GAS DETECTOR UNIT

• US 3,832,548 A
• Filed: 10/18/1972
• Issued: 08/27/1974
• Est. Priority Date: 10/18/1972
• Status: Expired due to Term

• Current Assignee: Stanley Wallack
• Original Assignee: Stanley Wallack
• Inventors: Wallack, Stanley
• Primary Examiner(s): Lindquist, William F.
• Application Number:
  US05/298,638
• Time in Patent Office: 678 Days
• Field of Search: 250/43.5R,86
• US Class Current: 250/343
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis

Abstract

An infrared detector for detecting and quantitatively measuring a plurality of select gases in a gaseous medium which includes an infrared (IR) source; a sample cell, continuous or segmented filter means which selectively passes IR waves of the near and intermediate region at varying positions which correspond to a predetermined gas; detector means; means for moving said filter means in conjunction with said sample cell and detector means, and read-out means for each of said gases is described. The described device is compact, utilizes relatively few components, is simple and economical to operate, while providing rapid and accurate readings of the concentration of each of the plurality of gases. The qualitative and quantitative monitoring of gases can be selectively applied to any IR absorbing gas in combination with any other IR absorbing gas.

Claims

1. A detecting and measuring device for detecting the presence or absence of, and quantitatively measuring for a plurality of gases in a gaseous medium comprising in combination a single infrared source, a single sample cell for retaining a sample aligned to receive IR waves in a single path from said source, filter means having a plurality of positions where only IR waves of select wavelength pass, said filter means aligned to receive IR waves in said single path from said source;

IR detector means aligned to receive IR waves passing through said filter means and sample cell, and means for moving said filter to a first predetermined position for detecting a first gas and then to a predetermined reference position to quantitatively determine the amount of detected gas in said sample cell, and thereafter moving said filter through a plurality of predetermined positions on said filter means to detect and quantitatively measure for a plurality of gases in said sample cell, said moving means including means for stopping said filter means at each position; and

readout means for the gas and concentration of said gas.

2. The device of claim 1 wherein said filter means comprises a filter which will pass IR waves at any length throughout a given range.

3. The device of claim 2 wherein said filter means is of circular configuration.

4. The detector of claim 1 including modulating means between said IR source and sample cell.

5. The device of claim 4 wherein said modulating means are mechanical means.

6. The device of claim 5 wherein said mechanical means is a chopper wheel.

7. The device of claim 1 wherein the read-out means includes memory means and signal sorter means.

8. The device of claim 7 wherein said read-out includes continuous printer means.

9. The device of claim 1 including programming means for continuously moving said filter to said first position for detecting a first gas;

to said reference position to quantitatively determine the amount of said first detected gas and thereafter through a plurality of positions on said filter means to detect and quantitatively measure for a plurality of gases.

10. A method for detecting the presence or absence of and quantitatively measuring for a plurality of gases in a gaseous medium comprising projecting IR waves in a single path from a single infrared source through filter means and a single sample cell retaining a sample of gaseous medium from which gases are to be detected and, if present, quantitatively measured, said filter means having a plurality of positions where only IR waves of select wavelengths pass, detecting the wavelengths which pass through said sample and filter means at each of said positions on said filter means, said method including continuously moving said filter from a first predetermined position for detecting a first gas;

to a predetermined reference position for said first gas to compare the IR waves which have passed through at said first position and determine the quantity of said first gas, and sequentially repeating the steps until each of the plurality of gases has been detected and measured.