2.8 Monitoring Oxygen Concentration

The instrument monitors oxygen concentration in ambient air. The alarm setpoints can be set to activate on two different conditions:

• Enriched - oxygen concentration > 20.8 % or
• Deficient - oxygen concentration < 19.5 %.

While the instrument 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 instrument, leave the area immediately.
Remaining in the area under such circumstances can cause serious personal injury or death.

When the alarm setpoint is reached for either of the above conditions:

• an alarm sounds
• alarm LEDs flash
• a vibrating alarm triggers
• instrument displays and flashes the Alarm icon and either the Minimum icon (Enriched alarm) or the Maximum icon (Deficient alarm) along with the corresponding oxygen concentration.

The LOW alarm (oxygen deficient) is latching and will not automatically reset when the O2 concentration rises above the LOW setpoint. To reset the alarm, press the ▲ button. 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 pressure of use. Be sure that the instrument is in known fresh air before performing a calibration.