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1. Understand the process parameters: (1) Know the name of the liquid to be measured (provided by the user). (2) Know the maximum, normal, and minimum flow rates of the liquid to be measured (provided by the user). (3) Know the diameter of the process pipeline (provided by the user). (4) Know the temperature of the medium (provided by the user). (5) Know the pressure of the medium (provided by the user). (6) Know the conductivity of the fluid to be measured (provided by the user). (7) Know whether there is negative pressure present (provided by the user). 2. Preliminary selection: (1) Based on the name and properties of the medium to be measured, determine whether to use an electromagnetic flowmeter (determined by the sales representative). Note: Electromagnetic flowmeters can only measure the flow rate of conductive liquids; gases, oils, and most organic liquids do not fall under the category of conductive liquids. (2) Based on the properties of the medium, determine the electrode material； The company generally provides four types of electrodes: stainless steel, Hastelloy, titanium, and tantalum. The choice of electrode should be determined by referring to the relevant data sheets based on the properties of the medium. (2) Depending on the temperature of the medium, it will be decided whether to use a rubber or PTFE lining (this is determined by the sales representative). Note: Rubber can withstand temperatures up to 80°C only ； Tetrafluoride can withstand temperatures of 150°C, and temporarily up to 180°C ； For urban wastewater, a rubber lining and stainless steel electrodes can generally be used. (3) Determine the flange specifications for the gauge based on the pressure of the medium involved (as determined by the sales representative). Note: The flange specifications for electromagnetic valves are usually such that when the diameter ranges from DN10 to 250, the rated pressure of the flange is ≤1.6 Mpa ； When the diameter ranges from DN250 to 1000, the flange’s rated pressure is ≤1.0 Mpa ； When the actual pressure of the medium is higher than the corresponding range defined by pipe diameter and pressure, it constitutes a special order; however, the maximum pressure shall not exceed 6.4 Mpa. (4) Determine the conductivity of the medium. Note: (1) The conductivity of electromagnetic flowmeters must be at least 5 uS/cm. (2) The conductivity of tap water is in the range of several dozen to hundreds of uS/cm; generally, boiler soft water (deionized water) is conductive, while pure water (highly distilled water) is non-conductive. (3) Gases, oils, and most organic liquids have a conductivity far below 5 uS/cm, meaning they are non-conductive. 3. Understand user requirements: (1) Determine whether a combined local display or a separate remote display is required (to be specified by the user). Note: When a separate remote display is needed, the maximum distance should be considered; the maximum separation distance is 100 meters. (2) Identify if any additional functions are required (to be specified by the user). Note: 1. The electromagnetic flowmeter already comes equipped with functions for upper and lower flow limit alarms, as well as frequency and current output, so no special orders are necessary. 2. The sealing protection levels for the electromagnetic flowmeter’s housing are IP65 and IP68; choosing the IP68 version for use in submerged environments requires a special order. 3. If the electromagnetic flowmeter needs to be connected to a computer, an RS-485 communication port must be added, which also constitutes a special order. 4. Model selection: After following the above steps, the final model and specifications of the electromagnetic flowmeter can be determined.