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
non-abrasive 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, every pulse corresponds to a specific measured
volume. There are no magnets in the flow space.
The FLEX transducer on the sensor has an analog output
(4..20 mA or 0..10 V) and one switching output, which can be
configured as a limit switch for monitoring minimal or maximal, or
as a frequency output or pulse output.

The switching output is designed as a push-pull driver, and can
therefore be used both as a PNP or an NPN output. The state of
the switching output is signalled with a yellow LED in the switching
outlet; the LED has all-round visibility.

The sensor is configured in the factory, or alternatively this can be
done with the aid of the optionally available ECI-1 device
configurator (USB interface for PC). A selectable parameter can be
modified on the device, with the aid of the magnet clip provided. In
this case, the current measured value is saved as the parameter
value. Examples of these parameters are the switching value or the
metering range end value. The stainless steel electronics housing
is rotatable, so it is possible to orient the cable outlet after
installation.