Instruction Manual for Electromagnetic Flowmeter

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Electromagnetic flowmeters are used in many applications, and today the editor will introduce what the specific instruction manual for electromagnetic flowmeters looks like. 　　Its working principle is based on Faraday’s law of electromagnetic induction. The conductive medium inside the measuring tube functions as the conductive metal rod in Faraday’s experiment, with two electromagnetic coils at the upper and lower ends generating a constant magnetic field. An induced voltage is generated when a conductive medium flows through it. The two electrodes inside the pipe measure the induced voltage generated. The measuring pipeline achieves electromagnetic isolation from the fluid and the measuring electrodes through a non-conductive lining (rubber, Teflon, etc.), as shown in the figure. Advantages and unique selling points of electromagnetic flowmeters:
1. The coil, the most important component of the sensor, is designed optimally, and rigorous actual-flow tests are conducted to ensure high measurement accuracy.
2. The signal electrodes are thoroughly shielded from static electricity, preventing interference from the coil and ensuring accurate measurements at low flow rates.
3. The coil is isolated from the outside environment, maintaining its insulation properties over time and thus ensuring long-term measurement accuracy.
4. All welding processes for the sensor use TIG welding; although this increases costs, it ensures the reliability of the welds (as welding is the most critical manufacturing process for sensors). In particular, the final welding step after installing the coil is carried out using TIG welding to prevent damage to the coil.
5. A grounding electrode structure is used to create a balanced electrode plane, ensuring that the entire measurement process takes place within this plane. This helps to eliminate electrical noise interference and provides accurate results.
6. Electromagnetic flowmeters use custom double-layer shielded cables.
7. Programmable low-frequency rectangular wave excitation improves the stability of flow measurement while reducing power consumption.
8. For measuring special media such as slurries, high-frequency excitation is used to eliminate noise interference.
9. A 16-bit embedded microprocessor is used, offering fast processing speeds and high precision.
10. Fully digital processing ensures strong resistance to interference, reliable measurements, and high accuracy.
11. An ultra-low EMI switching power supply allows operation over a wide range of voltage levels, with excellent EMC performance.
12. All functions are implemented on a single circuit board, using SMD components and surface-mount technology, which enhances circuit reliability.
13. A high-resolution backlit Chinese LCD display shows cumulative flow, instantaneous flow, flow rate, flow percentage, etc.
14. Menu-based operation makes the device easy to use, simple to operate, and straightforward to understand.
15. A bidirectional measurement system is available, with three accumulators that can display forward cumulative values, reverse cumulative values, and the difference between them.
16. Self-check and self-diagnosis functions are available, with results displayed on the screen.
17. A unique lightning protection design is incorporated.

Installation considerations for electromagnetic flowmeters:
1. The protection rating of the electromagnetic flowmeter. In accordance with the national standard GB4208-1984, which is similar to the International Electrotechnical Commission IEC standard (IEC529-7B), the protection rating for enclosures is as follows: IP65 denotes a level of protection against water spray; it allows water to be sprayed at the instrument from any direction, with a spraying pressure of 30 Kpa. The water output is 0.75 m3/h, and the distance between the water spray nozzle and the instrument is 3 m; IP67 rating indicates protection against water immersion, meaning the instrument can be completely submerged in water, with the highest point being at least 150 cm below the water surface for a duration of at least 30 minutes. IP68 means it is submersible and can operate underwater for extended periods. In accordance with the above regulations, instruments that are prone to being flooded and installed underground should be of IP68 rating, while those installed on the ground should preferably be of IP65 rating. 　　2. Select grounding based on the insulation of the pipes connecting the instruments. 　　3. Select the nominal pressure of the electromagnetic flowmeter based on the maximum pressure of the medium being measured. For flow measurement at medium pressures of 10 MPa, 16 MPa, 25 MPa, and 32 MPa, high-pressure electromagnetic flowmeters should be used. Its maximum diameter is 100mm. 　　4. There must be a straight pipe section of at least 5*D length in front of the electromagnetic flowmeter (where D is the inner diameter of the flowmeter), and a straight pipe section of at least 3*D length behind it; the flow direction of the fluid should be consistent with the direction indicated by the arrow on the flowmeter. A vacuum inside the pipeline can damage the lining of the flowmeter, so this aspect requires special attention. There should be no strong electromagnetic fields near the electromagnetic flowmeter. Sufficient space should be available around the flowmeter for installation and maintenance purposes. If the measurement pipeline vibrates, fixed supports should be installed on both sides of the flowmeter. When measuring mixed liquids composed of different substances, the distance between the mixing point and the flowmeter should be at least 30×D (where D is the inner diameter of the flowmeter). To facilitate future cleaning and maintenance of the flowmeter, a bypass pipeline should be installed. For more information, please visit the company’s official website at http://www.yb1518.com/. Please retain this link when reproducing the content!