June 12, 2012
Page 6 out of 14
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When you keep touching it more than 5 seconds, the setting value decrease very
fast.
ENT
Restore the set value
POW
Power on.
AL1
AL1 operates.
AL2
AL2 operates.
RX
RS-485 receives signal.
TX
RS-485 sends signal.
[Sensor Calibration]
Gas sensor’s property is subject to change while it is being used. This is common to all sensors. You
have to calibrate the sensor periodically to keep the optimum condition of sensor.
DA-50 has automatic calibration function by micro processor.
1. Zero calibration
Please follow below process to zero-calibrate sensor output.
①
Please keep touching the MODE key more than 2 seconds through glass window and enter
into setting mode.
②
Then, LCD shows “CAL-[ZERO]”. Please touch ENT key.
③
Then, LCD shows “ZERO GAS”. Please infuse the standard gas.
④
When the measured value gets stable, please touch ENT key.
⑤
Then, if zero calibration is successful, LCD shows “[OK]”.
▲ Caution:
For zero calibration, you should have clean status without any gases. If you cannot have
clean status, please use nitrogen gas for zero calibration.
2. Span calibration
Please follow below process using standard gas to calibrate the linear change of sensor output.
①
Please assemble calibration nipple on sensor cap.
②
Then, please touch MODE key more than 2 seconds after disassembling main cover. It leads
you to setting mode.
③
Then, please move to “CAL [SPAN]” menu and touch ENT key.
④
Then, LCD shows “SPAN-ADJ”. Please input desired calibration gas density values touching
UP & DOWN keys. When you finish it, please touch ENT key. (gas density set finished)
⑤
Then, LCD shows “SPAN-GAS”. Then, please infuse the calibration standard gas. While you
infuse the gas, LCD values approaches the values of gas density. When the LCD shows stable
gas values, please touch ENT key. (span calibration finished).
