General Monitors 4802A Instruction Manual page 42

3. When the Mode/Select switch is released, the display will indicate a flashing pair of
bars (- -) for about ten seconds.
4. When the display indicates a flashing 0, apply the test gas to the sensor (open the
valve on the cylinder and the ON/OFF valve) and wait for a few seconds. The
display will begin to go up scale as the sensor sees the gas. If the display does not
change after 6 minutes, the unit will return to the normal operating mode.
5. If the sensor does see the gas, the read-out on the display will be flashing for as
long as the unit remains in the Calibration Check mode.
6. The reading will stabilize after 30 to 60 seconds of exposure to the test gas. This
response time may increase due to the presence of the TGA-1, RC-3, Dust Guard,
Splash-Guard or other sensor accessories.
7. The operator should compare the reading with the gas concentration applied and
determine if it is necessary to calibrate the sensor.
8. The A1 & A2 alarms are disabled during the Calibration Check Mode. Use the
Setup Check Mode to verify the alarm set points for A1 and A2.
9. If the reading is acceptable remove the gas and allow the sensor to see clean air.
10. If the operator determines that a calibration is necessary, do one of the following:
• If the applied gas concentration is equivalent to the user specified calibration
level, place the unit in the calibration mode by pressing the Mode/Select switch,
or
• If the applied gas concentration is not equivalent to the user specified calibration
level, remove the gas, allowing the sensor to see clean air, then follow the
calibration procedure listed in Section 5.3 of this chapter.
NOTE - If the 3-Liter Calibration Chamber is used with vapors or fumes from a volatile
liquid/solvent, use the procedures listed in Section 6.8.
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Model 4802A