The new Series 641 Air Velocity Transmitter is the ideal instrument for monitoring air flow. This transmitter uses a heated mass flow sensor which allows for precise velocity measurements at various flow rates and temperatures. The 641s 16 field selectable ranges provides it the versatility to be selected for several air flow applications. The optional LED produces a complete, low-cost solution for local indication of air flow. Ranges to 15,000 FPM or 75 MPS Optional Bright LED Display Easy Push Button Set-up Compact Housing 4-20 mA Output Digital Filter for Signal Damping 18 (457.2 mm) probe length with LED display