Development of a Modular Gas Monitoring System (GMS) for Real-Time Quality Assessment in Gaseous Radiation Detectors

This report presents the design, development, and characterization of a Gas Monitoring System (GMS) for real-time quality assessment in gaseous detectors, developed within the DRD1 collaboration. The system measures humidity, oxygen concentration, gas pressure, gas flow rate for different gas mixtures, and environmental parameters (temperature, atmospheric pressure, humidity).
It is built around a Raspberry Pi 5, using InfluxDB for data storage and Grafana for visualization, and is designed to be portable, autonomous, easy to assembly, and cost-effective (below 5,000 CHF).

A central result of the study is the recommendation to calibrate flow sensors for each specific gas mixture, as standard manufacturer calibrations (air-based) proved insufficient. The report provides calibration fits for eight commonly used mixtures, and emphasizes that new mixtures should undergo dedicated calibration, with results shared in the open repository.

The entire project is published as open source, with complete documentation, bill of materials, production files, and assembly instructions available to the detector community. This makes the GMS both reproducible and adaptable to different research groups and detector technologies.