Selective gas detecting apparatus
First Claim
1. A selective gas detecting apparatus for determining a concentration and type or average type of hydrocarbon gas in a gas sample based upon absorption of infrared radiation by the gas sample, comprising:
- means for passing infrared radiation through the gas sample, infrared radiation detecting means for detecting infrared radiation passed through the gas sample and producing in a first signal channel a first measurement signal indicative of a first wavelength absorbed by the gas sample, and producing in a second signal channel a second measurement signal indicative of a second wavelength absorbed by the gas sample, processing circuit means including first circuit means responsive to said first measurement signal for providing a first output signal corresponding to a first total concentration of hydrocarbons in the gas sample, second circuit means responsive to said second measurement signal for providing a second output signal corresponding to a second total concentration of hydrocarbons in the gas sample, ratio determining means responsive to said first and second output signals for providing a ratio signal corresponding to the ratio of said first and second output signals, said ratio signal being indicative of the type or average type of hydrocarbon gas, and display means responsive to said first output signal and said ratio signal for providing an indication of the concentration and type or average type of hydrocarbon gas in the gas sample, respectively.
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Accused Products
Abstract
A selective gas detecting apparatus for determining the concentration and type of hydrocarbon gas in a gas sample based upon absorption of infrared radiation by the gas sample, the apparatus having two infrared radiation absorption channels with the wavelengths for measurement selected so that one channel at 3.2 microns provides an output signal corresponding to approximately the sum of all hydrocarbons in the gas sample which signal is displayed as an indication of concentration of hydrocarbon gas in the gas sample, and the other channel at 3.4 microns, after essentially being ratioed to the 3.2 micron channel output provides an output signal representative of the type or average type of hydrocarbon in the gas sample, and the ratio of the signal in the two channels is displayed as an indication of the type of hydrocarbon in the gas sample.
29 Citations
20 Claims
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1. A selective gas detecting apparatus for determining a concentration and type or average type of hydrocarbon gas in a gas sample based upon absorption of infrared radiation by the gas sample, comprising:
- means for passing infrared radiation through the gas sample, infrared radiation detecting means for detecting infrared radiation passed through the gas sample and producing in a first signal channel a first measurement signal indicative of a first wavelength absorbed by the gas sample, and producing in a second signal channel a second measurement signal indicative of a second wavelength absorbed by the gas sample, processing circuit means including first circuit means responsive to said first measurement signal for providing a first output signal corresponding to a first total concentration of hydrocarbons in the gas sample, second circuit means responsive to said second measurement signal for providing a second output signal corresponding to a second total concentration of hydrocarbons in the gas sample, ratio determining means responsive to said first and second output signals for providing a ratio signal corresponding to the ratio of said first and second output signals, said ratio signal being indicative of the type or average type of hydrocarbon gas, and display means responsive to said first output signal and said ratio signal for providing an indication of the concentration and type or average type of hydrocarbon gas in the gas sample, respectively.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A selective gas detecting apparatus for determining the concentration and type or average type of hydrocarbon gas in a gas sample based upon absorption of infrared radiation by the gas sample comprising:
- means for passing infrared radiation through the gas sample, infrared detecting means for detecting infrared radiation passed through the gas sample including a first infrared detector producing a first detection signal indicative of a first wavelength absorbed by the gas sample, a second infrared detector producing a second detection signal indicative of a second wavelength absorbed by the gas sample, and a reference infrared detector producing a reference signal indicative of a third wavelength absorbed by the gas sample, first signal combining circuit means for combining said reference signal with said first detection signal to produce a first measurement signal indicative of said first wavelength absorbed by the gas sample, second signal combining circuit means for combining said reference signal with said second detection to produce a second measurement signal indicative of said second wavelength absorbed by the gas sample, processing circuit means including first circuit means responsive to said first measurement signal for providing a first output signal corresponding to a first total concentration of hydrocarbons in the gas sample, second circuit means responsive to said second measurement signal for providing a second output signal corresponding to a second total concentration of hydrocarbons in the gas sample, ratio determining means responsive to said first and second output signals for providing a ratio signal corresponding to the ratio of said first and second output signals, said ratio signal being indicative of the type or average type of hydrocarbon gas, and display means responsive to said second output signal and said ratio signal for providing an indication of the concentration and type or average type of hydrocarbon gas in the gas sample, respectively.
- View Dependent Claims (15, 16, 17, 18, 19)
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20. A method of determining a concentration and type or average type of hydrocarbon gas in a gas sample comprising:
- passing infrared radiation through the gas sample, detecting infrared radiation passed through the gas sample, producing in a first signal channel a first measurement signal indicative of a first wavelength absorbed by the gas sample and corresponding to a first total concentration of hydrocarbons in the gas sample, producing in a second signal channel a second measurement signal indicative of a second wavelength absorbed by the gas sample and corresponding to a second total concentration of hydrocarbons in the gas sample, obtaining a ratio of the first and second measurement signals to produce a ratio signal indicative of the type or average of hydrocarbon gas and applying the second measurement signal and the ratio signal to first and second analog meters to provide an indication of the concentration and type or average of hydrocarbon gas, respectively, in the gas sample.
Specification