MultiRAE
User’s Guide
67
If gas or radiation alarm conditions exist (High, Low, Max, Over, STEL, or TWA alarms), the operation
pattern switches to a much shorter, one-
second
-long cycle
in which gas measurements are taken for 0.7
seconds followed by gamma radiation measurements that are taken during the remaining 0.3 seconds.
Like under non-alarm conditions, the pump stays on when gas measurements are taken, but it is turned off
when gamma radiation is measured.
MultiRAE Pro Operation in Multi-Threat Mode in Alarm Conditions
Once alarm conditions subside, the operation pattern returns to the “55 sec. gas / 5 sec. radiation” cycle.
Note:
Because of the MultiRAE Pro’s intermittent pump operation in multi-threat mode, during the part
of the cycle in which the pump is turned off, the PID sensor lamp is automatically cleaned by ozone that
forms above the PID lamp crystal (this ozone is removed by the air flow when the pump is running.) This
auto-clean feature reduces PID sensor maintenance frequency.
11.2 Gamma Radiation-Only Measurement Mode
When the instrument is in gamma-only mode, gas sensors are not shown on the display and gas
measurements are not taken. The pump remains off and gamma radiation is measured all the time in all
cases, as illustrated below:
MultiRAE Pro Operation in Gamma-Only Mode
WARNING
Toxic and combustible gases cannot be detected by the MultiRAE when it is operated in gamma-
only mode.
Activating Gamma-Only Measurement Mode
To activate gamma-only measurement mode:
1.
Press [N/-] when the instrument is running in normal (multi-threat) mode:
Summary of Contents for MultiRAE
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