Positive displacement flow meter

Positive displacement flow meter uses a fixed small volume to repeatedly measure the volume of fluid passing through a flowmeter. Therefore, there must be a standard volume of space inside the positive displacement flowmeter, which is usually called the "metering space" or "metering room" of the positive displacement flow meter. This space consists of the inner wall of the meter housing and the rotating parts of the meter.
The working principle of the positive displacement flowmeter is: when the fluid passes through the flowmeter, there will be a certain pressure difference between the inlet and outlet of the flowmeter. The rotating part of the flow meter (rotor for short) rotates under this pressure difference and pushes the fluid from the inlet to the outlet. In this process, the fluid repeatedly fills the "metering space" of the flowmeter, and then is continuously sent to the outlet. For a given flowmeter, the volume of the metering space is determined as long as the number of rotations of the rotor is measured. You get a cumulative value of the volume of fluid going through the meter.
As the fluid passes through the flowmeter, there is a pressure difference between the inlet and outlet of the flowmeter. The rotating part of the flow meter (rotor for short) rotates under this pressure difference and pushes the fluid from the inlet to the outlet. In this process, the fluid repeatedly fills the "metering space" of the flowmeter, and then is continuously sent to the outlet. For a given flowmeter, the volume of the metering space is determined as long as the number of rotations of the rotor is measured. You get a cumulative value of the volume of fluid going through the meter.

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