CO2 Engine K30
Sensor Module and OEM Platform
The K30 sensor platform CO2 Engine® K30 can be customized for a variety of sensing and control applications. This platform is designed to be an OEM module for built-in applications in a host apparatus, and hence should be optimized for its tasks during a dialog between SenseAir and the OEM customer. This document is to be considered as the starting point for such a dialog.
Single-point Calibration restore switch Din1
For highest possible accuracy, the sensor can be re-calibrated just before the important measurement is to be carried out. This is possible to do by a qualified operator, provided that the sensor is exposed to a reference gas, which by default should contain exactly 400 ppm CO2. This number can be selected to any other value of preference using serial interface and PC software provided by SenseAir.
During a calibration process the sensor must be carefully exposed to the calibration gas in a manner that assure no dilution air of the reference gas from the ambient, and that no overpressure is created in the sensor sample cell. One way to achieve this is to position the sensor in a deep and soft plastic bag and flush the reference gas inside this bag for a while.
Creating an electrical shortcut between the two holes labeled Din1 actuates the calibration process. A closure here will ground one of the micro-controller I/O pins. As soon as the micro-controller detects this manually grounded switch terminal, a new zero constant sensor parameter is calculated replacing the old parameter, so as to push the current sensor reading to what is being defined for the reference gas (default = 400 ppm CO2).
If the operator leaves the sensor with Din1 closed for some period of time, the sensor will continue to recalibrate for the 400 ppm target value until the switch closure eventually is released.
Zero Calibration restore switch Din2
The Din2 switch operates exactly in the same way as the Din1 switch, but assumes that the reference gas contains no Carbon dioxide at all, such as Nitrogen, for instance. Hence, a calibration executed by shorting the Din2 switch performs a true zero point calibration adjustment.