VS positive displacement flow meters are volume rate measuring sensors based on the meshing gear principle and are designed for use with liquids. Two precisely matched gear wheels are enclosed in a very accurately machined housing. Gear rotation is sensed
by a non-contacting signal pick-up system. Each tooth produces one impulse.
The space between the gear teeth, when fully enclosed on both sides by the housing, constitutes measuring chambers. Fluid flow causes the gears to rotate and the incoming flow is separated into discrete volumes within these chambers i. e. the volume of liquid passing through the unit will cause rotation of the gears by exactly one tooth pitch.This volume is known as the Volume/Impulse (Vm) and is stated in cc/Imp. It is used to define the size of a flow meter.