Germany · Stuttgart · See the Germany profile · See the Stuttgart profile
Evidence: Descriptive / self-reported Top 39% 71/100 · Ask Evidence Copilot about this practice
Since 2015, OK Lab Stuttgart's open-source, ~€30 particulate-matter sensor kit has been rebuilt by volunteers into tens of thousands of live stations across dozens of countries — though independent lab tests find its accuracy solid for PM2.5 but weaker for coarser PM10 particles.
Sensor.Community (originally luftdaten.info) began in 2014-2015 when volunteers at Open Knowledge Lab Stuttgart, unable to obtain fine-grained particulate-matter data from the city, decided to build their own low-cost sensors, settling after a year of prototyping on the SDS011 particulate sensor packaged into an open-hardware kit costing roughly €30.
The kit is designed to be self-soldered and mounted on a windowsill, with all readings published as open data on a live map refreshed every 2.5 minutes; the design spread through direct replication by volunteers rather than institutional rollout.
Early reports counted around 5,000 self-built kits concentrated in Germany, the Netherlands and Bulgaria; by the mid-2020s, third-party aggregator AQICN was tracking over 35,000 live Sensor.Community stations worldwide. Independent laboratory evaluation (Budde et al.) of the core SDS011 sensor found it performs well for fine PM2.5 particles but is markedly less reliable for coarser PM10, with inter-unit error rates as high as 10-37% for PM10 versus 9-24% for PM2.5.
The sensor's accuracy limitations restrict its use for regulatory-grade compliance monitoring, but the network still functions as a valuable indicator of relative local air-quality patterns and a training ground for civic-tech chapters worldwide.
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Where this practice's information was retrieved from, and when.
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