Dwyer 641-6 Air Velocity Transmitter measures air velocity and temperature. It has an operating temperature range of -40 to 212°F (-40 to 100°C) for process temperature and 32 to 140°F (0 to 60°C) for ambient temperature. The accuracy of the transmitter is ±3% FS for process gas temperature ranging from 32 to 122°F (0 to 50°C) and ±4% FS for process gas temperature ranging from -40 to 32°F & 122 to 212°F (-40 to 0°C & 50 to 100°C). It requires a power supply of 12 to 35 VDC or 10 to 16 VAC with a 1.5 A rating to handle the initial power surge. The response time is 1.5 seconds to reach 95% of the final value. The enclosure meets NEMA 4X (IP66) standards for non-LED models. It has a resolution of 1 FPM and 0.01 MPS with screw terminal electrical connections. The output signal is 4 to 20 mA with an isolated 24 V source and can be connected using 3 or 4 wires. The service is suitable for clean air and compatible non-combustible gases. It has a 4-1/2 digit red LED display. The unit is not position sensitive, but the probe must be aligned with the airflow. The pressure limit is 100 psi (6.89 bar) max and it has a 1/2" male NPT process connection. The loop resistance is 600 Ω max and the current consumption is 300 mA max. An output filter can be selected between 0.5-15 seconds.