The RNS Series meter is an insertion flow meter designed to offer high accuracy measurements of saturated steam flow in a variety of applications. The meters have no moving parts and are virtually maintenance-free once installed. The RNS Series is suitable for pipe sizes 6" (152 mm) and higher. All meters in this series are loop-powered devices with standard HART® communication 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 steam 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 modulates. The modulation in the carrier wave is measurable and proportional 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 low flow rates; high turndown ratios; and low pressure drop. Through the use of the internal RTD and an external pressure sensor (not included), the flow meter software will compensate for changes in pressure and temperature, to achieve an accurate mass flow measurement.