Digital flow controllers allow users to program, record, analyze and control flow rates of various gases with a computer via an RS-485 interface. Controllers are programmable for various functions such as set point, totalizer, stop totalizer, read totalizer, totalize from preset flow, stop at preset total, auto zero and programmable flow. Extensive on-board memory enables each controller to store NIST traceable calibrations for up to 10 gases. Aalborg Instruments & Controls, Inc. 20 Corporate Drive Orangeburg, NY, 10962