S+S Regeltechnik AERASGARD KLQ-CO2 Operating Instructions, Mounting & Installation Download Page 7

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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  jumper  J2
by  pushing  the  button.  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  acti-
vated. 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
element 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

content 300 ppm ...

400 ppm) at least for 10 minutes during each 7- day period. For self-calibration, the devices memorises device-internally the CO

content minimum

value measured during a 7- day period. After 7 days, this minimum value is standardised to 350 ppm CO

and the output signal is corrected accord-

ingly. The maximum amount of correction is here limited to 40 ppm ⁄ interval.

Manual calibration of carbon dioxide measurement
Manual calibration can be started independently from the position of jumper J3 by pushing the button. After connecting the device, a period of at
least 10 minutes of continuous operation of the device at fresh air (CO2 content 300 ppm...400 ppm) is to be ensured. Manual calibration of the
output signal to 1.75 V (350 ppm = zero-point) is started by pressing the button “Manual calibration CO

“ (for ca. 5 seconds). Preparing for calibra-

tion is indicated 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.

VOC
(sensitivity adjustable)

VOC LOW

VOC MEDIUM (default)

VOC HIGH

content

(measuring range adjustable)

0 … 2000 ppm (default)

0 … 5000 ppm

0 … 10000 ppm

Type ⁄ WG1

Measuring Range

Output