Comparison of advantages and disadvantages between electromagnetic flowmeter and ultrasonic flowmeter

NegotiableUpdate on 03/21

Model

Nature of the Manufacturer: Producers

Product Category

Place of Origin

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Overview

Electromagnetic Flowmeter

Product Details

Electromagnetic Flowmeter

1. Advantages

① Electromagnetic flow meters can be used to measure industrial conductive liquids or slurries;

② No pressure loss;

③ The measurement scale is large, and the diameter of the electromagnetic flow transmitter ranges from 4mm to 2.6m.

④ The electromagnetic flowmeter measures the volumetric flow rate of the measured fluid in the operating state, and the measurement principle does not involve the influence of fluid temperature, pressure, density, and viscosity.

2. Disadvantages

① The use of electromagnetic flow meters has certain limitations. They can only measure the liquid flow rate of conductive media and cannot measure the flow rate of non-conductive media, such as heating water with better gas and water treatment. In addition, the temperature resistance of the lining needs to be considered under high temperature conditions.

② Electromagnetic flowmeter is a volumetric flow rate determined by measuring the velocity of conductive liquid during operation. According to the measurement requirements, for liquid media, the mass flow rate should be measured, and measuring the medium flow rate 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 fluid density and only provides volumetric flow rate at room temperature, it is not appropriate.

③ Scaling or wear of the water supply pipeline can change the inner diameter scale, affecting the original flow rate value and causing measurement errors. If the outer diameter of the 100mm caliber changes by 1mm, it will result in an additional error of about 2%.

④ The measurement signal of the transmitter is a very small millivolt potential signal. In addition to the flow signal, there are also some signals unrelated to flow, such as phase voltage, orthogonal voltage, and common mode voltage. In order to accurately measure flow, it is necessary to eliminate various interference signals and effectively amplify flow signals. The performance of the flow converter should be improved, preferably using a microprocessor type converter to control the excitation voltage. The excitation method and frequency should be selected according to the properties of the measured fluid, which can eliminate in-phase and quadrature disturbances. But the improved appearance structure is complex and costly.

电磁流量计与超声波流量计的优缺点比较

ultrasonic flowmeter

1. Advantages

① Ultrasonic flowmeter is a non-contact surface measurement device that can be used to measure fluid flow rates and large pipe diameters that are difficult to touch or investigate. It will not change the flow state of the fluid, will not cause pressure loss, and is easy to install.

② Capable of measuring the flow rate of highly corrosive and non-conductive media.

③ The measuring scale of ultrasonic flowmeter is wide, with a measuring diameter ranging from 2cm to 5m.

④ Ultrasonic flow meters can measure the flow rates of various liquids and wastewater.

⑤ The volumetric flow rate measured by an ultrasonic flowmeter is not affected by thermal properties such as temperature, pressure, viscosity, and density of the fluid being measured. It can be made in both fixed and portable forms.

2. Disadvantages

① The temperature measurement scale of ultrasonic flow meters is not high, generally only capable of measuring fluids with temperatures below 200 ℃.

② Poor anti-interference ability. Easy to be disturbed by ultrasonic noise from bubbles, scaling, pumps, and other sources, which can affect measurement accuracy.

③ The straight pipe section has strict requirements, with the first 20D and the last 5D Otherwise, the discreteness is poor and the measurement accuracy is poor.

④ The uncertainty of the device can cause significant errors in flow measurement.

⑤ Due to scaling, measuring pipelines can seriously affect measurement accuracy, resulting in significant measurement errors, and even in severe cases, there may be no visible flow on the surface.

⑥ The reliability and accuracy level are not high (generally around 1.5-2.5 levels), and the repeatability is poor. Ultrasonic flowmeter determines flow rate by measuring fluid velocity and multiplying it by the cross-sectional area inside the pipeline. However, this flowmeter cannot directly measure the inner diameter and pipe roundness, and can only estimate the cross-sectional area based on the outer diameter and wall thickness according to the standard circle. The resulting uncertainty has exceeded 1%, thus limiting the accuracy.

So the above is the answer provided by the editor for everyoneAdvantages and disadvantages of electromagnetic flowmeter and ultrasonic flowmeterHope it can help everyone. If you want to learn more knowledge, pay more attention to Huayun Instrument!