The difference between ultrasonic flowmeter and electromagnetic flowmeter do you know

The difference between ultrasonic flowmeter and electromagnetic flowmeter do you know? A. The flow measurement accuracy of different ultrasonic flowmeters in media is almost unaffected by the parameters such as temperature, pressure, viscosity, density, etc. of the measured fluid, and it can be made non-contact and portable. Measuring instruments can solve the flow measurement problems of highly corrosive, non-conductive, radioactive and inflammable and explosive media that are difficult to measure for other types of instruments. Electromagnetic flowmeters cannot measure liquids with very low electrical conductivity, such as petroleum products and organic solvents. General-purpose electromagnetic flowmeters cannot measure high-temperature liquids due to liner material limitations. Electromagnetic flowmeters determine the volumetric flow under operating conditions by measuring the velocity of a conducting liquid. According to the measurement requirements, for the liquid medium, the mass flow should be measured. The measurement of the medium flow should involve the density of the fluid. Different fluid media have different densities and change with temperature. If the electromagnetic flowmeter converter does not consider the fluid density, it is not appropriate to give only the volumetric flow rate at room temperature. Second, the accuracy of different ultrasonic flow meter is to determine the volume flow by measuring the fluid velocity, the liquid should measure its mass flow, the instrument measurement of mass flow is obtained by multiplying the volume flow by the artificially set density, when the fluid temperature changes At that time, the density of the fluid changes, and artificially setting the density value does not guarantee the accuracy of the mass flow. The fluid density can only be measured at the same time as the fluid velocity is measured, so that the true mass flow value can be obtained through calculation. From the experience of ultrasonic flowmeters used in the domestic market, the main disadvantages currently existed were that the temperature range of the measurable fluid was limited by the degree of temperature resistance of the coupling material between the ultrasonic transducer and the transducer and the pipeline, and the other was insufficient. It is the incompleteness of the raw data of the measured sound propagation speed of the fluid under high temperature. At present, ultrasonic flowmeters in China can only be used to measure fluids below 200 °C. Ultrasonic flowmeters and electromagnetic flowmeters have different measurement media. Ultrasonic waves use sound waves at very low frequencies. Ultrasonic frequencies are from 20 kHz to 100 kHz. The radar uses 2.4 GHz-class electromagnetic waves. Ultrasonic waves are relatively restrictive and are easily exposed to other iron. The interference of system objects, in addition to low frequency, large attenuation, small measurement range, and narrow application surface, are commonly used in the flow measurement of large-caliber water pipelines and the measurement of liquid level in open channel flowmeters to convert them into flow. Also useful on solid bins. The electromagnetic frequency is high and the attenuation is small. If the waveguide is added, the measurement range can be very large, and it can be used on tanks. However, attention should be paid to the dielectric constant. A medium with a small dielectric constant cannot be measured or has a small measurement range. Since this kind of sensor must maintain a certain proportional relationship between the resistance in the pipeline and the impedance of the measurement circuit, there are certain difficulties in manufacturing. When the electrical conductivity of the measured medium is about 10 Ω/cm, it starts to have difficulty, and when the electrical conductivity is lower, the principle difficulty arises. When the conductivity is 10 Ω/cm, the “dividing line” between the conductive medium and the dielectric is reached, and the thermal noise level increases significantly with the increase of the internal resistance. High-precision ultrasonic flowmeters are multi-channel or pipe-segment type. Ultrasonic flowmeters of medium and small-diameter pipe segments are usually calibrated in real-time and have 0.5% accuracy. At present, the domestically-used monophonic ultrasonic flow has a nominal accuracy of 1%. However, in practical applications, the measurement accuracy exceeds the standard accuracy due to the fact that the inner diameter, wall thickness, and roundness of the field pipe cannot be accurately measured. To many degrees, for the measurement of the water supply industry, the actual measurement error of the ultrasonic flowmeter can be controlled within 3% even if the accuracy is high. Dongguan City, Lan Lan Electrical and Mechanical Equipment Co., Ltd. 15 years specializing in the production of proportional valve, electric two-way valve, fan coil thermostat, air conditioning billing and recycling water treatment. Warranty for two years, please call for details, service hotline ultrasonic flowmeter characteristics, electromagnetic flowmeter characteristics, flow meter characteristics, flow meter principle