Positive displacement (PD) volumetric flow rate meter instrumentation for directly measuring the volume of a substance that has transferred over a period of time.
There are many different principles of design used for manufacturing positive displacement flow meter. Principally most are producing a way of breaking up the flow into countable fixed dimension packets, using dynamic chambers as the flow passes through the PD flow meter.
The dynamic chambers have precise dimensions and therefore it is possible to accurately determine the amount of fluid transferred by each chamber. The number of chambers filled are counted over time, and thus the volumetric flow rate can be determined by multiplying the total number of counts by the volume of the chamber, and dividing by the total time.
A positive displacement volumetric flow meter is an instrument measure directly the volume of a substance which is passing through a specific location in a set period of time.
Positive displacement volumetric flow meters can provide an instantaneous analogue, digital or pulse output of the volumetric flow rate.
A PD volumetric flow meter may also include additional electronics such as a digital indicator for displaying the total volume measured to date.