Fault Analysis of Split Electromagnetic Flowmeter During Debugging Period

The split electromagnetic flowmeter is mainly used to measure the volume flow of conductive liquids and slurries in closed pipes. Including highly corrosive liquids such as acids, alkalis, and salts. The product is widely used in petroleum, chemical, metallurgical, textile, food, pharmaceutical, papermaking and other industries as well as environmental protection, municipal management, water conservancy construction and other fields. The
　　
　　split electromagnetic flowmeter has a fault with the initial commissioning, but once the fault is improved, it will generally not reappear under the same conditions. Common faults are mainly related to the installation and commissioning period, environmental interference, and the influence of fluid characteristics.
　　
　　(1) Pipeline system installation, etc.
　　
　　The common electromagnetic flow sensor installation position is incorrect. Common examples include flow sensors installed in natural gas pipeline networks that are easy to accumulate and retain high; flow sensors have no pressure, and the liquid is directly discharged into the atmosphere to form a complete measuring pipe; installed in the vertical line due to dirt, there may be air, and the installation of the flow meter is special because it is submerged underwater to ensure that there is no floating.
　　
　　(2) Environment
　　
　　: Main pipeline stray current interference, space electromagnetic wave interference, large motor magnetic field interference, and other pipeline stray current interference usually take good grounding protection to get satisfactory separate measurement, but in the case of pipes with strong stray current (such as electrolysis workshop assembly line), it cannot be overcome. Unique measures should be taken between the flow sensor and the pipeline edge. Electromagnetic wave-space signal cable introduction, usually single or multiple shielding protection, but also encountered shielding protection can not be overcome.
　　
　　(3) Fluid
　　
　　: Liquid containing tiny bubbles is usually evenly distributed, does not affect normal measurement, only the volume flow of liquid and gas combined; bubbles will increase the fluctuation of the output signal. If large bubbles cover the entire flow through the electrode surface, the electrode signal will be disconnected instantly, and the output signal will have a large fluctuation.
　　
　　Low-frequency (50/16hz-50/6 Hz) rectangular wave excitation split electromagnetic flowmeter will generate noise when measuring liquid containing more than a certain content of solid slurry, and the output signal will also have a certain degree of fluctuation.