AB-6256
7
Maintenance
Periodic inspection
Since the measurement gases flow into the inside of the housing, annual cleaning of circuit boards inside the housing is
recommended.
Periodic calibration
The output drift (a maximum of 150 ppm/year) occurs even if this product is in continuously energized state. Be sure to conduct
a CO
2
zero gas calibration every year.
IMPORTANT:
As
mentioned
in
Installation
section, leaving the main unit non-energized for a long time may cause drift in
Table 1. In such a case, CO
2
zero gas calibration of the main unit must be carried out after the supply of power.
Note that the output needs about ten days to stabilize for the main unit continuously non-energized for a long
time. Please calibrate the main unit when it has been continuously energized for 10 days.
The zero calibration service bag (Part No. 83104511-001) needs to be ordered for the main unit calibration.
Refer to the following procedure and perform CO
2
zero gas calibration. (See Figs. 9 and 10)
1) Remove the front cover from the main unit.
2) Remove the adaptor attached to the rear side of the front cover, and attach the adaptor to the CO
2
zero gas inlet on the main
unit. Connect the zero calibration service bag with the main unit CO
2
zero gas inlet, referring to Specifications/Instructions
of the zero calibration service bag (AB-5803). Two inlets are provided on the main unit. Use either one.
3) Turn on the zero calibration service bag to start supplying CO
2
zero gas to the main unit.
4) Keep supplying the CO
2
zero gas until CO
2
concentration is stabilized (approximately for five minutes).
5) When
CO
2
concentration is stabilized, calibrate the main unit referring to Fig. 10.
6) Yellow LED lights up to indicate when calibration is completed successfully. Then, the LCD returns to display the CO
2
concentration.
7) Remove the adaptor from the CO
2
zero gas inlet and attach it to the rear side of the front cover.
8) Put the front cover back to the main unit.
Refer to AB-5803 for handling the zero calibration service bag (Part No. 83104511-001).
Layout of CO
2
zero gas inlets, buttons, and LED
Operation flow of CO
2
zero gas calibration and error code check
CO
2
zero gas inlets
(Use either one for CO
2
zero gas calibration.)
+ button
- button
Menu button
Yellow LED
Green LED
Figure 9. Layout of CO
2
zero gas inlets, buttons, and LED
on the main unit (without the front cover)
(Menu)
(Menu)
(-)
(Menu)
CO
2
concentration display [XXXX ppm]
Error code [EXXX]
Error code reset
Zero gas calibration [CAL]
Confirmation of zero gas
calibration excecution [SURE]
Execution of
zero gas calibration
(+)
(-)
(+)
(+)
(Menu)
(-)
(Menu)
(-)
(Menu): Press Menu button.
(+): Press + button.
(-): Press - button.
Notes:
∗
Indication on LCD returns to CO
2
concentration if no button is
pressed for 10 seconds.
∗
Let go of the main unit when LED turns on.
∗
Wait until the LED turns off, then go to the next operation.
[ ]: Indication on the LCD.
: CO
2
zero gas calibration
Figure 10. Operation flow of
CO
2
zero gas calibration and error code check.
