Mass Flowmeter

Inside a Red Seal Measurement mass flowmeter you will find the following components:

As liquid enters the meter, the flow divider splits the flow evenly between the two tubes. The drive coil vibrates the tubes at their resonant frequency, causing them to move in opposite directions. The inlet and outlet of the tube is held fixed as the tube vibrates in an arc about this axis. Two more coil and magnet assemblies, one at each end of the assembly, serve as sensors, generating a sinusoidal voltage proportional to the relative position of the two tubes. When there is no flow through the tubes, the tubes vibrate evenly and the output signals of these coils are in phase.

When liquid flows through the tubes, the Coriolis force causes the ends of the tubes to deflect. The resulting vibration is out of phase. This phase difference is used to determine the mass of liquid flowing through the tubes.

Other measurements can also be obtained from a mass flowmeter. These include:

  • Density
  • Gross volume
  • Net volume
  • Temperature
  • Specific Gravity