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 LABO-xxx-s electronics fitted to the device make available an
electronic switching output (push-pull) with adjustable
characteristics (minimum/maximum) and hysteresis, which
responds when an adjustable limit is fallen short of or exceeded.

If desired, the switching value can be set to the currently existing
flow using "teaching".
Models with analog or pulse output are also available (see separate
data sheets).