SRC-C1
Doc: 70-07-0220, V1.2, 20170131, Subject to alteration, ©Vector Controls GmbH, Switzerland, www.vectorcontrols.com
Page 5
Calibration
The default sensor OEM unit is maintenance free in normal environments thanks to the built-in self-correcting ABC algorithm
(Automatic Baseline Correction). This algorithm constantly keeps track of the sensor’s lowest reading over a 7 days’ interval
and slowly corrects for any long-term drift detected as compared to the expected fresh air value of 400 ppm CO2.
Rough handling and transportation might, however, result in a reduction of sensor reading accuracy. With time, the ABC
function will tune the readings back to the correct numbers. The default “tuning speed” is however limited to about 30
ppm/week. For post calibration convenience, in the event that one cannot wait for the ABC algorithm to cure any calibration
offset, jumper 3 is provided for the operator to choose calibration options. There are two calibration possibilities: 0 ppm and
400 ppm. Only one calibration needs to be performed.
Calibration to 0 ppm with CO2 free gas
1.
Connect the sensor on top with a tube (soft tubing 2 x 4 mm) and a nipple
(nylon tubing 30 x 0.8 x 2.2 mm), see picture on the right side. There are 2
alternative positions for nipple attachment.
2.
Let a gas mixture which is free from CO2 (i.e. Nitrogen or Soda Lime CO2
scrubbed air) flow into the sensor through the applied tube. The flow shall be in
the range of 0.3 – 1.0 liter/minute during 3 minutes. Keeps the gas mixtures
flowing during the whole procedure.
3.
Connect OPU-S, Login and set IP08 = 1 and exit configuration mode. The air
quality LED will blink in red color alternating with the status led in 2 second
intervals.
4.
The sensor will now wait for a stable concentration. Once the calibration has
been executed, the status LED will show constant RED and the green air quality
led will blink for 10s if successful. If calibration is not successful (no stability of
concentration for 5 min, no communication with sensor) the red air quality led
will blink instead and the sensor enters error mode. Recalibrate or restart device
to stop error mode.
5.
Verify the zero calibration using the OPU-S or the analog outputs. They should show 0 ppm CO2.
6.
Do not breathe on the sensor!
Calibration to 400 ppm (Fresh air)
1.
Expose the active sensor for at least 5 minutes to fresh outside air.
2.
Connect OPU-S, Login and set IP08 = 2 and exit configuration mode. The air quality led will blink in green color
alternating with the status led in 2 second intervals.
3.
The sensor will now wait for a stable concentration. Once the calibration has been executed, the status LED will show
constant RED and the green air quality led will blink for 10s if successful. If calibration is not successful (no stability
of concentration for 5 min, no communication with sensor) the red air quality led will blink instead and the sensor
enters error mode. Recalibrate or restart device to stop error mode.
4.
Verify the calibration using the OPU-S or the analog outputs. They should show 400 ppm CO2.
5.
If unsuccessful, wait at least 1 minute before repeating the procedure again. Make sure that the sensor environment
is steady and calm!
