A Low-Cost, Direct Reading Instrument Used for Both Air Velocity & Static Pressure TestsThe Model 641B Air Velocity Transmitter uses a heated mass flow sensor suitable for dirty air flow applications. It has user-selectable ranges from 250 FPM (1.25 MPS) to 2000 FPM (10 MPS).
Service : Air and compatible, non-combustible gases.
Accuracy : 5% FS process gas: 32 to 122°F (0 to 50°C); 6% FS process gas: -40 to 32°F & 122 to 212°F (-40 to 0°C & 50 to 100°C).
Response Time : Flow: 1.5 s to 95% of final value (output filter set to min).
Temperature Limits:Process : -40 to 176°F (-40 to 80°C).
Ambient : 32 to 140°F (0 to 60°C).
Humidity Limit : Non-condensing.
Power Requirements : 12 to 35 VDC, 10 to 16 VAC. 1.5 A rating required on supply due to initial power surge drawn by transmitter.
Output Signal : 4 to 20 mA, isolated 24 V source, 3 or 4-wire connection.
Output Filter : Selectable 0.5-15 s.
Loop Resistance : 600 Ω max.
Current Consumption : 300 mA max*.
Electrical Connections : Screw terminal.
Enclosure Rating : Designed to meet NEMA 4X (IP66) for non-LED skus only.
Mounting Orientation : Unit not position sensitive.
Weight : 12.6 oz (357.2 g).*A brief current transient exceeding 300 mA may be seen on startup.
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