The Fradenprobe FP-128 from CleanAlert LLC, Oberlin, OH, is a mass air flow sensor based on thermoanemometer technology that can measure air velocities up to 2500 fpm. Features include reading accuracy of ±5% of reading from 200–2500 fpm and ±5% of reading ±10 fpm for velocities <200 fpm; <20 s response time from 0–95% of air flow rate; <30 s power-on warm-up time; and temperature ranges of –18°C to 50°C (operating) and –40°C to 85°C (storage). Outputs include a linear 0.5–4.5 VDC output and a digital PWM output. The 9 in. by 0.5 in. probe is suited for use in HVAC system controls, large building automation, data center management, and oil/gas burner control applications.