Electromagnetic FlowmeterAs a major category of flow meters, it is widely used because of its simple structure, and the fluid flowing through the flow meter will not experience pressure loss; Electromagnetic flow meters can measure the flow rate of domestic wastewater, industrial wastewater, and even liquid-solid two-phase flow. The main characteristics of electromagnetic flowmeter are: the measurement process is not easily affected by the density, temperature, and viscosity of the liquid; The speed measurement scale is relatively wide. Of courseElectromagnetic FlowmeterMeasurement is limited because electromagnetic flow meters can only measure conductive liquids and cannot measure gases and vapors. So what aspects should be considered when selecting an electromagnetic flowmeter?

1. Conductivity

The medium measured by electromagnetic flowmeter requires conductivity. The liquid conductivity needs to be greater than 5 μ s/cm.

2. Accuracy level

The accuracy of electromagnetic flow meters is high because liquid flow meters have a large measurement range. If the measurement range is large, the accuracy must be small, and the larger the range, the greater the error. Therefore, it is necessary to strictly control the accuracy. The accuracy of precision flow meters is in the range of 0.5-1, while the accuracy of conventional glass and metal rotors is in the range of 2.5. The difference is still quite significant. In terms of metering and billing, it is still necessary to choose high-precision electromagnetic flow meters.

3. Selection of flow velocity and caliber

The flow velocity requirement for electromagnetic flow meters is between 0.5-15m/s, and a reasonable flow velocity is generally between 1.5-3m/s. The flow rate is too fast, and if it contains particles, it may scratch the PTFE lining. There needs to be a reasonable selection of flow rate and caliber.

4. Selection of grounding ring and electrode materials

Due to the mismatch between the tested liquid and the electrode or grounding ring, which can cause defects, in addition to corrosion issues, there are also surface effects on the electrode, primarily including chemical reactions, polarization phenomena, and catalytic effects. The grounding ring also has these problems, but the impact level is smaller.

5. Contains solid phase in the body

If particles are assumed to be present in the liquid, the possible drawbacks include: covering up the accumulation layer on the surface of the electrode and fabric, fabric wear, and reduced cross-sectional area of the pipeline. Some relatively simple crystalline liquids may cause a layer of solid to hang on the inner wall when the fluid flows through the flowmeter. Since other types of flowmeters also have the same problem, a flowmeter with a very short measured pipeline and simple disassembly can be selected to stop protection after crystallization.