Metal tube float flow meters for which fluids

　　The metal tube float flowmeter has two states: display state and setting state. In the display state, the cumulative amount, instantaneous amount and self-test results can be displayed by pressing the button. In the setting state, various parameters can be set. These two states can be switched by pressing the SET key for more than 3 seconds and then releasing it. The key operation should be more than 0.5 seconds, otherwise the instrument will not respond. There are three keys on the panel: SET, SHIFT and INC.

　　In the display state: press the SHIFT key: cumulative amount → instantaneous amount → self-test result → cumulative amount; press the INC key: cumulative amount ← instantaneous amount ← self-test result ← cumulative amount The metal tube float flowmeter is suitable for a wide range of fluids, but Not suitable for measuring low Reynolds number fluids. At low Reynolds numbers, the Strouhal number changes with the Reynolds number, the linearity of the instrument becomes poor, and the fluid viscosity is high, which significantly affects or even hinders the generation of vortices. At the same time, there are requirements for the dirty properties of the fluid. The erosion of the vortex generator by fluid containing solid particles will produce noise and wear on the vortex generator. If the short fibers contained are wrapped around the vortex generator, the instrument coefficient will be changed. The applications of metal tube float flow meters in miscible fluids are as follows:

　　① It can be used for gas-liquid two-phase flow containing dispersed and uniform tiny bubbles, but the volumetric gas content should be less than 7%~10%. If the volumetric gas content exceeds 2%, the instrument factor should be corrected.

　　② It can be used for gas-solid and liquid-solid two-phase flows containing dispersed and uniform solid particles with a content of no more than 2%.

　　③ It can be used for the flow of two groups of immiscible liquids (such as oil and water). Pulsating flow and rotating flow will have a serious impact on the metal tube float flowmeter. If the pulsating frequency coincides with the vortex street frequency, the electromagnetic flowmeter may cause resonance, destroy normal operation and equipment, and cause the vortex street signal to "lock", and the signal is fixed at a certain frequency. "Lock" is related to the pulsating amplitude, the shape of the vortex generator and the blockage ratio. The accuracy of the metal tube float flowmeter is roughly ± (0.5%~2%)R for liquids and ± (1%~2%)R for gases, and the repeatability is generally 0.2%~0.5%.

　　For vortex flow, if it is 1, it means pulse signal output, bus temperature transmitter; if it is 3, it means with 485 communication; if it is 4, it means battery power supply, without temperature and pressure compensation; if it is 5, it means integrated temperature and pressure compensation, with 4-20MA current output; if it is 6, it means integrated temperature and pressure compensation, battery power supply. When using metal tube float flowmeter for measurement, we must carefully select the model and pay attention to the details in the selection. Only by selecting the right model can the measurement accuracy of the flowmeter be guaranteed.