Rae Q-RAE, Operation And Maintenance Manual

Page: 32 / 170

OPERATION
2 - 18
2.5 Alarm Signals
The built-in microcomputer constantly updates and
monitors gas concentration and compares it with the
programmed alarm limits (TWA, STEL, and two
instantaneous gas concentration alarm limit settings: Low
& High). Whenever the concentration exceeds any of the
preset limits, the loud buzzer and red flashing LED are
activated immediately to warn the user of the alarm
condition.
In addition, the Q-RAE will alarm if one of the following
condition occurs: battery voltage falls below a pre-set
voltage level (4.4 V), LEL sensor off, pump stall or when
the datalog memory is full. When the low battery alarm
occurs, there will be approximately 20-30 minutes of
operating time remaining. When the battery voltage falls
below 4.2 V, the monitor will be turned off automatically.
Alarm Signal Disabled: It is extremely important
to note that during the following conditions, the
alarm signals are disabled:
1) In PC communication standby mode.
2) In calibration mode (including reviewing
datalog data).
During these modes of operation, real time monitoring of
the gas concentration stops. None of the gas concentrations
will be calculated, including Peak, STEL and TWA.