MSA ALTAIR Pro H2S Manual De Operación página 19

• High Alarm
• Low Alarm
• STEL Alarm
• TWA Alarm
• The backlight turns ON for 20 seconds during an alarm condition.
1. If the gas concentration reaches or exceeds the low alarm setpoint:
• The instrument will:
• display and flash "LO" and "ALARM" on the LCD
• enter a low alarm sequence.
• The low alarm can be silenced for five seconds by pressing the
TEST button; it automatically clears once the gas level falls
below the setpoint.
2. If the gas concentration reaches or exceeds the
high alarm setpoint:
• The instrument will:
• display and flash "HI" and "ALARM" on the LCD
• enter a High alarm sequence.
• The high alarm can be silenced for five seconds by pressing
the TEST button while it is still in high alarm.
• The High alarm is latching and will not reset when gas
concentration falls below the HIGH setpoint.
NOTE: To reset alarm, push the TEST button after the gas
• Refer to the instrument during turn ON for factory-set alarm points.
• If a gas concentration exceeds an alarm setpoint, the:
• Audible alarm sounds
• Alarm lights flash
• Vibrator activates
• Alarm type displays, alternately flashing the ALARM icon
and the:
• LO icon (if the low alarm setpoint was exceeded)
• HI icon (if the high alarm setpoint was exceeded).
3. If the STEL (Short Term Exposure Limit) reading reaches or
exceeds the STEL alarm setpoint:
• The instrument will:
• display and flash "LO" AND "ALARM" on the LCD
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level falls below the setpoint.