Purchasing Considerations
Measurement Medium Characteristics
Conductivity: Electromagnetic flowmeters operate based on Faraday's law of electromagnetic induction, requiring the measured fluid to be conductive. Electromagnetic flowmeters are not suitable for non-conductive liquids (such as oil).
Corrosivity: It is important to select a flowmeter made of the appropriate material based on the corrosiveness of the liquid.
Temperature: The temperature of the measured fluid should be within the operating temperature range of the electromagnetic flowmeter. Excessively high temperatures may cause sensor performance degradation or damage.
Viscosity and Density: The viscosity and density of the fluid also affect the measurement accuracy and performance of the electromagnetic flowmeter.
Flow Range and Pipe Diameter
Select an appropriate flow range based on actual operating conditions to ensure that the flowmeter operates within its normal operating range to improve measurement accuracy. A flow range that is too large will result in inaccurate measurements, while a flow range that is too small may not meet actual requirements.
The flowmeter diameter should be the same as or slightly larger than the inner diameter of the pipe to avoid interference with fluid flow. Choosing a flowmeter specification that matches the pipe diameter ensures measurement accuracy.
Electrode Material
The choice of electrode material is crucial to the performance and service life of the electromagnetic flowmeter. Common electrode materials include platinum, gold, carbon, and stainless steel. Different electrode materials are suitable for different liquid media. For example, platinum electrodes are suitable for measuring high-temperature, highly corrosive liquids, while stainless steel electrodes are suitable for general water and sewage.
Sensor Types
Common sensor types include insertion and in-line types. Insertion sensors are suitable for larger pipes and are easy to install, but they may significantly interfere with fluid flow. In-line sensors are suitable for smaller pipes and high-precision measurements, providing more accurate results.
Environmental Conditions
Environmental factors such as temperature, humidity, and pressure may affect the flowmeter's measurement accuracy and stability. Therefore, when selecting an electromagnetic flowmeter, consider its adaptability to the operating environment to ensure its reliability in specific environments.
Budget and Brand
There are many brands and models of electromagnetic flowmeters on the market, with significant price differences. Users should choose a cost-effective product based on their budget and needs.
Selecting products from reputable brands generally offers better after-sales service and technical support, helping to ensure long-term stable operation and timely maintenance of the flowmeter.
Usage Precautions
Electromagnetic flowmeters should be used as far away from magnetic materials and devices with strong electromagnetic fields as possible to avoid magnetic interference.
When installing, choose a dry and ventilated location, ensure the temperature is within the electromagnetic flowmeter's operating range, and maintain a moderate humidity. Flowmeters should be installed in straight pipe sections, avoiding elbows, valves, and other locations to reduce turbulence and interference. The flowmeter's installation height and orientation must also comply with the manufacturer's specifications.
During use, cable connectors must be kept clean, dry, and protected from water and moisture. After each use, be sure to replace the flowmeter and cable head covers.
Electromagnetic flowmeter transmitters are not interchangeable and should be kept clean, stored indoors, and protected from water, moisture, vibration, and impact.