Maintenance – ROTRONIC CF8-W-Disp-GH User Manual
Page 6

Dokument
UMA 146
Rev
1
Page
6 (7)
Maintenance
The CF8-W-Disp-GH is basically maintenance free. An internal self-adjusting
calibration function takes care of normal long term drift associated to the CO
2
sensor.
To secure the highest accuracy, a time interval of five years is recommended
between CO
2
calibrations, unless some special situations have occurred. A zero
calibration can be performed by use of pure nitrogen or air that has passed through a
chemical absorber and a PC together with the UIP software version 4.3 (or higher).
The Service bag can be used to produce carbon dioxide free air. The software can
be free downloaded from www.rotronic.com. The RS232-cable and the service bag
can be ordered from Rotronic. The cable is to be connected to the UART port slide
connector (see Fig. 5). For change of control parameters and re-calibration (CO
2
and
temperature) this PC tool has to be used. The check can be done on site without
interfering with the ventilation system.
When a zero calibration shall be executed a plastic tube with 2,2 mm outer diameter
and 0,8 mm inner diameter shall be inserted in marked holes of the sensor. A plastic
tubing is connected to the tube. The gas flow should be between 0,3 and 1,0 l/min.
Figure 5. Part of the PCB with holes for gas inlets marked.
Gas inlet
Gas inlet