S+S Regeltechnik AERASGARD ACO2, Operating Instructions, Mounting & Installation

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G
Mounting and Installation
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 pres-
sure 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. Depend-
ing on changes in the CO
2
concentration and flow velocity of the air sur-
rounding the sensor, the reaction of the device to changes in CO
2
con-
centration 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.
Automatic calibration of carbon dioxide measurement (default)
The device calibrates itself at an interval of 7 days. To ensure this
function, the device needs to be supplied with fresh air (CO
2
content
300 ... 400 ppm) at least for 10 minutes during each 7-day period. For
self-calibration, the devices memorises device-internally the CO
2
con-
tent minimum value measured during a 7-day period. After 7 days, this
minimum value is standardised to 350 ppm CO
2
and the output signal is
corrected accordingly. The maximum amount of correction is here limit-
ed to 40 ppm ⁄ interval.
Manual calibration of carbon dioxide measurement
Manual calibration can be started independently from the position of
the DIP 4 switch by pushing the button (probe 2). After connecting
the device, a period of at least 10 minutes of continuous operation of
the device at fresh air (CO
2
content 300 ... 400 ppm) is to be ensured.
Manual calib ration of the output signal to 1.75 V (350 ppm = zero-point)
is started by pressing the button “Manual calibration CO
2
“ (for ca. 5
seconds). Preparing for calibration is indicated by a blinking LED. Setting
the output to 1.75 V at actual ambient conditions follows automatically
there after. During this phase, the LED is permanently activated. After
calibration is completed, the LED is deactivated.
Putting in operation
After switching on the device, a self-test and tempering period follows.
This procedure takes 3 to 5 minutes, depending on ambient conditions.
During this time, the output analog voltage differs from the actual meas-
ured value.
CO
2
content
(measuring range selectable)
DIP
1
DIP
2
DIP
3
0 … 2000 ppm (default)
O N
OFF OFF
0 … 5000 ppm OFF
O N
OFF
0 … 10000 ppm OFF OFF
O N
CO
2
calibration mode
(adjustable)
DIP
4
Automatic self-calibration O N
Manual calibration OFF
Type ⁄ WG1 Measuring Range
CO
2
Output
CO
2
Features Display Item No.
ACO
2
(switchable)
AC O2 0...2000 ⁄ 5000 ⁄ 10000 ppm 0 - 10 V ATM 1501-1110-1001-022
AC O2 _ DISP L AY 0...2000 ⁄ 5000 ⁄ 10000 ppm 0 - 10 V ATM ■ 1501-1110-1011-022
AC O2 W 0...2000 ⁄ 5000 ⁄ 10000 ppm 0 - 10 V ATM, Changeover contact 1501-1110-1300-022
AC O2 W_ DISP L AY 0...2000 ⁄ 5000 ⁄ 10000 ppm 0 - 10 V ATM, Changeover contact ■ 1501-1110-1310-022
ATM = Sensor for atmospheric pressure compensation included
Note: This unit must not be used as safety-relevant device!