Metek 920, Operator'S Manual With Essential Health And Safety Requirements

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3-40 | Model 920 Multi-Gas Analyzer
Sample System Leak Check
The analyzer has been checked at the factory for pressure leaks. However,
fittings can loosen during transport, and the Sample, Vent (if used),
Instrument Air, and Calibration gas lines are installed on-site. Therefore,
the entire sample system should be checked for leaks before any sample
gas is introduced into the system for the first time or following the re-
placement of any lines/fittings or Measuring Cell parts.
Hazardous Locations
Before proceeding, test the area around the analyzer for hazardous
gases and proceed only when the area is found to be safe.
Preventing leaks in the sample system is critical to ensure proper
analyzer operation. If sample gas migrates into the Optical Bench
Assembly or Reflector Block due to a leak in the Measuring Cell, the
optics will become damaged and most likely require replacement. Most
leaks are preventable with the regular replacement of the Measuring
Cell o-rings.
To leak check the sample system:
1. With the analyzer powered up, open the Aspirator Drive Air
Regulator to allow instrument air into the sample system.
2. Close the isolation valves on the sample gas extraction equipment (or
cap the Sample Line) and on the Vent Line Valve, if used (or discon-
nect the Vent Pipe at the Vent port in the Analyzer Oven and tempo-
rarily install a cap).
3. Use the Aspirator Drive Air Regulator to increase the Instrument Air
pressure to 70 KPAG (10 PSIG).
To avoid damaging the pressure transducer, do not set the pressure
higher than 105 KPAG (15 PSIG).
4. View the CellP (Measuring Cell Pressure) screen and record the nu-
meric value displayed. This value is the absolute pressure reading in
mmHg (or "Hg).
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CAUTION
!
CAUTION
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WARNING
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(CellP) RUN
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