The Series 641 air velocity transmitter uses a heated mass flow sensor for measuring velocity at various flow rates and temperatures. Units have an adjustable span and digital filter for signal damping. Each unit has 16 field-selectable ranges in fpm or mps. Stocked probe lengths are 6, 12, and 18 inches (15.2, 30.5, and 45.7 cm); other probe lengths are available on request. The LED for local indication of airflow is optional. It has a pressure limit of 100 psi (6.89 bar) maximum, and a 4-20 mA output.

Dwyer Instruments Inc., P.O. Box 373, Michigan City, IN 46361; 219-879-8000; 219-872-9057 (fax);;

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