The Contrec Model 515 (Application GN03) is built for natural gas flow measurement using differential pressure mass meters, including installations with stacked DP transmitter arrays to widen the usable flow range. It runs the generic DP flow equations referenced to the actual conditions the flowmeter was calibrated at, so the reading tracks the real orifice or DP element behaviour rather than a generic textbook curve.
Gas compressibility and live density are worked out using the AGA-8 Detailed Characterization Method, and gross heating value is calculated in line with ISO 6976 and GPA 2172-96. This is the same calculation basis used for fiscal and custody transfer gas metering, so the numbers this unit produces are suitable for billing and energy accounting purposes, not just internal monitoring.
In actual application, this application code is normally paired with a DP transmitter (or a stacked pair for extended turndown) plus a temperature and pressure input for live gas conditions. The 515 has an onboard adjustable transducer excitation supply, so in many cases you don’t need a separate power supply for the field transmitters. Output side, it gives you analogue retransmission, a scaled pulse output, and dual serial ports for Modbus RTU, so it slots into most existing SCADA or DCS setups without extra conversion hardware.
Housing is IP65 rated with a backlit alphanumeric display, so it holds up fine in a typical outdoor gas metering skid or plant utility area.
Before we quote this, we would normally check the DP transmitter range and calibration reference conditions, whether it’s a single or stacked transmitter setup, the gas composition (for the AGA-8 calculation), and what output signals your control system needs. Hope this helps.
