Contrec – 415

Frequency Input Gas and Steam Computer

415 Steam and Gas Flow Computer with temperature and pressure correction

The 415 Steam and Gas Flow Computer incorporates the following compensation equations for gas and vapours:

Ideal Gas Law using temperature and pressure correction, but where compressibility correction is not required.

General Gases where compressibility is calculated using the Redlich-Kwong¹ state equation. This equation is suitable for gases which have known properties, and information on common industrial gases is provided in the operating manual.

Natural Gas using the NX-19² equation to calculate super compressibility.

Steam Equations for both saturated and superheated steam. Mass and energy flow rates are calculated using standard equations to determine the specific weight and enthalpy of steam.


The backlit alphanumeric display simplifies programming and provides a clear indication of all parameters, as well as engineering units. The 415 is fully programmable and all operating parameters are entered via the front panel keypad.

The instrument is available with direct RTD input (415R) or with 4-20mA temperature input (415A). Both accept a 4-20mA pressure input.


Inputs from a wide range of flowmeters are accepted, including vortex, turbine, orifice plate, averaging pitot tubes, wedges and target flowmeters. Also, where two differential pressure transmitters are used across an orifice or similar device, to increase the measured flow range, both DP transmitter inputs are accepted and scaled separately with automatic crossover.