Monitoring Toxic Gases

The device can monitor the concentration of the following toxic gases in ambient air:

• Carbon Monoxide (CO)
• Hydrogen Sulfide (H2S)
• Sulfur Dioxide (SO2)
• Nitrogen Dioxide (NO2)

The device displays the gas concentration in parts per million (PPM) or mg/m3 on the Normal Operations page until another page is selected or the device is turned off.

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.

 

The device has four gas alarms for each toxic gas:

• HIGH Alarm
• LOW Alarm
• STEL Alarm
• TWA Alarm

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.

In the event of a CO or H2S over-range exposure:

1. Return the instrument to a fresh air environment and allow the CO and H2S sensors to recover.
2. If the sensor fully recovers, it is recommended to perform a FAS prior to use.
3. If the sensor maintains a significant baseline drift, allow the instrument to recover for a full 24 hours in a clean air environment prior to performing a zero and span calibration.