Contrec 515 Add/Subtract Flow Computer (FA02)

The Contrec Model 515 (Application FA02) is an add/subtract flow computer for mass flow, built to take two independent flow channels and add or subtract between them to give a combined or net mass total. It’s the mass-metering version of the standard 515 add/subtract application, used on process lines where you need to balance or aggregate mass flow across two measurement points rather than reading a single meter on its own.

The two input channels accept a wide range of frequency signals (millivolt, reed switch, Namur proximity, open collector) or scaled analogue signals, and it can take a re-transmitted signal from another flow computer on the network on one channel while reading a field flowmeter directly on the other, if that’s how your setup is wired.

In actual application, this application code is normally paired with two mass flow measurement points feeding into one custody transfer or balancing total – for example a header split into two lines, or a supply and return. The 515 has an onboard adjustable transducer excitation supply so you can power the field sensors directly, plus programmable high and low alarms, 4-20mA retransmission, and dual RS-232/RS-485 Modbus RTU ports so it reports into your existing SCADA or DCS setup.

Before we quote this, we would normally check the signal type on each channel (frequency or analogue), whether you need addition or subtraction between the two, and what alarm and output signals your control system needs. Hope this helps.