6 Maintenance
6-2. Calibration method
- 24 -
<Span Adjustment (AIR adjustment)>
Adjust the reading to “20.9” at the indicator/alarm unit side under the condition that no gas is present
around the detection point.
If a gas is present around the detection point, collect fresh air in a gas sampling bag or the like and release
it at the detection point for a certain time or so before starting the AIR adjustment.
①
Fill the gas sampling bag with calibration gas (fresh air for the oxygen deficiency alarm or gas with a
concentration in the region of the alarm setpoint for all other cases).
However, for simplified calibration, you can use ambient air as 20.9 vol% calibration gas after
confirming that the ambient air pressure is 1 atmosphere (1,000 hPa ±50 hPa) and that concentrations
of impurities are negligibly low relative to the calibration gas concentration.
②
After the gas is introduced and the oxygen concentration reading in the indicator/alarm section is
stabilized, the indicator/alarm section will be adjusted so that this indication reading indicates the
calibration gas concentration reading.
③
Stop the calibration gas flow and verify that the oxygen concentration reading is 20.9 vol%. (Span
adjustment complete)
CAUTION
•
Before starting the span adjustment (AIR adjustment), provide the detector with the calibration
gas and wait until the reading is stabilized.
WARNING
When the span adjustment (AIR adjustment) is performed in the atmosphere, check the
atmosphere for freshness before beginning the adjustment. If interference gases exist, the
adjustment cannot be performed properly, thus leading to dangers when the gas leaks.
Summary of Contents for GD-1DOX-AS
Page 1: ...PT2E 2880 Fixed type Oxygen Detector Head GD 1DOX AS Operating Manual PT2 183...
Page 9: ......
Page 10: ......
Page 15: ......
Page 16: ......
Page 18: ......
Page 22: ......
Page 25: ......
Page 32: ......
Page 34: ...Manual Log Rev Amendment Issue data 0 First issue PT2 2880 1 31 2022...