Particle Counters

A particle counter counts airborne particles by size; a particle monitor reports their mass. The Met One Aerocet 532 does both in one handheld unit: counts in eight channels from 0.3 to 10 µm, and PM1, PM2.5, PM4, PM7, PM10 and total suspended particulate in µg/m³, computed in as little as 60 seconds. It suits indoor air quality surveys, dust source tracing and occupational screening. Mass is converted from counts, so user K-factors (0.1 to 20.0) tune it to your dust against a reference or gravimetric method. It is not a cleanroom classifier: ISO 14644-1 sets its classes at sizes from 0.1 to 5 µm, and the records do not claim it. ERE rents and sells particle counters.

Particle counter FAQ

Particle counter or particle monitor?

Ask what you need to know: how many particles of each size (a count, for ventilation and filter checks) or how much dust mass you breathe (PM2.5 and PM10, for IAQ and workplace screening). The Aerocet 532 gives both. See our particle counter guide.

How do I keep it accurate?

Run a zero-count test weekly, check the flow monthly and send it for factory calibration once a year.

Rent or buy?

Rent for a survey or a short project; rental units are calibrated and tested before shipment. Buy if you screen routinely.