIVE INFRARED GAS ANALYZER
DE2655062A1 (en) Photometric nitrogen oxide determination - in exhaust gases contg. sulphur di:oxide using a tilted interference filter
DE3116344C2 (en)
Leaderer et al. Relationship between sulfate aerosol and visibility
Butler The spectrographic determination of the rare earths
EP0613553A1 (en) Method for determining small quantities of carbon monoxide and nitrogen oxides in gaseous mixtures.
DE19819192C1 (en) Gas mixture analyzer determining oxygen and a further component, simultaneously, accurately, independently and compactly
DE2827345A1 (en) NON-DISPERSIVE INFRARED GAS ANALYZER
Margoshes et al. Fitting of analytical functions with digital computers in spectrochemical analysis
DE2910188C2 (en) Non-dispersive infrared gas analyzer
JPH04191654A (en) Continuously measuring method for concentration of nitrogen monoxide in gas
DE3419909A1 (en) Process for sulphur dioxide determination in flue gases
Butler et al. A system for on-line measurement of multicomponent emissions and engine operating parameters
DE19821136C2 (en) Device for analyzing the exhaust gas from motor vehicles
US4495418A (en) Method of standardizing IR breath alcohol device
EP0340519A2 (en) Pneumatic detector for NDIR analytical devices

Legal Events

Date Code Title Description
8110 Request for examination paragraph 44
AF Is addition to no.

Ref country code: DE

Ref document number: 2407133

Format of ref document f/p: P

D2 Grant after examination
8364 No opposition during term of opposition
8327 Change in the person/name/address of the patent owner

Owner name: DEUTSCHE FORSCHUNGSANSTALT FUER LUFT- UND RAUMFAHR