Principle analysis of various types of flowmeters
(1) Principles of mechanics: Instruments belonging to such principles have differential pressure and rotor type using Bernoulli's theorem; impulse type and movable tube type using momentum theorem; direct mass type using Newton's second law; The target type of the momentum principle; the turbine type using the angular momentum theorem; the vortex type using the principle of fluid oscillation, the vortex type; the pitot tube type using the total static pressure difference; the volumetric type, the enthalpy, the trough type, and the like.
(2) Electrical principle: The instruments used for such principles are electromagnetic, differential capacitive, inductive, strain resistant, etc.
(3) Acoustic principle: Ultrasonic type, acoustic type (shock wave type), etc. are used for flow measurement using the acoustic principle.
(4) Thermal principle: The heat, direct thermal, indirect calorimetry, etc., which measure the flow using the thermal principle.
(5) Optical principle: laser type, photoelectric type, etc. are instruments belonging to such principles.
(6) Originally based on physical principles: nuclear magnetic resonance, nuclear radiation, etc. are instruments of this type.
(7) Other principles: Marking principle (trace principle, NMR principle), related principles, etc.
Product advantage and preservation
The vortex flowmeter adopts micro-power high-tech, and can be operated continuously by lithium battery for more than one year, which saves the purchase and installation cost of cables and display instruments, and can display instantaneous flow and accumulated flow on the spot. The temperature-compensated integrated vortex flowmeter also has a temperature sensor that directly measures the temperature of the saturated steam and calculates the pressure to show the mass flow of the saturated steam. The temperature and pressure compensation integrated type has a temperature and pressure sensor. The gas flow measurement can directly measure the temperature and pressure of the gas medium, thereby indicating the volumetric volume flow of the gas.
In order to prevent accidental damage to the instrument, please keep the packaging status of our company when it is shipped to the user.
After the instrument arrives, it should be installed in time to avoid the insulation performance of the flow converter being reduced due to unexpected factors, and the metal parts are corroded. If you need to store for a long time, please observe the following:
1. When storing, try not to unpack.
2. The storage location should have the following conditions:
3. With rainproof and waterproof facilities
4. Not susceptible to mechanical vibration or shock
5. The instrument should be stored in the temperature and humidity ranges listed in the table below. The ideal temperature and humidity is 25 ° C, 65%
6. Ambient temperature -20 ° C ~ +60 ° C
7. Relative humidity 5% to 90%
Ultrasonic flowmeter
The ultrasonic flowmeter is designed based on the geometrical principle that the velocity of the ultrasonic wave propagating in the flowing medium is equal to the average flow velocity of the measured medium and the velocity of the acoustic wave itself. It is also measured by the flow rate to reflect the flow rate. Although the ultrasonic flowmeter appeared only in the 1970s, it is very popular because it can be made into a non-contact type and can be connected to the ultrasonic water level gauge for opening flow measurement without disturbing or resisting the fluid. There are promising flow meters.
Ultrasonic Doppler flowmeters fabricated using the Doppler effect have received widespread attention in recent years and are considered to be ideal gauges for non-contact measurement of two-phase flow.
Fluid oscillating flowmeter
The fluid oscillating flowmeter is designed based on the principle that the fluid will oscillate when flowing under specific flow conditions, and the frequency of the oscillation is proportional to the flow velocity. When the flow cross section is constant, the flow rate is proportional to the flow volume of the pilot volume. Therefore, the flow rate can be measured by measuring the oscillation frequency. This flowmeter was developed and developed in the 1970s. Because it combines the advantages of non-rotating components and pulsed digital output, it has a promising future. At present, typical products include vortex flowmeters and spiral vortex flowmeters.