The RWG and RWBG Series meters are wafer-style in-line flow meters designed to offer high accuracy measurements with extremely low pressure drop. The meters have no moving parts and are virtually maintenance-free once installed. The RWG series is suitable for most gas types. The RWBG series is similar in construction but optimized for low-pressure “BioGas” applications, typically CH4 + CO2 mixtures. All meters in these series are loop-powered devices with standard HART® communications for ease of field programming and system integration.

An everyday example of a vortex shedding phenomenon is a flag waving in the breeze: the flag waves due to the vortices shed by wind moving across the flagpole. Within the flow meter, as flowing gas moves across the tiny strut or “bluff bar”, vortices are also shed but on a smaller scale. The meter transmits an ultrasonic beam through the vortex pattern downstream of the strut. As vortices are shed the carrier wave of the ultrasonic signal is modified. This change in the carrier wave is measurable and moves in proportion to the number of vortices shed.
Digital processing enables the vortices to be counted, and this value is converted into a velocity. Software converts velocity into a volumetric flow rate, in units of measure selected by the operator. Racine Vortex flow meters utilize the smallest strut in the industry, which allows for high levels of sensitivity; superior performance at very low flow rates; high turndown ratios; and low pressure drop. Through the use of an internal RTD and an external pressure sensor (optional), the flow meter software will compensate for changes in pressure and temperature, to achieve an accurate mass flow measurement.