News — Senseair

Calibrating SenseAir K33 Series CO2 Sensors

SenseAir K33 ELG, BLG or ICB CO2 sensors are pre-calibrated at the factory. During normal use, they are self calibrating using the ABC algorithm. If after rough transport or handling or for statistical purposes you want to re-calibrate these sensors, this document explains how using CO2 Meter's legacy DAS software as well as how to configure sensors, view data in real-time, or manage stored logs on sensors with internal memory. Note that you are encouraged to upgrade to the newer GasLab software which currently supports all K33 sensors. Download K33 Calibration Instructions (pdf).

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Automatic Background Calibration (ABC) in Senseair CO2 Sensors Explained

Automatic Background Calibration algorithm (ABC) allows the CO2 sensor to dynamically shift its CO2 reading by a constant. It works via storing the lowest CO2 sample taken over the ABC Period and assuming that this low value is equal to a known value (the target value). It then adjusts the output of the CO2 reading by the delta between these values. This algorithm does not affect the linearization of the output signal. For example, by default ABC is enabled with an ABC Period of 180 hours, a target value of 400ppm, and a maximum delta of 30ppm. This operates under...

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K-33 Host-Initiated Data Logging

sThe K‐33 ELG/BLG sensor can be used with the Sensor Development Kit and your PC to collect data. Under standard operating conditions the sensor will only take a measurement when data collection is enabled via the hardware jumper, however using the Start Measurement command and an extension to the MODBUS protocol we can manually initiate a reading from the sensor. Please read AN104 to understand the procedure behind accessing EEPROM and RAM with the MODBUS over UART protocol. Click here to download a zip file with documentation and source code.

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SenseAir K Series Sensor UART EEPROM/RAM Access Procedure

This application note describes how to directly read and write data directly to the SenseAir K30 and K33 line of CO2 sensors. Download the application note here (pdf). Please read the MODBUS specification document before reading this document to gain a background understanding on the sensor’s implementation of MODBUS and for checksum calculating algorithms. Using these commands opens up the entire EEPROM and RAM of the sensor for UART access. It will also allow us to access the sensor using the memory locations described in the I2C guide.

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Interfacing a K30 Sensor with Arduino Development Kit via I2C

The Arduino makes an ideal platform for prototyping and data collection with the SenseAir K series of CO2 sensors. Arduino CO2 Sensor Application Note From Wikipedia: Arduino is a single-board micro controller to make using electronics in multidisciplinary projects more accessible. The hardware consists of an open-source hardware board designed around an 8-bit Atmel AVR microcontroller, or a 32-bit Atmel ARM. The software consists of a standard programming language compiler and a boot loader that executes on the micro controller. Arduino boards can be purchased pre-assembled or as do-it-yourself kits. Hardware design information is available for those who would like...

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