MSA altair 4 - Sensor Missing Alarm; Monitoring Toxic Gases

MSA DESCRIPTION
ALTAIR 4 - Operating Manual 19
2.4 Sensor Missing Alarm
The instrument enters the Sensor Missing alarm if the instrument detects
that an enabled sensor is not properly installed in the instrument or is not
functional.
For O
2
, CO, and H
2
S sensors, the Sensor Missing feature is checked when
the instrument is turned ON and when leaving the Setup mode.
The combustible Sensor Missing feature is continuously monitored.
If a sensor is detected as missing, the following occurs:
• "SENSOR ERROR" displays
• The flag above the sensor detected as missing flashes on the display
• Alarm sounds and lights flash.
• If there is a sensor error at startup, the instrument shuts OFF in
60 seconds.
2.5 Monitoring Toxic Gases
The instrument can monitor the concentration of the following toxic gases in
ambient air:
• Carbon Monoxide (CO)
• Hydrogen Sulfide (H
2
S)
The instrument displays the gas concentration in parts per million (PPM) or
mg/m
3
on the Measuring page until another page is selected or the
instrument is turned OFF.
WARNING
If an alarm is triggered while using the instrument, leave the area
immediately.
Remaining on site under such circumstances can cause serious personal
injury or death.
The instrument has four gas alarms:
• HIGH Alarm
• LOW Alarm
• STEL Alarm
• TWA Alarm
If the gas concentration reaches or exceeds the alarm set point, the instrument:
• backlight turns on
• a vibrating alarm triggers
• displays and flashes the Alarm icon and either the Minimum
icon
(LOW alarm) or the Maximum icon (HIGH alarm)
• enters an alarm state.