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1. Since the output signal of the sensor in an electromagnetic flowmeter is very small, usually only a few millivolts. To improve the immunity of instruments to interference, the zero potential in the input circuit must be grounded, with the earth’s potential taken as the zero potential; this is a sufficient condition for grounding sensors. Poor grounding or the absence of a ground wire can lead to external interference signals, causing errors in sampling by the AD converter of the electromagnetic flowmeter. The error manifestations include empty readings, a signal value of zero, or negative signal values. 2. The ground point of the sensor’s output signal must be electrically connected to the medium being measured; this is a necessary condition for the operation of an electromagnetic flowmeter. If this condition is not met, the electromagnetic flowmeter cannot function properly, as determined by the sensor’s signal circuit. When the fluid cuts through the magnetic field lines to generate a flow signal, the fluid itself serves as the zero potential; a positive potential is generated at one electrode, while a negative potential is generated at the other electrode, with these potentials alternating continuously. Therefore, the midpoint of the converter’s input side (the shield of the signal cable) must be at the same zero potential as the fluid and conductive, so as to form a symmetric input circuit. The midpoint of the converter’s input side is electrically connected to the fluid under test through the ground point of the sensor’s output signal. 3. Regarding the issue of connection to the ground using the earth potential as the reference potential, since ordinary metal pipes are all connected to the ground and the flowing medium is electrically connected to the ground through these metal pipes, this requirement is generally met. In summary, an electromagnetic flowmeter does not necessarily require a separate grounding device, especially for those with small diameters; however, having a separate grounding device contributes to the reliable operation of the instrument. In other words, a correct understanding of the grounding issue for electromagnetic flowmeters is necessary; it should be given attention, but without excessive emphasis in a blind manner. I. Overview of Electromagnetic Flowmeter Selection: The measurement principle of the HD-LDE electromagnetic flowmeter is Faraday’s law of electromagnetic induction. The main components of the sensor are: the measurement tube, electrodes, excitation coil, core, and yoke housing. It is mainly used to measure the volumetric flow rate of conductive liquids and slurries in closed pipelines. Including highly corrosive liquids such as acids, bases, and salts. This product is widely used in industries such as petroleum, chemicals, metallurgy, textiles, food, pharmaceuticals, and papermaking, as well as in fields like environmental protection, municipal management, and water conservancy construction. The MS-LD series of electromagnetic flowmeters are fully intelligent electromagnetic flowmeters developed using the most advanced technologies available at home and abroad; their all-Chinese language electromagnetic converter core is equipped with a high-speed central processing unit. It features very fast calculation speed, high precision, and reliable measurement performance. The converter circuit design utilizes advanced international technologies; it features an input impedance of up to 1015 ohms, a common-mode rejection ratio of over 100 dB, and a suppression capability against external interference as well as 60Hz/50Hz interference of over 90 dB. This enables the measurement of flow rates in fluid media with very low conductivity. Its sensor utilizes non-uniform magnetic field technology and a special magnetic circuit structure, ensuring stable and reliable magnetic fields. This approach also significantly reduces the size of the device, thereby minimizing weight and enabling the flow meter to have a compact design. To ensure that customers can buy with confidence, use with ease, and receive satisfactory service is our company’s mission. II. Product features for selecting electromagnetic flowmeters: ▲ There are no moving parts or flow-blocking components inside the pipeline, resulting in almost no additional pressure loss during measurement. ▲ The measurement results are independent of physical parameters such as flow velocity distribution, fluid pressure, temperature, density, and viscosity. ▲ On-site, the range can be modified online according to the actual needs of the user. ▲ High-definition backlit LCD display, with a fully Chinese-language menu for easy operation; it is simple to use, straightforward to operate, and easy to learn. ▲ SMD devices are used, along with surface mounting (which ensures high circuit reliability). ▲ It uses a 16-bit embedded microprocessor, which offers fast processing speeds and high precision. It enables programming of low-frequency rectangular wave excitation, thereby improving the stability of flow measurement, and it has low power consumption. ▲ Fully digital processing provides strong interference resistance, reliable measurement, and high precision; the flow measurement range can reach 150:1. ▲ It features an ultra-low EMI switching power supply with a wide operating voltage range and excellent EMC resistance. ▲ It includes three accumulators that can display the positive cumulative value as well as the differential cumulative value; it also has a non-volatile clock that can record 16 power outage times. ▲ It offers digital communication signal outputs such as RS485, RS232, Hart, and Modbus. For more information, please visit the company’s official website at http://www.yb1518.com/. Please keep this link when reproducing the content! http://www.yb1518.com/UploadFiles/2012717174126829.jpg