1, mechanical principle: the instruments belonging to this principle include differential pressure type and rotor type using Bernoulli theorem; Pulse type and moving tube type using momentum theorem; Using the direct mass formula of Newton's second law; Target types using the principle of fluid momentum; Turbine formulas using angular momentum theorem: vortex type, vortex street type, etc. Using the principle of fluid oscillation.
2. Electrical principle: The instruments used in this principle include electromagnetic, differential capacitance, inductance and strain resistance.
3. Acoustic principle: Ultrasonic waves and sound waves (shock waves) are used to measure the flow.
4. Thermal principle: there are calorimeters, direct calorimeters and indirect calorimeters. Measure the flow by thermal principle.
5. Optical principle: both laser and photoelectric instruments belong to this principle.
6. Principle of atomic physics: Both nuclear magnetic resonance vibration type and nuclear radiation type are instruments belonging to this principle.
7. Other principles: labeling principle (tracer principle, nuclear magnetic resonance principle), correlation principle, etc.
Extended data
Market factors of flowmeter:
Driving factors According to the forecast of the International Energy Agency (IEA), from 2007 to 2030, the global investment in energy infrastructure will be $26.0 trillion (in 2007 dollars). In the long run, the foreseeable energy investment will bring great development space for the application of flowmeter in oil, natural gas and energy industries.
Facing the fierce competition environment, in order to meet the global demand of energy saving and emission reduction, more and more electronic technologies are introduced into the flowmeter, which makes the flowmeter have self-diagnosis function and can communicate with the production control layer better. The improvement of performance better meets the needs of industry users and creates a larger market application space for flowmeter.
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