ENMET ISA-44-2OD - Manual (Page 23)

ISA-44-2-OD ENMET Corporation
19
5.2.3 Combustible Gas Channel # 3
1. Wait 8 - 10 minutes for the sensor to recover from the test.
2. Repeat steps 3 - 7 as outlined in the test procedure above using the high level calibration gas.
3. With the gas still flowing, adjust the Meter Adjust potentiometer (Ref. Figure 4) R33; ccw to increase, cw to
decrease meter reading) with a small screwdriver.
• You want to have the meter pass through the low level alarm point, to verify that the alarm light triggers.
• If it does not, set the meter to the low alarm point and adjust R35 ( low level alarm POT ).
• Then adjust the meter gain POT to pass through the high alarm point, verify that the alarm light triggers at the
high alarm point.
• If it does not, set the meter gain to the high alarm point adjust R34 to trigger the alarm light.
• Turn the switch to OPERATE for a second to verify the horn is operational. This sets the alarm points.
C AUTION : D O N OT adjust for instantaneous alarm when test gas is first released. If you do, the calibration is inaccurate,
and the sensor is overly sensitive.
4. Shut off the calibration gas flow at the valve on the gas cylinder.
5. Remove the calibration gas, the flow of clean air should clear the unit from its gas alarm state in less than one
minute. After the alarms have cleared, turn the switch to OPERATE .
C AUTION : Do not use calibration gas with inert gases such as argon or nitrogen as a background. The background gas
must be "air" or equivalent.
C AUTION : Do not totally dry gases directly from high-pressure cylinders.