The Types of Flowmeter You Should Know
The instruments for measuring fluid flow are collectively referred to as flow meters or flow meters. Flow meters are one of the important instruments in industrial measurement. With the development of industrial production, the requirements for the accuracy and range of flow measurement are becoming higher and higher, and the flow measurement technology is changing with each passing day. In order to adapt to various uses, various types of flow meters have come out one after another. At present, more than 100 kinds of flow meters have been put into use. Each product has its specific applicability and limitations. There are many methods to classify the flowmeter, such as classification according to the measurement principle or the structure principle of the flowmeter. According to the actual situation of the current flowmeter products and the structure principle of the flowmeter, it can be roughly summarized into the following types:
Classification according to measurement principle:
- Mechanical principle: Instruments belonging to this kind of principle include differential pressure type and rotor type using Bernoulli's theorem; Impulse type and movable tube type using momentum theorem; Using the direct mass formula of Newton's second law; Target type using the principle of fluid momentum; Turbine type using angular momentum theorem; Vortex type and vortex street type based on fluid oscillation principle; Pitot tube type, positive displacement type, weir and trough type utilizing total static pressure difference, etc.
- Electrical principle: the instruments used for this principle include electromagnetic type, differential capacitance type, inductance type, strain resistance type, etc.
- Acoustic principle: ultrasonic type, acoustic type (shock wave type), etc. are used for flow measurement.
- Thermal principle: there are thermal type, direct calorimetric type, indirect calorimetric type, etc. that use thermal principle to measure flow.
- Optical principle: laser and photoelectric instruments belong to this kind of principle.
- Original physical principle: nuclear magnetic resonance and nuclear radiation instruments belong to this kind of principle
- Other principles: marking principle (tracer principle, nuclear magnetic resonance principle), correlation principle, etc.