## Positive Displacement Flow Meters

Positive Displacement flow meters are the only flow measuring instrument that can directly measure the volume of liquid passing though the flow meter. These meters achieve this by trapping small amounts of fluid between rotating components within a high precision chamber.  A basic analogy would be holding a bucket below a tap, filling it to a set level, then quickly replacing it with another bucket and timing the rate at which the buckets are filled (or the total number of buckets for the “totalized” flow).