Alarm Indications - Crowcon Gasman User Manual

Gasman
IV. Alarm indications
Gasman provides two instantaneous alarm levels, designated level 1 and
level 2. For toxic gas sensors, there are also two time weighted average
alarms (TWA), one for short term exposure (STEL): based on a 15 minute
time weighted average, and the second TWA alarm is for long term expo-
sure: based on a 8 hour time weighted average.
Alarm configurations are set via the Crowcon Portables PC software.
The following settings can be made:
Alarm thresholds for each sensor: Level 1 and
level 2 alarms can be set for the gas sensor.
Alarm trigger: This can be set to rising levels of gas
concentration, or as falling. Oxygen units are set to falling for defi-
ciency monitoring.
Alarm latching: Alarms can be set to be latched or unlatched.
Latched alarms will require the operator button to be pressed in
order to clear the alarm. This is the default setting. Unlatched
alarms will clear automatically when the gas hazard has passed.
Alarm mute: The sounder can be set to mute for level 1 alarm
only; pressing the operator button during an alarm condition i.e.
presence of hazardous gas, will silence the sounder and stop the
vibration alarm. The alarm LEDs will continue to flash.
Alarm sounder tone: Different distinctive tones can be selected
for the each alarm condition to achieve the best performance for
the monitoring conditions available.
In the event of a Time Weighted Alarm (TWA)
In the event the 15 minute or the 8 hour TWA is triggered,
Gasman will go into alarm and display a TWA warning with
the toxic gas readings. The 8 hour TWA alarm cannot be
cleared.
Alarm indications