What is the advantage of using a multi-jet meter as opposed to a PD meter?
There are many reasons a Multi-Jet meter may be a better choice than a PD or Positive Displacement type meter. Please read this article for more information (link to Revisiting Measurement Technologies.pdf) Q: Why does the sweep hand continue to move on the multi-jet when the water is shut off on the meter test bench? A: Basically, for two reasons. First, inertia forces in the register mechanism continue the gear train movement in a forward direction taking up all geartrain backlash that had been biased to the other direction by flow driving torque. Second, inertial forces acting on the rotor diminish very quickly, but do not stop instantly, as they are slowed down by fluid drag; under the same effect, flow driving forces must quickly overcome fluid drag to achieve synchronous rotor speed as flow is initiated. However, these effects are self-canceling under normal use. For testing purposes, the flow should be slowed just as the test is completed for best results. Q: What happens if the
