Mass-Trak Model 810S, in ranges from 0-10 cm3/min to 0-100 Lpm, regulates flow with ±1.5% FS accuracy and ±0.25% FS repeatability. Flow setpoint adjusts locally via potentiometer and LCD, or remotely via 4-20 mA, 0-5 Vdc, or 0-10 Vdc command signal. Frictionless NC valve contains one moving part and no packing; accommodates 8-50 psid; and accepts purge and valve-close commands. Instrument outputs 2 signal lines simultaneously.