Flow measurement is extensively used in various fields, including industrial and agricultural production, scientific research, foreign trade, and people's daily lives. In the oil industry, flow measurement is integral throughout the entire process, from extraction, transportation, refining, and processing to trade and sales. It is indispensable in every step; without it, the normal production and trade of the oil industry cannot be guaranteed. In the chemical industry, inaccurate flow measurement can lead to imbalanced chemical composition ratios, compromising product quality and potentially causing production safety accidents. In the power industry, the measurement and regulation of fluid, gas, and steam flows are crucial. The accuracy of flow measurement is not only economically significant for ensuring power plants operate at optimal parameters but also, with the development of high-temperature, high-pressure, and large-capacity units, it has become a vital aspect of ensuring safe operation. For instance, a sudden interruption or reduction in the flow of feedwater to large-capacity boilers could result in severe dry-out or pipe explosion accidents. This necessitates that flow measurement devices not only provide accurate readings but also promptly emit alarm signals. In the steel industry, the measurement of circulating water and oxygen (or air) flow during steelmaking is a critical parameter for ensuring product quality. Flow measurement is also essential in light industry, food, textiles, and other sectors.

Popular transducers include the clamp-on and insertion types. The single-channel ultrasonic flow meter is simple in structure and easy to use, but it has poor adaptability to changes in flow distribution. The rapid advancement of microelectronics and computer technology has propelled the update and replacement of instruments, with new flow meters emerging like mushrooms after the rain. To date, it is said that hundreds of flow meters have been launched into the market, and many challenging issues in field use are expected to be resolved. Our country started the work on modern flow measurement technology relatively late, and the measurement control component 19, which is located at the upstream end of the measurement flow channel 6 and positioned relative to orifices 11 and 12, is used to reduce the inflow of the fluid being measured into orifices 11 and 12; the measurement control component 19, for measuring the propagation time of ultrasound between transducers 8 and 9; and the calculation component 20, for calculating the flow based on the signals from the measurement control component 19.

Flow meters should avoid magnetic materials and equipment with strong electromagnetic fields (such as large motors, large transformers, etc.) to prevent the magnetic field from affecting the sensor's working field and flow signal. The flow signal lines between the sensor and the converter, as well as the excitation lines. However, analysis of damaged components from lightning faults shows that most of the induced high voltage and surge currents causing the fault are introduced through the control room's power lines, with other pathways being less frequent. Since electromagnetic flow meters have a higher chance of measuring fluids containing suspended solids or contaminants than other flow meters, the probability of failure due to internal wall deposits is relatively high. If the conductivity of the deposit is similar to that of the liquid, common debugging period failures are often due to improper installation.