11
G
AERASGARD
®
FSFTM - CO2 - Modbus
Rev. 2021 - V12
ATTENTION!
The minimum CO2
concentration of outdoor air amounts to approx. 350 ppm (output voltage = 1.75 V
at MR = 0...2000 ppm or 0.7 V at
MR = 0...5000 ppm) in leafy, hardly industrialised areas. 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.
Commissioning
After the device is switched on, a self-test and temperature equalisation are performed. Depending on the ambient conditions, this process takes
30-50 minutes (
as an option,
manual calibration
can now be performed). If commissioning with
automatic calibration
, proceed as follows:
1.
Open all windows or set the air conditioning system to use outdoor air
2.
Switch on the device and move away from the device. If possible, all persons should leave the room.
3.
The device is ready to use after 50 minutes. .
Automatic calibration of the CO2 measurement – ABC logic
The regular exchange of fresh air is all that is required for the self-calibration technology in the sensor (CO2 concentrations: 350-500 ppm). The
device detects this condition and performs the calibration automatically. It is sufficient to open the windows or set the air conditioning system to use
outdoor air at regular intervals and to stop all CO2-producing processes that influence the ambient air. Proceed as follows:
Open all windows fully or set the air conditioning system to use outdoor air 1x weekly for 15-20 minutes.
If possible, all persons should leave the room during this time.
Regular ventilation of the rooms and flushing of the duct with fresh air will increase the measuring accuracy of the sensor.
Automatic calibration
is deactivated by default in the as-delivered condition and, if required, must be activated using the Modbus.
Manual calibration of CO2 measurement
Manual calibration can be carried out irrespective of the ABC logic. Sufficient fresh air must be provided before and during the calibration procedure
(CO2 concentration: 350-500 ppm). Also make sure that no CO2-producing processes influence the ambient air. Proceed as follows to perform
manual calibration:
1.
Preparation: Remove the housing cover and open all windows or set the air conditioning system to use outdoor air.
2.
Press and hold the “
ZERO CO2
” button until the flashing LED row changes to a steady light after 5 seconds.
Devices with a display indicate “
AUTO 0
” and change the countdown from 5 to 600.
The calibration process has started. Keep the windows open or the air conditioning system set to use outdoor air.
3.
If possible, all persons should now leave the room.
4.
After 10 minutes, the calibration is complete (status LED has gone out, the countdown is complete) and the device should indicate or transmit
a CO2 concentration of between 350-500 ppm.
5
5
6
7
6
7
4
3
4
3
free
free
Shielding
Modbus A
Modbus B
UB–
GND
UB+
24V
AC/DC
Connecting diagram
FSFTM - CO2 - Modbus
address
Top
1 2 3 4 5 6 7 8
ON
mode
1 2 3 4 5 6
ON
ZERO
Schematic diagram
FSFTM - CO2 - Modbus
