公开(公告)号：EP1831671A2

公开(公告)日：2007-09-12

申请号：EP05852281.4

申请日：2005-11-29

Applicant: Honeywell International, Inc.

Inventor： TICE, Lee

IPC: G01N21/61

CPC classification number: G01N21/15 ,  G01N21/314 ,  G01N21/3504 ,  G01N2021/158 ,  G01N2021/3137 ,  G01N2021/3166 ,  G01N2201/1214 ,  G01N2201/1273

Abstract: A non-dispersive infra-red gas detector includes a condensation eliminating heater. The heater can be intermittently energized in response to a signal received from an environmental sensor. Signals from a gas sensor in the detector can be processed to determine when to energize the heater.

公开(公告)号：EP0253872A4

公开(公告)日：1990-04-10

申请号：EP87900946

申请日：1987-01-09

Applicant: ANDROS ANALYZERS INC

Inventor： PASSARO ROBERT EUGENE ,  ROGERS RAYMOND EARL ,  GRIFFITH CRAIG JAMES

IPC: G01J1/44 ,  G01N21/27 ,  G01N21/31 ,  G01N21/35

CPC classification number: G01N21/274 ,  G01N21/3504 ,  G01N2021/3159 ,  G01N2021/3166 ,  G01N2201/126 ,  G01N2201/1273 ,  G01N2201/12769

Abstract: Automatic zeroing apparatus zeroes an infrared gas analyzer automatically upon the occurrence of preselected conditions to indicate zero in the absence of absorption of infrared radiation by a gas mixture being analyzed. The gas analyzer has a sample cell (11) for containing a gas mixture to be analyzed. Infrared radiation directed through the sample cell (11) is detected at a preselected wavelength to produce a detection signal. A signal processor outputs a signal systematically related to the difference between the detection signal and a reference signal. For zeroing the sample cell (11) is filled with gas substantially nonabsorbent of infrared radiation at the respective characteristic wavelength. A comparator produces an error signal when the output signal differs from zero. A gain control (DAC 21) automatically controls the signal level of the detection signal to reduce the output signal substantially to zero with the nonabsorbent gas filling the sample cell (11). The preselected conditions may include the passage of a predetermined time and a temperature drift beyond a predetermined limit.