G
Installation and Commissioning
Rev. 2020 - V34
ATTENTION !
The minimum CO
2
concentration of outside air in leafy, hardly industrialised areas is approx. 350
ppm (output voltage = 1.75
V
with MR = 0...2000 ppm
or 0.7 V with MR = 0...5000 ppm). The
gas inter-exchange in the sensor element happens by diffusion.
Depending on the changes to the concentration
and the flow velocity of the air surrounding the sensor, the reaction of the device to the change of concentration may take place with a delay.
It is essential to choose an installation location for the device in which the air stream flows around the sensor. Otherwise the gas exchange may
be considerably delayed or prevented.
Automatic calibration of the carbon dioxide measurement – (default)
The automatic background logic is a self-calibrating mechanism that is suitable for use in applications in which the CO
2
concentration regularly drops to
fresh air level (350 - 400 ppm). This should typically happen attimes during which the rooms are unoccupied. The sensor reaches its normal accuracy
after 24 hours of continuous operation in an environment which has been exposed to a fresh air supply of 400 ppm CO
2
. The deviation error remains
minimal with at least 4 cases of sensor exposure to fresh air within 21 days. The device needs continuous operating cycles of more than 24 hours
to operate correctly
Manual calibration of carbon dioxide measurement
Manual calibration can be carried out independently of the DIP switch position.
Sufficient fresh air (CO
2
content = 500 ppm) must be provided before and after the calibration procedure!
The calibration procedure is started by pressing the "ZERO" button (for approx. five seconds).
This is signalled via the flashing LED.
Then calibration takes place. During this phase, the LED is continuously active and a 600 second countdown runs.
The LED is deactivated after successful calibration.
Putting in operation
After switching on the device, a self-test and tempering period follows. This procedure takes 30 - 50 minutes depending on ambient conditions.
Manual calibration can then be performed as an option. Make sure that no harmful substances influence the calibration process and that the
sensor is operated in fresh air.
Switching point setting
A potential-free changeover contact is available as a switch output.
A switching point between 10 % and 95 % of the measuring range can be selected using the SET potentiometer.
The 10 % value is added to the fresh air limit of 400 ppm for CO
2
.
(600...1900 ppm with MR = 0...2000 ppm or 900...4700 ppm with MR = 0...5000 ppm).
Offset
Each measuring channel has a separate offset potentiometer for subsequent adjustment of the measurement.
The adjusting range is ± 10 % of the measuring range.
DIP switches
RCO
2
- W
CO
2
content
DIP 1
0...2000 ppm (default)
OFF
0...5000 ppm
O N
CO
2
automatic zero point
DIP 3
deactivated
OFF
activated (default)
O N
Output
DIP 4
Voltage 0 -10 V (default)
OFF
Current 4...20 mA
O N
Traffic light (5x LEDs)
DIP 5
deactivated
OFF
activated
O N
Note:
DIP 2
is not assigned!
Traffic light indicator
RCO
2
- W - A
CO
2
content in ppm
0...2000 ppm
0...5000 ppm
LED 1
green
LED 2
green
LED 3
yellow
LED 4
yellow
LED 5
red
350
350
20 %
–
–
–
–
416
536
40 %
–
–
–
–
482
722
60 %
–
–
–
–
548
908
80 %
–
–
–
–
614
1094
100 %
–
–
–
–
680
1280
20 %
–
–
–
746
1466
40 %
–
–
–
812
1652
60 %
–
–
–
878
1838
80 %
–
–
–
944
2024
100 %
–
–
–
1010
2210
20 %
–
–
1076
2396
40 %
–
–
1142
2582
60 %
–
–
1208
2768
80 %
–
–
1274
2954
100 %
–
–
1340
3140
20 %
–
1406
3326
40 %
–
1472
3512
60 %
–
1538
3698
80 %
–
1604
3884
100 %
–
1670
4070
20 %
1736
4256
40 %
1802
4442
60 %
1868
4628
80 %
1934
4814
100 %
2000
5000
Once the aforementioned values have been reached, the respective LED becomes active
(with increasing luminosity of 20 %, 40 %, 60 %, 80 % and 100 %);
LEDs that are already active continue to be illuminated.
