GB2466181A - Monitoring of components of a gas mixture in a reduced pressure environment - Google Patents

Monitoring of components of a gas mixture in a reduced pressure environment Download PDF

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Publication number
GB2466181A
GB2466181A GB0822350A GB0822350A GB2466181A GB 2466181 A GB2466181 A GB 2466181A GB 0822350 A GB0822350 A GB 0822350A GB 0822350 A GB0822350 A GB 0822350A GB 2466181 A GB2466181 A GB 2466181A
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cell
gas
components
infrared radiation
gas mixture
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GB0822350D0 (en
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John David Black
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Rolls Royce PLC
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Rolls Royce PLC
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    • 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
    • G01N21/11—Filling or emptying of cuvettes
    • 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
    • G01N21/39—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/22—Fuels; Explosives
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/22—Fuels; Explosives
    • G01N33/225—Gaseous fuels, e.g. natural gas
    • 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
    • G01N21/0332—Cuvette constructions with temperature control
    • G01N2021/0335—Refrigeration of cells; Cold stages

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  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Pathology (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
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  • Engineering & Computer Science (AREA)
  • Food Science & Technology (AREA)
  • Medicinal Chemistry (AREA)
  • Optics & Photonics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

A device 1 for monitoring components of a gas mixture has a gas cell 4 for receiving a sample of the gas mixture. The device 1 also has an infrared radiation source 8 which delivers infrared radiation into the cell 4 for transmission through the sample, the transmitted infrared radiation being absorbed by components of the gas mixture at absorption wavelengths which are characteristic of those components. The device also has an infrared detector 9 which measures the transmitted infrared radiation, thereby enabling the monitoring of components of the gas mixture in the sample. The device 1 is connectable to a gas source 2 from which the cell 4 receives the sample. The device 1 further has a system 5, 7 for reducing the pressure of the sample in the cell 4 relative to the pressure of the source 2. Rapid reduction of pressure can cause significant expansion cooling of the sample.

Description

MONITORING OF COMPONENTS OF A GAS MIXTURE
The present invention relates to a device for monitoring components of a gas mixture, and particularly monitoring by measuring infrared absorption.
Natural gas is commonly used as fuel, and is mainly composed of methane with higher hydrocarbon, nitrogen and carbon dioxide often present in quantities of a few percent. However, even relatively clean natural gas may contain minor contaminants such as heavy hydrocarbon condensate, salts, sand, or methane hydrate and minor gaseous species such as hydrogen sulphide. Further, there is an increasing demand to use other gases, e.g. "syngas" (mainly hydrogen and carbon monoxide) or landfill gas, as fuel.
It is, therefore, desirable to he able monitor the components of fuel gas. In particular, the calorific value of a fuel gas is dependent on its chemical composition. In low emission gas turbines, for example, an increase in calorific value will lead to higher combustor temperatures and hence higher NOx emission, while a decrease in calorific value can lead to increased emission of CC, or worse, combustion instability leading to mechanical failure of an engine. Accurate on-line monitoring of composition can help to avoid these problems.
Infrared spectroscopy, including near infrared spectroscopy, is a promising techniques for monitoring gaseous fuel.
US 7248357 proposes a system for measuring heat energy in a combustible gas, in which infrared spectroscopy is used to determine the absorbance spectrum of the gas.
Comparison of the absorbance spectrum with reference spectra allows the heating value of the gas to be determined.
However, a difficulty with using infrared spectroscopy for on-line monitoring components of a gas, is that the gas may be at such a high pressure that molecular linewidths broaden and overlap, making it difficult to distinguish components of a mixture, especially a mixture of hydrocarbons, from an infrared absorption spectrum. For example, the gas pressure in a delivery pipe for a large industrial gas turbine is typically about 45 bar (4.5 MPa) Thus, in a first aspect, the present invention provides a device for monitoring components of a gas mixture, the device having: a gas cell for receiving a sample of the gas mixture, an infrared radiation source which delivers infrared radiation into the cell for transmission through the sample, the transmitted infrared radiation being absorbed by components of the gas mixture at absorption wavelengths which are characteristic of those components, and an infrared detector which measures the transmitted infrared radiation, thereby enabling the monitoring of components of the gas mixture in the sample; wherein the device is connectable to a gas source from which the cell receives the sample, and the device further has a system for reducing the pressure of the sample in the cell.
By reducing the pressure of the sample, molecular linewidths are narrowed and are often better separated from each other, allowing the relative absorptions by different components in the mixture to be determined more accurately.
The relative absorptions can in turn provide an indication of the relative amounts of the components in the mixture.
Preferably, the system for reducing the pressure includes means for evacuating the cell. For example, the cell may be evacuated before the sample is received therein, so that the sample expands on entry into the cell.
Advantageously, this can cause expansion cooling of the sample, which may simplify absorption spectra by reducing the number of populated molecular energy levels.
Typically, the pressure in the cell is lower than the pressure of the source, and the system for reducing the pressure includes a valve which controls the flow of gas from the source to the cell, the valve being adapted to be opened and closed at sufficiently high speed such that the sample of gas received by the cell from the source on opening and closing of the valve experiences a reduction in pressure. Preferably, the device further has a pressure sensor for the cell. The larger the reduction in pressure, the greater the amount of expansion cooling that can be achieved.
The device may further include means for cooling the gas cell relative to the temperature of the source.
Particularly when the sample undergoes expansion cooling, the means for cooling can maintain the sample at a low temperature. Preferably, the device further has a temperature sensor for the cell.
Typically, the pressure of the source is 10 bar or more. More typically, the pressure of the source is 20 bar or more, or 40 bar or more.
Typically, the pressure of the sample in the cell is reduced to atmospheric pressure or lower.
The infrared radiation source may deliver multi-wavelength infrared radiation into the cell, and the device may further have a spectrometer between the gas cell and the infrared detector.
For example, the spectrometer may disperse the multi-wavelength infrared radiation into an absorption spectrum, whereby individual wavelength bins of the spectrum can be separately measured by the detector.
Alternatively, the spectrometer may comprise a scanning interferometer, whereby a temporal intensity profile can be measured by the detector and the adsorption spectrum generated by taking the Fourier transform of the temporal intensity profile.
Alternatively, the infrared radiation source may deliver at any one time single wavelength infrared radiation into the cell. In this case, the infrared radiation source can deliver successive pulses of single wavelength infrared radiation into the cell, each pulse having a different wavelength. Each pulse can be tuned, for example, to a different absorption line of a different component of the gas mixture.
The system may further have a processor which determines from the measured infrared radiation an infrared absorption spectrum, and a display which displays the infrared absorption spectrum.
The system may further have a processor (which can be the same processor as a processor which determines an infrared absorption spectrum) which determines from the measured infrared radiation the presence of components in the gas mixture and/or the relative amounts of components in the gas mixture.
When the device has a pressure sensor and/or a temperature sensor, the or each processor may use the measured pressure and/or temperature in the cell to more accurately determine the infrared absorption spectrum, and/or the relative amounts of components in the gas mixture.
The device may be connected to the gas source.
Preferably the gas source is a gas pipeline, for example a fuel pipeline to an engine such as a gas turbine engine.
Indeed, another aspect of the invention provides, an engine, such as a gas turbine engine, having the device of the previous aspect connected a fuel gas pipeline of the engine. Preferably, the device has a processor which determines the presence of components in the gas mixture and/or the relative amounts of components in the gas mixture engine, and the engine has a control system which is in communication with the processor, the control system controlling the combustion of the fuel by the engine depending on which components are present in the gas mixture and/or on the relative amounts of components in the gas mixture as determined by the processor.
Another aspect of the invention provides the use of the device of the first aspect for monitoring components of a gas mixture in a gas source.
Another aspect of the invention provides a method of monitoring components of a gas mixture in a gas source, the components having infrared absorption wavelengths which are characteristic of those components, the method comprising the steps of: (a) providing a gas cell in connection with the gas source; (b) receiving a sample of a gas mixture into the cell from the gas source, the pressure of the sample in the cell being reduced relative to the pressure of the source; (c) transmitting infrared radiation through the cell; and (d) measuring the transmitted infrared radiation to determine the infrared radiation absorbance of one or more components of the gas mixture. The method may be implemented using the device of the first aspect.
The method may further comprise, before steps (b) to (d), the steps of: (A) evacuating or flushing the gas cell; (B) transmitting infrared radiation through the cell; and (C) measuring the transmitted infrared radiation to measure a background infrared absorbance for the cell.
Thereafter, the method may further comprise the step (e) of calculating from the absorbances measured at steps (C) and (d) any one or combination of: (i) an infrared absorption spectrum for the sample, (ii) the presence of components in the gas mixture and (iii) the relative amounts of components in the gas mixture. Steps (A), (b), (c), (d) and (e) may be performed repeatedly. Steps (B) and (C) may also be performed repeatedly, for example at the same repetition rate as steps (A), (b), (c), (d) and (e), or at a lower repetition rate.
Preferably, at step (A), the cell is evacuated.
Flushing is an alternative to evacuation, e.g. using a non-infrared absorbing gas such as N2. However, flushing reduces the expansion cooling advantage. Further, it may be desirable to measure a background spectrum after every flush to verify removal of the previous sample. Also, the supply of consumable flushing gas adds to the cost of the method.
Typically, the pressure of the source is 10 bar or more. More typically, the pressure of the source is 20 bar or more, or 40 bar or more.
Typically, the pressure of the sample in the cell is reduced to atmospheric pressure or lower.
The method may comprise a step of cooling the sample relative to the temperature of the source.
Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows low pressure (0.13 bar, 13 kPa) infrared absorption spectra of methane, ethane, and propane; Figure 2 shows schematically an embodiment of a gas mixture monitoring device according to the present invention; and Figure 3 shows schematically an embodiment of a further gas mixture monitoring device according to the present invention.
Figure 1 shows low pressure (0.13 bar, 13 kPa) infrared absorption spectra of methane, ethane, and propane, which are three typical components of natural gas.
However, at the approximately 45 bar (4.5 MPa) gas delivery pressure for a gas turbine engine, the spectral lines would be much broader and fine detail would be lost, making it difficult, if not impossible, to distinguish between the individual molecules from a spectrum of the gas.
Figure 2 shows schematically an embodiment of a gas mixture monitoring device 1 according to the present invention.
The device 1 is connected to a gas delivery pipe 2 of a gas turbine engine, a sampling probe pipe 3 joining the delivery pipe to one end of an elongate gas cell 4. A gas sample enters the cell via the probe pipe, is analysed by infrared spectroscopy (as described below), and then exits the cell via outlet passage 6 at the other end of the cell.
In order that the spectral lines of the components of the gas can be resolved by infrared spectroscopy, the pressure of the sample in the gas cell 4 is reduced relative to the line pressure in the delivery pipe 2. To achieve the pressure reduction, the gas is sampled periodically from the pipe rather than continuously, a fast acting valve 5 at the entrance to the cell regulating the flow of gas into the cell.
The outlet passage 6 of the cell 4 is connected to a vacuum pump (not shown) which evacuates the cell in readiness for the reception of a gas sample into the cell.
Preliminary to receiving the sample, valve 7 in the outlet
passage is closed and a background spectrum of the
evacuated cell recorded. The fast acting valve 5 then briefly opens and a sample of gas enters the cell. The gas sample expands in the cell, which reduces its pressure, and also produces expansion cooling. The reduced pressure decreases the spectral linewidths of the gas, while the expansion cooling helps to simplify subsequent analysis of the absorption spectrum by reducing the number of populated molecular energy levels. If the infrared absorption measurement cannot be made in a short time, the cell can be insulated, or actively cooled, so that the gas sample is maintained, in thermal equilibrium, at a low temperature and pressure while slow scan absorption measurements (which may be required to detect minor components of the gas mixture) are made. When the measurements are completed, valve 7 opens and the cell is evacuated before the measurement cycle repeats.
The background spectrum provides a baseline against which the amount of absorption by a component in the gas mixture is indicated by the size of the absorption peak or peaks for that component in the spectrum obtained when the sample of gas mixture is in the cell. The relative absorptions of the components in the gas mixture then provide an indication of the relative amounts of those components in the mixture.
The device 1 may have a pressure sensor (not shown) and/or a temperature sensor (not shown) in the cell 4 to allow more accurate determination, from the infrared absorptions, of the relative amounts of the components.
The background spectrum need not be recorded before every absorption spectrum measurement, particularly if a pressure sensor in the cell verifies that it has been evacuated.
However, it may still be necessary to record background spectra periodically, e.g. to compensate for any changes in the infrared source, optical components (e.g. windows) or detector characteristics.
The fast acting valve 5 can be of the type used for pulsed molecular beam generation. In the closed state of the valve, a metal strip blocks an orifice. To open the valve, a large pulse of electric current is passed through the metal strip. The current heats the strip, which distorts its shape allowing gas to pass through the orifice. The metal is then rapidly cooled by the flow of gas, closing the valve again.
The background spectrum and the absorption spectrum for the gas sample can be obtained by dispersive or Fourier Transform Infrared (FTIR) Spectroscopy. An infrared radiation source 8, such as a globar, delivers multi-wavelength infrared radiation into the cell 4 through an infrared transmitting window at one end of the cell. The radiation is transmitted through the sample to exit the cell at another infrared transmitting window at the other end of the cell. For dispersive spectroscopy, it then enters a combined spectrometer and infrared detector 9.
The spectrometer splits the multi-wavelength infrared radiation into individual wavelength bins which are separately measured by the detector. For FTIR it passes through a scanning interferometer to a single element detector. The absorption spectrum can then be obtained from the Fourier transform of the temporal profile of intensity at the detector.
Another option is to use an infrared radiation source which produces single wavelength radiation, e.g. the source may comprise one or more diode lasers. With such an approach the use of a spectrometer can be avoided.
Infrared diode lasers (e.g. quantum cascade lasers in the mid-infrared or distributed feedback lasers in the near-infrared) have narrow wavelength tuning ranges, and generally one laser is required for each molecule analysed.
Lasers can be selected to coincide with spectral lines of particular molecules expected to be significant components of the gas, and where there is little or no interference between the lines. The low pressure in the cell helps to avoid interference between the lines. The laser light can be delivered via a single optical fibre and the temporally resolved detector output measured to distinguish the absorption by particular molecules.
Figure 3 shows schematically a further embodiment of a gas mixture monitoring device 1' according to the present invention which makes use of diode lasers. Identical features in the embodiments of Figures 2 and 3 retain the same reference numbers. In place of the multi-wavelength infrared radiation source 8, narrow band infrared lasers lOa, lOb, and lOc are used as the radiation source. Each laser is tuned to an isolated absorption line of a respective component of interest. The outputs of the lasers are coupled into a single delivery fibre 11 and the lasers are pulsed so that the light from each laser is separated in time from the others, as indicated schematically at 12.
A collection fibre 13 receives the transmitted infrared radiation and delivers it to an infrared detector 9', which differs from the infrared detector 9 in not requiring a spectrometer. When the laser lOa is pulsed on' and the cell is evacuated, the detector measures a signal proportional to the output of the laser lOa. When there is gas in the cell, this signal is attenuated by the absorption of the component to which the laser lOa is tuned. The absorption by that component can thus be determined from the two measurements. The absorptions by the respective components to which lasers lOb and lOc are tuned are measured in a similar manner, and the relative absorptions of the three components thus obtained. In this way the three components can be monitored in phase with the pulsing of the three lasers, as indicated schematically at 14.
The further embodiment of Figure 3 also has a processor 15, which determines from the infrared radiation measured at the detector 9' the relative amounts of the three components in the gas mixture. The processor sends a signal passing this information (for example in the form of a calorific value of the gas mixture) to an engine control system 16, which can then control the combustion or other operating conditions of the gas turbine engine which uses the gas mixture as fuel. Alternatively, the processor can pass the information to an engine operator.
While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. For example, the invention could be applied to monitoring any high pressure gas flow, such as feed to a chemical process reactor, e.g. syngas feed to a reactor for Fischer-Tropsch synthesis of synthetic liquid fuel. The configuration of a monitoring device for such an application could be substantially identical to the devices described above in relation to Figures 2 and 3. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

Claims (18)

  1. CLAIMS1. A device (1) for monitoring components of a gas mixture having: a gas cell (4) for receiving a sample of the gas mixture, an infrared radiation source (8; lOa, lOb, lOc) which delivers infrared radiation into the cell for transmission through the sample, the transmitted infrared radiation being absorbed by components of the gas mixture at absorption wavelengths which are characteristic of those components, and an infrared detector (9; 9') which measures the transmitted infrared radiation, thereby enabling the monitoring of components of the gas mixture in the sample; wherein the device s connectable to a gas source (2) from which the cell receives the sample, and the device further has a system for reducing the pressure of the sample in the cell.
  2. 2. A device according to claim 1, wherein the system for reducing the pressure includes means (6, 7) for evacuating the cell.
  3. 3. A device according to claim 1 or 2, wherein the pressure in the cell is lower than the pressure of the source, and the system for reducing the pressure includes a valve (5) which controls the flow of gas from the source to the cell, the valve being adapted to be opened and closed at sufficiently high speed such that the sample of gas received by the cell from the source on opening and closing of the valve experiences a reduction in pressure.
  4. 4. A device according to any one of the previous claims, which further includes means for cooling the gas cell relative to the temperature of the source.
  5. 5. A device according to any one of the previous claims, wherein the pressure of the source is 10 bar or more.
  6. 6. A device according to any one of the previous claims, wherein the pressure of the sample in the cell is reduced to atmospheric pressure or lower.
  7. 7. A device according to any one of the previous claims, wherein: the infrared radiation source delivers multi-wavelength infrared radiation into the cell, and the device further has a spectrometer between the gas cell and the infrared detector.
  8. 8. A device according to any one of claims 1 to 6, wherein: the infrared radiation source delivers at any one time single wavelength infrared radiation into the cell.
  9. 9. A device according to claim 8, wherein: the infrared radiation source delivers successive pulses (12) of single wavelength infrared radiation into the cell, each pulse having a different wavelength.
  10. 10. A device according to any one of the previous claims, wherein the system further has: a processor which determines from the measured infrared radiation an infrared absorption spectrum, and a display which displays the infrared absorption spectrum.
  11. 11. A device according to any one of the previous claims, wherein the system further has: a processor (15) which determines from the measured infrared radiation the presence of components in the gas mixture and/or the relative amounts of components in the gas mixture.
  12. 12. A device according to any one of the previous claims which is connected to the gas source.
  13. 13. An engine having the device of claim 12 as dependent on claim 11, wherein the gas source supplies fuel to the engine, and the engine has an engine control system (16) which is in communication with the processor, the engine control system controlling the combustion of the fuel by the engine depending on which components are present in the gas mixture and/or on the relative amounts of components in the gas mixture as determined by the processor.
  14. 14. Use of the device of any one of claims 1 to 12 for monitoring components of a gas mixture in a gas source.
  15. 15. A method of monitoring components of a gas mixture in a gas source, the components having infrared absorption wavelengths which are characteristic of those components, the method comprising the steps of: (a) providing a gas cell in connection with the gas source; (b) receiving a sample of a gas mixture into the cell from the gas source, the pressure of the sample in the cell being reduced relative to the pressure of the source; (c) transmitting infrared radiation through the cell; and (d) measuring the transmitted infrared radiation to determine the infrared radiation absorbance of one or more components of the gas mixture.
  16. 16. A method according to claim 15, further comprising, before steps (b) to (d), the steps of: (A) evacuating or flushing the gas cell; (B) transmitting infrared radiation through the cell; and (C) measuring the transmitted infrared radiation to measure a background infrared absorbance for the cell; wherein the method further comprises the step of: (e) calculating from the absorbances measured at steps (C) and (d) any one or combination of: (i) an infrared absorption spectrum for the sample, (ii) the presence of components in the gas mixture and (iii) the relative amounts of components in the gas mixture.
  17. 17. A method according to claim 16, wherein steps (A), (b), (c), (d) and (e) are performed repeatedly.
  18. 18. A device for monitoring components of a gas mixture as any one herein described with reference to and/or as shown in Figures 2 and 3.
GB0822350A 2008-12-09 2008-12-09 Monitoring of components of a gas mixture in a reduced pressure environment Withdrawn GB2466181A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015095315A1 (en) * 2013-12-20 2015-06-25 General Electric Company Method and system for detecting moisture in a process gas involving cross interference
WO2017220189A1 (en) * 2016-06-25 2017-12-28 Hydac Electronic Gmbh Method and device for monitoring the quality of gaseous media

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01109243A (en) * 1987-10-21 1989-04-26 Ishikawajima Harima Heavy Ind Co Ltd Gas analyzing and measuring instrument
JPH10221253A (en) * 1997-02-07 1998-08-21 Fuji Electric Co Ltd Infrared gas analyzer and gas concentration measuring method
US5821537A (en) * 1994-03-25 1998-10-13 Nippon Sanso Corporation Infrared spectroscopic analysis method for gases and device employing the method therein
US6439040B1 (en) * 1997-08-25 2002-08-27 Wissenschaftliche Wekstatt Fur Umweltmesstechnik Gmbh Device for analyzing exhaust emissions from motor vehicles
US20030080295A1 (en) * 2001-08-16 2003-05-01 Webber Michael E. Gas sensor for ammonia, carbon dioxide and water

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01109243A (en) * 1987-10-21 1989-04-26 Ishikawajima Harima Heavy Ind Co Ltd Gas analyzing and measuring instrument
US5821537A (en) * 1994-03-25 1998-10-13 Nippon Sanso Corporation Infrared spectroscopic analysis method for gases and device employing the method therein
JPH10221253A (en) * 1997-02-07 1998-08-21 Fuji Electric Co Ltd Infrared gas analyzer and gas concentration measuring method
US6439040B1 (en) * 1997-08-25 2002-08-27 Wissenschaftliche Wekstatt Fur Umweltmesstechnik Gmbh Device for analyzing exhaust emissions from motor vehicles
US20030080295A1 (en) * 2001-08-16 2003-05-01 Webber Michael E. Gas sensor for ammonia, carbon dioxide and water

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015095315A1 (en) * 2013-12-20 2015-06-25 General Electric Company Method and system for detecting moisture in a process gas involving cross interference
US9194797B2 (en) 2013-12-20 2015-11-24 General Electric Company Method and system for detecting moisture in a process gas involving cross interference
WO2017220189A1 (en) * 2016-06-25 2017-12-28 Hydac Electronic Gmbh Method and device for monitoring the quality of gaseous media
US11060971B2 (en) 2016-06-25 2021-07-13 Hydac Electronic Gmbh Method and device for monitoring the quality of gaseous media

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