The electromagnetic flowmeter has a large measuring range, usually 20:1~50:1, and the optional flow range is wide; the diameter of the electromagnetic flowmeter is wider than other types of flowmeters, from a few millimeters to 3 meters; the positive and negative two-way flow can be measured. The pulsating flow rate can also be measured as long as the pulsation frequency is much lower than the excitation frequency; the meter output is linear in nature; it is easy to select the material type of the fluid contact member, and can be applied to corrosive fluids and the like. Since the electromagnetic flowmeter measures much more with suspended solids or dirt than other flow meters, the probability of failure of the inner wall adhesion layer is relatively high. If the electrical conductivity of the adhesion layer is close to the liquid conductivity, the instrument can output the signal normally, but only change the flow area to form a hidden fault of the measurement error; if it is a high conductivity adhesion layer, the electromotive force between the electrodes will be short-circuited; if it is an insulating adhesion layer The surface of the electrode is insulated to disconnect the measuring circuit. The latter two phenomena will make the meter inoperable.
Main features of vortex flowmeter
Measuring medium: nominal diameter of liquid, gas and steam: DN15-DN300 (non-standard products can be customized according to user requirements) Temperature range: -40°C~350°C Pressure specification: PN1.6Mpa; PN2.5Mpa; PN4.0Mpa, Higher pressure specifications can be customized to a specific range: normal range 1:10 Extended range 1:15 Pressure loss factor: Cd ≤ 2.6 System measurement accuracy: liquid, gas indication ± 1%, steam indication ± 1.5% plug-in flow The measured value is ±2.5% of the supply voltage: sensor +12VDC, +24VDC (optional) transmitter +24VDC.
On-site display type The meter comes with 3.6 lithium battery output signal: sensor pulse frequency signal 0.1~3000Hz low level ≤1V high level ≥6V.
Transmitter two-wire 4~20mADC current signal for vibration acceleration: Piezoelectric ≤0.2g Ambient temperature: -40°C~55°C (non-explosion-proof place) -20°C~55°C (explosion-proof place) Ambient humidity: Relative Humidity 5~85% signal remote transmission distance: ≤500m signal line interface: internal thread M20×1.5 explosion-proof grade: iaIICT2-T5 protection grade: ordinary IP65 submersible IP68 instrument material: converter shell is made of aluminum alloy, the body part is adopted 1Cr18Ni9Ti can also be made of special materials according to user requirements.
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.