You could try searching for "air quality sensor" on aliexpress. I have experience with this one [0] which purports to measure particles in various units, and I

You could try searching for "air quality sensor" on aliexpress. I have experience with this one [0] which purports to measure particles in various units, and I suspect it to be 20-30% inaccurate. The figure it gives for humidity is about 10-20% off from other cheap devices, but the sensor might be more accurate given that the device runs on USB and emits a non-zero amount of heat, which affects the local measurement. It supports data exports in real time over USB serial. [0] https://www.aliexpress.com/item/4001127955294.html https://www.aliexpress.com/item/4001127955294.html