G
Installation and Commissioning
Rev. 2021 - V35
ATTENTION !
The 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.
General information on air quality
There is no universally uniform standard, which could be applied to a
VOC
sensor
(Volatile Organic Compounds). The monitored air contains a large
number of substances to which the sensor responds, and gas mixtures are
adjusted. Therefore this sensor does not act selectively, but rather reflects
the overall air quality. In principle, one also cannot state precisely what is
"bad air" or what is "good air" because this is a purely subjective sensation.
Automatic air quality calibration (permanently active)
We recommend to rinse the sensor every 7 days for 20 minutes or longer with
fresh air as a basis for automatic calibration. Within a period of approx.
3 weeks, the minimum output value for air quality is saved. During this period,
the output signal is standardised to the zero point. The maximum correction
per interval is limited here. Long-term drifts and the operation-related ageing
of the sensor element are thus completely eliminated.
Every time the device is switched on, the automatic calibration cycle restarts
and calculates a correction value across the operating period. In case of
power disruptions of less than 7 days, the calculation algorithm may be
supported with a manual calibration to adjust the correction value more
quickly.
Manual calibration of air quality
Sufficient fresh air must be provided before and after the calibration
procedure!
We recommend a fresh air supply of at least two hours before starting
manual calibration.
The calibration procedure is started by pressing the "ZERO" button
(for approx. five seconds). This is signalled via the flashing LED.
Then calibration takes place. During this phase, the LED is continuously
active and a 60 second countdown runs.
Putting in operation
After switching on the device, a self-test and tempering period follows. This
process takes around 30 - 50 minutes, depending on the ambient conditions.
Manual calibration can then be performed as an option. Make sure that no
harmful substances influence the calibration process and that the sensor is
operated in fresh air.
Switching point setting
A switching point between 10 % and 95 % of the measuring range can
be selected using the SET potentiometer. A potential-free changeover
contact is available as a switch output.
Offset
The VOC measured value can be adjusted subsequently using the offset
potentiometer. The adjusting range is ± 10 % of the measuring range.
DIP switches
KLQ - W
VOC sensitivity
DIP 1
DIP 2
LOW
OFF
OFF
MEDIUM (default)
O N
OFF
HIGH
OFF
O N
IAQ
(Indoor Air Quality)
O N
O N
Output
DIP 4
Voltage 0 -10 V (default)
OFF
Current 4...20 mA
O N
Note:
DIP 3
is not assigned!
DIP switches
KLQ - SD
VOC sensitivity
DIP 1
DIP 2
LOW
OFF
OFF
MEDIUM (default)
O N
OFF
HIGH
OFF
O N
IAQ
(Indoor Air Quality)
O N
O N
Level IAQ
(Indoor Air Quality)
VOC
1
excellent
0
...
19
%
no action required
2
good
20
...
39
%
prompt airing recommended
3
moderate
40
...
59
%
airing recommended
4
poor
60
...
79
%
increased airing required
5
unhealthy
80
...
100
%
intense airing necessary
Table according to TVOC guidelines of the German Federal
Environmental Agency to assess indoor air contamination
(Bundesgesundheitsbl - Gesundheitsforsch -
Gesundheitsschutz 2007, 50: 990–1005)
