Monitoring Oxygen Concentration - MSA ALTAIR 4XR Operating Manual

If the gas concentration reaches or exceeds the alarm set point, the device:
• backlight turns on
• triggers a vibrating alarm
• displays and flashes the Alarm symbol and either the Minimum icon (LOW alarm) or the Maximum
(PEAK) icon (HIGH alarm)
• enters an alarm state.
When a gas reading exceeds the full scale range of the sensor, the device displays "+ +
+" in place of the actual reading.
When a gas reading falls below a defined under-range threshold, the device displays " -
- -" in place of the actual reading.
2.10

Monitoring Oxygen Concentration

The device monitors the oxygen concentration in ambient air. The alarm set points can be set to acti-
vate on two different conditions:
• Enriched - oxygen concentration > 20.8% or
• Deficient - oxygen concentration < 19.5%.
While the device can detect up to 30% oxygen in the ambient air, it is approved for use only up to 21%
oxygen-content.
WARNING!
If an alarm activates while using the device, leave the area immediately.
Remaining in the area under such circumstances can cause serious personal injury or death.
When the alarm set point is reached for either of the above conditions:
• an alarm sounds
• alarm LEDs flash
• a vibrating alarm triggers
• device displays and flashes the Alarm icon and either the Minimum icon (Enriched alarm) or the
Maximum icon (Deficient alarm) ( chapter 2.3 "On-Screen Indicators") along with the corre-
sponding oxygen concentration.
The LOW alarm (oxygen deficient) is latching and will not automatically reset when the
concentration rises above the LOW set point. To reset the alarm press the  button.
O
2
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 recommended that an oxygen calibration be performed at the temperature and pres-
sure of use. Be sure that the device is in known fresh air before performing a calibration.
When a gas reading exceeds the full scale range of the sensor, the device displays "+ +
+" in place of the actual reading.
When a gas reading falls below a defined under-range threshold, the device displays " -
- -" in place of the actual reading.
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ALTAIR 4XR
Description
US
19