Non-Dispersive Infrared Gas Analyzer

• US 20080011952A1
• Filed: 06/09/2005
• Published: 01/17/2008
• Est. Priority Date: 06/30/2004
• Status: Abandoned Application

• Current Assignee: ABB Patent GmbH (ABB Limited)
• Original Assignee: ABB Patent GmbH (ABB Limited)
• Inventors: Fabinski, Walter, Rathke, Carsten
• Application Number:
  US11/630,919
• Publication Number:
  US 20080011952A1
• Time in Patent Office: Days
• US Class Current: 250/344
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 21/37 using pneumatic detection opto-acoustic detection G01N21/1702
• CPC Class Codes: G01N 21/61 Non-dispersive gas analysers G01N21/3504 takes precedence

Abstract

The invention relates to a non-dispersive infrared gas analyzer (1) for identifying a test gas containing a number of gas constituents, comprising a radiation source (2), a modulating device (3), a measuring cell (4), which has a measuring chamber (4a) and a comparing chamber (4b), and comprising an optopneumatic detector unit (5) that has a first detector (5a), which, for measuring gas constituent A, is filled with gas constituent A, and has a second detector (5b), which is situated behind the first detector (5a) and which, for measuring gas constituent B, is filled with the isotope B* thereof.

Claims

1. A non-dispersive infrared gas analyzer (1) for determining a measurement gas containing a plurality of gas components, comprising a radiation source (2), a modulation device (3), a measuring cuvette (4) comprising a measuring chamber (4a) and a comparison chamber (4b) and an optopneumatic detector unit (5) having a first detector (5a), which is filled with the gas component A for measurement of the gas component A, and a second detector (5b), which is arranged behind the first detector (5a) and which, for measurement of the gas component B, is filled with its isotope B*.

2. The non-dispersive infrared gas analyzer (1) as claimed in claim 1, characterized in that the first and second detectors (5a, 5b) have windows (6) that are radiation-transmissive transversely with respect to the radiation direction.

3. The non-dispersive infrared gas analyzer (1) as claimed in claim 1 or 2, characterized in that the first and/or the second detector (5a, 5b) are/is formed as two-layer detector.

4. The non-dispersive infrared gas analyzer (1) as claimed in one of the preceding claims, characterized in that a calibration apparatus can be arranged between the measuring cuvette (4) and the detector unit (5).

5. The non-dispersive infrared gas analyzer (1) as claimed in claim 4, characterized in that the calibration apparatus comprises a calibration cuvette filled with a gas mixture composed of A and B*.

6. The non-dispersive infrared gas analyzer (1) as claimed in one of the preceding claims, characterized in that the first and second detectors (5a, 5b) are interchangeable.

7. The non-dispersive infrared gas analyzer (1) as claimed in one of the preceding claims, characterized in that the modulation device (3) interrupts the radiation of the radiation source (2) in antiphase.

8. The non-dispersive infrared gas analyzer (1) as claimed in one of the preceding claims, characterized in that the modulation device (3) has a chopper disk.

9. The non-dispersive infrared gas analyzer (1) as claimed in one of the preceding claims, characterized in that a filter apparatus (7) can be arranged between the measuring cuvette (4) and the detector unit (5).

10. The non-dispersive infrared gas analyzer (1) as claimed in claim 9, characterized in that the filter apparatus (7) comprises a filter cuvette (7) filled with the gas component B.

11. The non-dispersive infrared gas analyzer (1) as claimed in claim 10, characterized in that the filter cuvette (7) is formed integrally with the measuring cuvette (4).

12. The non-dispersive infrared gas analyzer (1) as claimed in one of the preceding claims, characterized in that the two-layer detector (5a, 5b) comprises a measuring detector chamber (8) and a comparison detector chamber (9) arranged one behind another in the radiation direction.

13. The non-dispersive infrared gas analyzer (1) as claimed in claim 12, characterized in that the comparison detector chamber (9) and the measuring detector chamber (8) are pneumatically connected to one another.

14. The non-dispersive infrared gas analyzer (1) as claimed in one of the preceding claims, characterized in that the measuring cuvette (4) has an inner wall area formed with a metal layer.