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Operation
ALTAIR io360
US
6.2.4
Exceed High and Low of Sensor
When a gas reading exceeds the full scale range of the sensor, the detector displays can "XXX" or "+++" in
place of the actual reading.
When a gas reading falls below a defined under-range threshold, the detector displays " ---" in place of the
actual reading.
For the combustible sensor to return to normal operation after the locked alarm, the detector must pass
calibration. The over-range or under-range of a sensor will clear when the sensor reads gas reading within
the normal range, i.e. no action is needed from the user.
6.3
Monitoring Oxygen Concentration
The detector monitors the oxygen concentration in ambient air. The alarm set points can be set to activate
on two different conditions:
• Enriched - oxygen concentration > 20.8 % or
• Deficient - oxygen concentration < 19.5 %.
While the detector can detect up to 30 % oxygen in the ambient air, it is approved for use only up to 21 %
oxygen-content.
For combustible sensors, the sensor reading is in in locked alarm.
The sensor reading is in over-range.
The sensor reading is in under-range.
The LOW alarm (oxygen deficient) is non-latching and will automatically reset when the O
2
concentration rises above the LOW set point.
If the alarm condition still exists, the button only silences the alarm for five seconds.
False oxygen alarms can occur due to changes in barometric pressure (altitude) or extreme
changes in ambient temperature.
It is required that an oxygen calibration be performed at the room temperature. Be sure that the
detector is in known fresh air before performing a calibration.
