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

Duct air quality and co2 sensor

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Operating instructions, mounting & installation (17 pages)

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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

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

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

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

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.

Type ⁄ WG1

Measuring Range

VOC

KLQ - CO

0 ...100 %

KLQ - CO

- W

0 ...100 %

xx - Display

Note:

This unit must not be used as safety-relevant device!