S+S Regeltechnik AERASGARD ALQ-CO2 Notice D'instruction page 7

G
Mounting and Installation
Automatic calibration of air quality (default)
The minimum initial value for air quality is memorized within a period of ca.
4 weeks. After that period has lapsed, the output signal is standardised to
zero-point (1.0 V). The maximum amount of correction is thereby limited to
1 V ⁄ interval. In this way, long-term drifts and operational aging effects of the
sensor element are completely eliminated.
Manual calibration of air quality
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 2 hours of continuous operation of the device at "normal" air quality
is to be ensured. Manual calibration of the output signal to 1 V (zero-point)
is started by pressing the button "Manual calibration" (for ca. 5 seconds).
Preparing for calibration is indicated by a blinking LED. Setting the output
to 1 V at actual ambient conditions follows automatically thereafter. During
this phase, the LED is permanently activated. After calibration is completed,
the LED is deactivated.
General information of air quality
Due to its functional principle, the lifetime of the sensor depends on nature and
concentration of the pollutant gas burden. The sensitive layer of the sensor ele-
ment reacts with all volatile organic compounds and is thereby modified in its
electrical properties or "exhausted". This process results in a displacement of
the characteristic curve. Such characteristic curve displacement however
amounts to less than 15 % ⁄ year under normal burden. In measuring air quality, the general condition of air quality is detected. Whether air quality is "good"
or "bad" is differently interpreted by each person. Different pollution burdens and concentrations influence the air quality signal (0 ...10 V) in different ways.
Examples for this are cigarette smoke, deodorant sprays, cleaning agents, or also various adhesive materials for floor and wall coverings as well as dyestuffs.
Increased burdens e.g. by solvents, nicotine, hydrocarbons, aerosol propellants etc. intensify consumption ⁄ aging of the sensor element. Particularly under
high pollutant gas burdens – also during non-operational idle state periods of the devices (transport and storage) – zero-point drift will occur. Consequently,
this must be corrected at site according to the respective circumstances or basic burdens. Air quality measuring instruments of different manufacturers
cannot directly be compared because of different functional principles, preset basic burdens (zero-point), and permitted burdens (amplification ⁄ sensitivity).
Devices are preset respectively calibrated according to the sensor manufacturer's specifications. Here, a zero-point and a final value is determined and thus
a maximum burden. In particular cases, exceeding measuring ranges or excessive basic burdens on the devices will occur (outgassing floor carpeting, wall
paint, etc.). In order to enable distinguishing different air qualities, devices need to be adjusted by the customer according to the conditions existing on site
that do not correlate to the factory-preset definition range and calibration. Please note that factory calibration is thereby lost and compliance with technical
data can no longer be guaranteed.
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
at least for 10 minutes during each 7- day period. For self-calibration, the devices memorises device-internally the CO
during a 7- day period. After 7 days, this minimum value is standardised to 350 ppm CO
of correction is here limited to 100 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
signal to 1.75 V (350 ppm = zero-point) is started by pressing the button "Manual calibration CO
by a blinking LED. Setting the output to 1.75 V at actual ambient conditions follows automatically thereafter. During this phase, the LED is permanently
activated. After calibration is completed, the LED is deactivated. Air quality is measured by a chemical sensor.
Type ⁄ WG1 Measuring Range
VOC
ALQ - CO
2
A L Q - C O 2 0 ...100 %
A L Q - C O 2 _ DIS P L AY 0 ...100 %
A L Q - C O 2 W 0 ...100 %
A L Q - C O 2 W_ DIS P L AY 0 ...100 %
ATM = Sensor for atmospheric pressure compensation included
Note: This unit must not be used as safety-relevant device!
CO
2
(switchable)
0...2000 ⁄ 5000 ⁄ 10000 ppm
0...2000 ⁄ 5000 ⁄ 10000 ppm
0...2000 ⁄ 5000 ⁄ 10000 ppm
0...2000 ⁄ 5000 ⁄ 10000 ppm
VOC
(sensitivity adjustable)
VOC LOW
VOC MEDIUM (default)
VOC HIGH
VOC - Calibration mode
adjustable
Automatic self-calibration
Manual calibration
CO content
2
(measuring range selectable)
0 ... 2000 ppm (default)
0 ... 5000 ppm
0 ... 10000 ppm
CO calibration mode
2
(adjustable)
Automatic self-calibration
Manual calibration
and the output signal is corrected accordingly. The maximum amount
2
content 300 ... 400 ppm) is to be ensured. Manual calibration of the output
2
" (for ca. 5 seconds). Preparing for calibration is indicated
2
Output Features
(2x)
0 - 10 V ATM
0 - 10 V ATM
0 - 10 V ATM, Changeover contact
0 - 10 V ATM, Changeover contact
DIP DIP
1 2
O N OFF
O N
OFF
OFF OFF
DIP DIP
1 2
O N OFF
O N
OFF
OFF OFF
content 300 ... 400 ppm)
2
content minimum value measured
2
Display Item No.
1501- 1111- 1000-022
■ 1501- 1111- 1010-000
1501- 1111-1300-022
■ 1501- 1111- 1310-022
DIP
3
OFF
OFF
O N
DIP
4
OFF
O N
DIP
3
OFF
OFF
O N
DIP
4
O N
OFF