1. Determine whether to use an electromagnetic flowmeter according to the name and properties of the measured medium.
Note: Electromagnetic flowmeters can only measure the flow of conductive liquids, while gases, oils and most organic liquids are not examples of general conductive liquids
2. Determine the electrode material according to the learned properties of the medium
Note: The company generally provides four kinds of electrodes, such as stainless steel, Hastelloy, titanium and tantalum. Which electrode should be selected should be checked according to the properties of the medium.
3. Determine whether to use rubber or PTFE lining according to the learned medium temperature
Note: The temperature resistance of rubber shall not exceed 80C;
Teflon temperature resistance 150C, instant 180C resistance;
Urban sewage can generally use rubber lining and stainless steel electrodes
4. According to the known medium pressure, select the flange specification of the meter body.
Note: The specification of electromagnetic flange is usually when the diameter is from DN10-250, the rated pressure of the flange is less than or equal to 1.6Mpa;
When the diameter is from DN250-1000, the flange rated pressure is less than or equal to 1.0Mpa;
When the actual pressure of the medium is higher than the corresponding range of the above pipe diameter-pressure, it is a special order, but the maximum pressure shall not exceed 6.4Mpa
5. Determine the conductivity of the medium
Note: (1) The conductivity of the electromagnetic flowmeter shall not be lower than 5uS/cm
(2) The conductivity of tap water is about tens to hundreds of uS/cm. Generally, boiler soft water (deionized water) is conductive, and pure water (highly distilled water) is not conductive.
(3) The electrical conductivity of gas, oil and most organic liquids is much lower than 5uS/cm, which is non-conductive.
