Model	922 Airflow Meter	971 HumidityMeter	975 AirMeter	983 Particle Counter
Description	Combines air pressure, velocity, and flow into one rugged, easy-to-use meter	Measure humidity faster, calculate wet bulb and dew point temperatures	Measure Temperature, humidity, CO2, CO, Velocity with one Tool	Measure six particle sizes simultaneously
Measurements
Particle Size				0.3, 0.5, 1.0, 2.0, 5.0 10.0 µm
Temperature	+50°C (122°F)	+60°C (140°F)	+50°C (122°F)	+40°C (104°F)
Air Velocity	250 fpm to 16,000 fpm, 1 m/sec to 80 m/sec		50 fpm to 3000 fpm, 0.25 m/sec to 15 m/sec
CO2			5000 ppm
CO			500 ppm
Relative Humidity		5% to 95%	10% to 90%	20% to 90%
Pressure			±4000 Pascals ± 16 in H20 ± 400 mm H20 ± 40 mbar ± 0.6 PSI
Data Storage
Data Logging	99 readings	99 readings	99 (discrete), 25,000 readings (continuious)	5000 readings
Min/Max/Avg	Yes/Yes/Yes	Yes/Yes/Yes	Yes/Yes/Yes
Display Hold/ Auto Hold	Yes/No	Yes/No