Liquid flow transmitter VHS

The VHS flow transmitter measures the flow using the volumetric principle, and is suitable for fluid, viscous, lubricant media (e.g. lubricating oil). If the material for the VHS is selected appropriately, aqueous fluids such as soaps, pastes, and emulsions with nonabrasive characteristics can also be measured, as long as they have sufficient lubricity. Because of the volumetric functioning principle, the device is almost completely independent of viscosity. The VHS system consists of two interlacing screws which run in opposite directions, driven by the flowing medium. A magnetically pre-tensioned Hall sensor positioned outside the flow space detects the screw flanks, and creates a frequency signal proportional to the flow. Here, two pulses correspond to one revolution of the screws, and therefore to a specific measured volume (see data table) There are no magnets in the flow space. A push-pull transistor output, an A / B output or a two wire output are available as signal output. The push-pull output can as desired be switched as a PNP or an NPN output, and emits a frequency proportional to the flow rate. The A / B output consists of two push-pull outputs, whose signals are phase-shifted by 90 °. This makes it possible to determine the direction of flow using the bidirectionally driven sensor. The 2 wire model represents the pulse as two different currents, and has the advantage of reduced wiring effort. Alternatively, it is possible to use add-on electronics with signal processing, in the series OMNI, FLEX and LABO. The device bodies are made of aluminium, and the connections either of aluminium (achieves PN 160 bar) or steel (achieves PN 350 bar).