G
Mounting and Installation
Switching thresholds
RTM - CO
2
- 2S
Potentiometers
ATTENTION!
The minimum CO
2
concentration of outdoor air amounts to ca. 350 ppm (output
voltage = 1.75 V) in leafy, hardly industrialized areas. A sensor self-test is initiated
by above-atmospheric or below-atmospheric pressure or by exposure of the sensor
to more than 5000 ppm CO
2
. The output voltage (CO
2
output) amounts to ca.
0.2 Volt during the self-test. Gas inter-exchange in the sensor element happens by
diffusion. Depending on changes in the CO
2
concentration and flow velocity of the air
surrounding the sensor, the reaction of the device to changes in CO
2
concentration
may appear with a delay. It is absolutely necessary to choose the device mounting
position so that the air stream “presses” into the duct tube. Otherwise, below-
atmospheric pressure will develop in the duct tube that may cause a substantial
slow down of gas exchange or even prevent it.
Putting in operation
After switching on the device, a self-test and tempering period follows. This proce-
dure takes 3 to 5 minutes, depending on ambient conditions. During this time, the
output analog voltage differs from the actual measured value.
Traffic light indication
RTM - CO
2
- A
LED
CO
2
content
Green 1
0 - 500 ppm
Green 2
500 - 800 ppm
Yellow
800 - 1200 ppm
Red 1
1200 - 1600 ppm
Red 2
> 1600 ... > 2000 ppm
Traffic light indication
RTM - CO
2
- 2S
LED
CO
2
content
Green
< 800 ppm
Yellow
800 - 1200 ppm
Red
> 2000 ppm
Type ⁄ WG1
Measuring Range
Output
Features
CO
2
Temperature Humidity
RFTF - CO
2
0 … 2000 ppm
+5 ...+ 40 °C
30 ...80 % r. H.
3 x 0 -10 V
–
RTM - CO
2
0 … 2000 ppm
0 ...+ 50 °C
–
2 x 0 -10 V
–
RTM - CO
2
- Stainless steel enclosure
Stainless steel enclosure
RTM - CO
2
- A
0 … 2000 ppm
0 ...+ 50 °C
–
2 x 0 -10 V
5-LED - indicator (traffic light)
RTM - CO
2
- 2S
0 … 2000 ppm
+5 ...+ 40 °C
–
2 x 0 -10 V
3-LED - indicator (traffic light),
2 x NO contact
“Traffic light” (coloured LEDs) indicating air quality (CO
2
).
Note:
This unit must not be used as safety-relevant device!
Measuring range CO
2
RTM - CO
2
- 2S
(adjustable)
Switching thresholds
S1
S2
Lower limit
Upper limit
1
0 ppm
1200 ppm
2
200 ppm
1400 ppm
3 400 ppm
1600 ppm
4 600 ppm
1800 ppm
5 800 ppm
2000 ppm
S1
S2
5
3
4
2 1
5
3
4
2 1
