CP01 Fixed gas detector operation manual
6
6. Calibration
After using for some time, the accuracy of the sensor will be influenced due to
the sensor shift. The sensor should be calibrated by professional person
according to the following steps:
6.1 4-20mA detector calibration
a) Zero calibration:
Put the detector into the clean air at least 10 minutes, press S2 and S3 together
about 1-2 seconds. At the moment, the Green light will flash from keeping on.
The detector can be calibrated now. Put the first switch of S1 on the place of
“ON”, and then red LED begins to flicker for about 10minutes. During this
time, inject Nitrogen or synthetic air into the sensor by 0.5L/min flow. And
then put the first switch of S1 on the place of “OFF”. Then the Red light will
flash several times and be off. Zero calibration will be ok.
b) Alarm level calibration:
Prepare one bottle of span gas. Generally it’s half of the whole range(e.g.
Methane is 50%LEL) or other span gas;
Prepare Gas flow meter;
Press S2 and S3 together for 1-2 seconds. The green light will be from
keeping on to flash. The detector enters calibration status. Switch the
third digit to “on”. (i.e. 50%F.S.) The red light will flash. The
corresponding calibration point is as the following table.
Note: The black block means the switch location
Connect the calibration gas and flow meter by pipe correctly. Turn on the
calibration gas and adjust the gas flow meter. Connect the pipe with detectors
calibration cap. Then the calibration gas will diffuse into the sensor. After
about 2minutes, the display of controller will be the same as the calibration
point. Then turn the switch to “off”. The detector remembers the value. The
red light will flash several times and then be off.
Turn off the calibration gas and take off the pipe. The calibration will be
finished.
