Apparatus and method for controlling atmospheres in heat treating of metals
First Claim
1. An absorption gas analyzer for measuring a concentration of at least a component gas in a sample gas comprising:
- a main absorption cell for containing the sample gas at a predetermined temperature and a predetermined pressure for measurement therein;
at least an electromagnetic radiation source for providing electromagnetic radiation in at least a predetermined narrow wavelength band, the predetermined narrow wavelength band being within a wavelength range of a predetermined absorption band of each of the at least a component gas, the electromagnetic radiation for being transmitted through the main absorption cell;
a reflecting device disposed for reflecting the electromagnetic radiation after transmission through the main absorption cell such that the electromagnetic radiation is transmitted again therethrough; and
, at least a detector for detecting the electromagnetic radiation after the second transmission through the main absorption cell and for providing at least an intensity signal in dependence upon the concentration of the at least a component gas, the at least a detector being placed at a predetermined distance from the reflecting device with the predetermined distance including a predetermined defocusing distance.
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Accused Products
Abstract
The present invention relates to an absorption gas analyzer for measuring a concentration of at least a component gas in a sample gas. The absorption gas analyzer comprises a main absorption cell for containing the sample gas for measurement therein. At least a narrow band emitter emits electromagnetic radiation in at least a predetermined narrow wavelength band which is transmitted through the main absorption cell. A reflecting device is disposed for reflecting the electromagnetic radiation after transmission through the main absorption cell such that the electromagnetic radiation is transmitted again therethrough. At least a detector detect the electromagnetic radiation and provide at least an intensity signal in dependence upon the concentration of the at least a component gas. The absorption gas analyzer enables simultaneous determination of concentration of a plurality of individual component gases with a high level of accuracy.
33 Citations
51 Claims
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1. An absorption gas analyzer for measuring a concentration of at least a component gas in a sample gas comprising:
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a main absorption cell for containing the sample gas at a predetermined temperature and a predetermined pressure for measurement therein;
at least an electromagnetic radiation source for providing electromagnetic radiation in at least a predetermined narrow wavelength band, the predetermined narrow wavelength band being within a wavelength range of a predetermined absorption band of each of the at least a component gas, the electromagnetic radiation for being transmitted through the main absorption cell;
a reflecting device disposed for reflecting the electromagnetic radiation after transmission through the main absorption cell such that the electromagnetic radiation is transmitted again therethrough; and
,at least a detector for detecting the electromagnetic radiation after the second transmission through the main absorption cell and for providing at least an intensity signal in dependence upon the concentration of the at least a component gas, the at least a detector being placed at a predetermined distance from the reflecting device with the predetermined distance including a predetermined defocusing distance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. An absorption gas analyzer for measuring a concentration of at least a component gas in a sample gas comprising:
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a main absorption cell for containing the sample gas at a predetermined temperature and a predetermined pressure for measurement therein;
at least an electromagnetic radiation source for providing electromagnetic radiation in at least a predetermined narrow wavelength band, the predetermined narrow wavelength band being within a wavelength range of a predetermined absorption band of the at least a component gas, the electromagnetic radiation for being transmitted through the main absorption cell;
an interfering gas cell containing an interfering gas comprising an absorption band which is partially overlapping the wavelength band of one of the at least a narrow band emitter;
a reflecting device disposed for reflecting the electromagnetic radiation after transmission through the main absorption cell such that the electromagnetic radiation is transmitted again therethrough; and
,at least a detector for detecting the electromagnetic radiation after the second transmission through the main absorption cell and for providing at least an intensity signal in dependence upon the concentration of the at least a component gas. - View Dependent Claims (23, 24, 25, 26, 27)
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28. A method for measuring a concentration of at least a component gas in a sample gas representative of an atmosphere in a processing apparatus comprising:
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a) providing in a main absorption cell the sample gas at a predetermined temperature and a predetermined pressure for measurement therein;
b) transmitting electromagnetic radiation through the main absorption cell, the electromagnetic radiation being provided from at least an electromagnetic radiation source in at least a predetermined narrow wavelength band within a wavelength range of a predetermined absorption band of the at least a component gas;
c) reflecting the electromagnetic radiation using a reflecting device;
d) transmitting the reflected electromagnetic radiation through the main absorption cell; and
,e) detecting the electromagnetic radiation after the second transmission through the main absorption cell at a predetermined distance from the reflecting device with the predetermined distance including a predetermined defocusing distance and providing at least an intensity signal in dependence upon the concentration of the at least a component gas. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46)
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47. A system for controlling composition of a heat treating atmosphere comprising:
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a main absorption cell for containing the sample gas at a predetermined temperature and a predetermined pressure for measurement therein;
an inlet and an outlet in fluid communication with the main absorption cell, the inlet for being in fluid communication with a heat treating apparatus for receiving a sample gas representative of the heat treating atmosphere therefrom;
at least an electromagnetic radiation source for providing electromagnetic radiation in at least a predetermined narrow wavelength band, the predetermined narrow wavelength band being within a wavelength range of a predetermined absorption band of each of at least a component gas in the sample gas, the electromagnetic radiation for being transmitted through the main absorption cell;
a reflecting device disposed for reflecting the electromagnetic radiation after transmission through the main absorption cell such that the electromagnetic radiation is transmitted again therethrough;
at least a detector for detecting the electromagnetic radiation after the second transmission through the main absorption cell and for providing at least an intensity signal in dependence upon the concentration of the at least a component gas;
a processor in signal communication with the at least a detector for determining at least a heat treating potential in dependence upon data indicative of the at least an intensity signal and for providing a gas inflow control signal in dependence upon the at least a heat treating potential; and
,a gas inflow control communication link for providing the gas inflow control signal to a gas inflow controller of the heat treating apparatus. - View Dependent Claims (48, 49, 50, 51)
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Specification