26 • Operation
GX-2009 Operator’s Manual
CAUTION:
Any rapid increase in the combustible gas reading followed by a declining or
erratic reading may indicate a gas concentration above the LEL which may be
hazardous.
•
Some gases such as silicone vapors, chlorinated hydrocarbons, and sulphur compounds
can contaminate the detection elements inside the combustible sensor damaging the sensor
and resulting in reduced response to combustible gas. Make every effort to avoid these
gases. The H
2
S scrubber disks protect the combustible sensor from H
2
S, but you should
avoid other sulphur compounds.
Alarms
This section covers alarm indications. It also describes the two types of alarm logic, how to
reset the GX-2009 after an alarm has occurred, and how to respond to an alarm condition.
NOTE:
False alarms may be caused by radio frequency (RF) or electromagnetic (EMI)
interference. Keep the GX-2009 away from RF and EMI sources such as radio
transmitters or large motors.
Alarm Indications
The GX-2009 will sound an alarm, the LEDs will flash, and the unit will vibrate when one of
the target gas concentrations rises above the Warning (low alarm) setpoint, or in the case of
oxygen falls below the Warning setpoint, for that gas.
The GX-2009 will also sound an alarm, the LEDs will flash, and the unit will vibrate when the
Alarm (high alarm) setpoint is reached for any of the channels and when the STEL and TWA
alarm points are reached for CO and H
2
S.
When a trouble condition occurs, such as a sensor failure or low battery charge, the alarm
indication will depend on the alarm type.
Table 4 below summarizes the types of alarms produced by the GX-2009.
Table 4: Alarm Types and Indications
Alarm Type
Visual Indications
Other Indications
Warning (low alarm)
Concentration of gas rises above the
Warning setpoint or falls below the
Warning setpoint for O
2
•
WARNING
blinks to the right
of the battery level icon
• Reading for the gas in alarm
flashes
• Alarm LEDs flash
• Backlight turns on
• Buzzer sounds alternating
between a low and high
pitch
• Vibrator pulses
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