KOGAST project (completed)

Harmful airborne substances such as fine dust particles, nitrogen oxides (NO_x) and ozone (O₃) endanger human health and the environment. That’s why governments monitor air quality in the EU. Most current measuring devices use electrochemical gas sensors. However, due to cross-sensitivities and environmen-tal factors, these sensors do not provide sufficiently accurate measurements. They also require significant maintenance.

A low-maintenance opto-chemical  measurement system has been designed to detect harmful air-borne substances more reliably than before.    

In the KOGAST project, which was completed at the end of 2024, we worked together with Adolf Thies GmbH and the Institute for Microsensors, -actuators and -systems (IMSAS) at the University of Bremen to develop an opto-chemical sensor system for detecting NO₂ and

O₃ and combined it with cost-effective particulate matter sensors. The system is based on LEDs, photodetectors and gas-sensitive layers. Special dyes that change color when they react with the target gas are used for the measurements. An optical waveguide is used to detect the change in color. A controllable cap protects the sensors from environmental impact when they are not being used to take measurements. The sensor system consists of several modules that are activated one after the other once the dye in one of the gas-sensitive layers is used up. This design element extends the system’s service life and reduces its maintenance requirements. The integration of particulate matter sensors and additional weather sensors is designed to prevent the measurements from being distorted and to facilitate a comprehensive analysis of the air quality.