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What is the working principle of the flowmeter?

Ultrasonic flowmeter adopts the principle of time difference measurement: one probe transmits the signal through the pipe wall, the medium and the other side of the pipe wall, and is received by the other probe. At the same time, the second probe also transmits the signal and is received by the first probe. . Due to the influence of the flow velocity of the medium, there is a time difference Δt between the two. According to the calculation, the conversion relationship V=(C2/2L)×Δt between the flow velocity V and the time difference Δt can be obtained, and the flow rate value Q can be obtained.

Turbine flowmeter is the main type of velocity flowmeter. When the fluid to be measured flows through the turbine flowmeter sensor, under the action of the fluid, the impeller is forced to rotate, and its rotational speed is proportional to the average flow velocity of the pipeline. At the same time, the blade periodicity The magnetic flux generated by the electromagnet is cut and the magnetic flux of the coil is changed. According to the principle of electromagnetic induction, a pulsating potential signal, that is, an electric pulse signal, is generated in the coil, and the frequency of the electric pulsation signal is proportional to the flow rate of the fluid to be measured.

The measuring part of the elliptical gear flowmeter is mainly composed of two intermeshing elliptical gears and their outer casings, and the elliptical gears generate a working moment to rotate under the pressure difference of the measured medium. The wheel 1 and the wheel 2 are alternately driven by one to rotate the other, and the measured medium is discharged from the inlet to the outlet once in a half-moon volume. Therefore, the amount of the measured medium discharged per revolution of the oval gear flowmeter It is 4 times the volume of the half moon, so that the volume flow Q through the elliptical gear meteormeter can be derived.

The working principle of the open channel flowmeter is to use ultrasonic technology to measure the fluid level and then calculate the flow through the microprocessor inside the instrument. Because of the non-contact measurement, the open channel flowmeter can be used in harsh environments. The open channel flowmeter emits and receives ultrasonic waves under the control of the microcomputer, and calculates the distance of the open channel flowmeter from the measured liquid surface according to the transmission time, thereby obtaining the liquid level height. Since there is a certain proportional relationship between the liquid level and the flow rate, The liquid flow rate Q can be finally obtained according to the calculation formula.

The unit m3/h is commonly used in engineering. It can be divided into flow rate and total flow. The instantaneous flow rate is the amount of the effective cross section of the closed pipe or open channel per unit time. The material flowing through can be gas. Liquid, solid; cumulative flow is the cumulative amount of fluid flowing through a closed pipe or open channel at a certain time interval (one day, one week, one month, one year). The instantaneous flow rate can also be used to calculate the cumulative flow rate by integrating the instantaneous flow rate, so that the instantaneous flow meter and the cumulative flow meter can also be converted into each other.

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