Contains a laser and sensor. Appears to detect light scattered by particles that pass the laser beam. Air forced through channel by a fan.

Manual

9600 baud, 8N1.

Output is small particle count, large count, CRLF.

“This data is output every minute and the counts represent the average concentration over the past minute. The units are – counts/100 per cubic foot. In the above example, the output of 675 would mean the average concentration over the past minute was 67,500 particles per cubic foot.” (manual)