Seven principles of flow meters

Flowmeter principle

1. Mechanical principle: instruments of this kind include differential pressure type and rotor type using Bernoulli's theorem;Using momentum theorem of impulse type, movable tube type;Using the direct mass formula of Newton's second law;Target type using fluid momentum principle;The turbine form using the angular momentum theorem;Using the principle of fluid oscillation, vortex type, vortex street type, etc.

2. Electrical principle: instruments used for this principle include electromagnetic type, differential capacitance type, inductive type and strain resistance type.

3. Acoustic principle: ultrasonic type is used for flow measurement based on acoustic principle.Acoustic (shock wave), etc.

4. Thermal principle: there are thermal formula, direct calorimetric formula and indirect calorimetric formula to measure the flow rate by using the thermal principle.

5. Optical principle: laser type and photoelectric type are instruments of this kind.

6. Atomic physics principle: nuclear magnetic resonance type, nuclear radiation type are instruments of this principle.

7. Other principles: labeling principle (tracer principle, nuclear magnetic resonance principle), relevant principles, etc.