Functions

Description

➢CO2 adjustment

o1-point or up to 9-point CO2 adjustment/calibration

oReset to the factory adjustment

Note 1:

In general, it is essential to pay attention that the reference value as well as the measured value. Make sure that the conditions are stable before carrying out a calibration or an adjustment.

Note 2:

The data acquisition need to be executed in real time. Meaning that the CO2 levels acquired must be applied at the same moment.

Calibration values (e. g. a calibration table with index and measured values done in a separate calibration procedure) cannot be used for a data acquisition at a later date. The reason is the missing pressure compensation data.

➢Simulator mode

Is used to output fixed values for CO2. The output value can be configured.

➢Automatic calibration

The automatic calibration is carried out via a baseline correction (ABC), where the baseline can be defined and the measurement period can also be defined.

oCan be set on/off (standard: on)

oBaseline can be set (standard: 400 ppm)

oPeriod can be set (standard: 8 days)

The functionality of the ABC feature:

Any drift of the sensor caused by the light source or the light receiver or other influences is corrected periodically by an automatic 1-point correction. This correction works as an offset.

Following the assumption that the lowest possible level at ambient air is 400 ppm (region dependent), the sensor logs internally the lowest measured value during a defined period (default 8 days).

After the defined period, the sensor adds an offset of all futures measured values are corrected.

An example. If after 4 days, the measured value drops below 400 to minimum 360 ppm then the sensor adds the difference of 40 ppm to all future measured values after 8 days (end of ABC period). This is only working if it can be guaranteed that the ambient gets fresh air at least once a week.

Period adaptation: If the application gets fresh air less than once a week (e. g. special ambient of greenhouses), the period can be adapted to a period where fresh air will be seen by the CCD.

Baseline adaptation: The level of 400 ppm might be changed only if the application can guarantee that the minimum possible level is known. Otherwise, we do not advise to change this baseline.

➢CO2 range

The CO2 range can be changed between 0…2’000 pmm, 0…5’000 ppm and 0…10’000 ppm.

➢Measurement period

The measurement period is set to 16 seconds. It is the lowest limit for the CCD and can be increased.

➢CO2 filter

The filter settings can be changed:

oFilter and APC: Filter and automatic pressure compensation

oFilter: Only filter is on

oAPC: Only automatic pressure compensation is on