Air quality sensor: design and use

The need: measuring air reliably

Measuring air quality is not just a matter of plugging in a probe. Cheap off-the-shelf sensors respond slowly and their readings drift. For serious use — a workshop, a livestock building, a storage room — you need a sensor that actually counts fine particles, with a short response time. That is the specification the FURGO design office set itself for this project.

The solution: the right sensor first

Several particle sensors are available on the market. After comparison, the most reliable turned out to be the PMS5003 module. Two concrete reasons:

• Laser diffraction counting. The sensor counts fine particles one by one by analysing the light they deflect. It is a true measurement, not an estimate.
• Active fan-driven sampling. Air is forced through the sensor instead of entering passively. The result: a very good response time, where cheaper alternatives lag behind.

This choice determines everything else: well-designed electronics built around a mediocre sensor will never produce a good measurement.

What FURGO built and learned

Around the PMS5003, FURGO developed the readout electronics and the sensor housing. The design details (circuit diagram, power supply) and field feedback will be covered in a dedicated publication — ask us if the subject concerns you.

The main lesson holds for all our projects: with sensors, the price gap between an entry-level component and a reliable one is small compared with the cost of a wrong measurement. You pay for the right sensor once; you suffer the wrong one every day.