Profile: TSI Incorporated deals with the design and production of precision measurement instruments. Our product categories are combustion gas analyzers, mass flowmeters, particle counters & detectors, PIV systems and aerosol generators & dispersers. The Velocicalc® air velocity meters measure air velocity and temperature. They measure face velocity in fume hoods & spray booths, or for IAQ and ventilation system checks. The Certifier® air velocity calibrator, calibrates probed air velocity meters or transducers at velocities as low as 30 ft/min, and as high as 9000 ft/min.