The 640B absolute pressure controller is a self-contained, compact, closed-loop electronic pressure control system containing a Baratron® capacitance manometer, normally closed proportioning control valve, and closed-loop control electronics. Electrically similar to a standard MFC, the 640B is powered by ±15 VDC at only 200 mA, permitting use with standard power supply and display electronics. The pressure output and input control signals are linear 0-5 or 0-10 VDC. Two trip points with LED status indicators are for use as simple on/off process limits.