Datasheet

G
Installation and Commissioning Rev. 2019 - V32
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 – ABC logic (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 at
times 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 ABC logic requires continuous operating cycles of longer than
24 hours in order to function properly.
Manual calibration of carbon dioxide measurement
Manual calibration can be carried out independently of the DIP switch position (ABC logic).
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.
Afterwards, it is mandatory to run the manual calibration procedure. Thereafter the ABC logic may be activated.
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.
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 50 % – – – –
– 500 75 % – – – –
350 750 100 % – – – –
400 1000 25 % – – –
500 1250 50 % – – –
600 1500 75 % – – –
700 1750 100 % – – –
800 2000 25 % – –
900 2250 50 % – –
1000 2500 75 % – –
1100 2750 100 % – –
1200 3000 25 % –
1300 3250 50 % –
1400 3500 75 % –
1500 3750 100 % –
1600 4000 25 %
1700 4250 50 %
1800 4500 75 %
1900 4750 100 %
2000 5000
Once the aforementioned values have been reached, the respective LED becomes active
(with increasing luminosity of 25 %, 50 %, 75 % and 100 %); LEDs that are already active
continue to be illuminated.
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!