Flow measurement is widely applied across various fields, including industrial and agricultural production, national defense, scientific research, foreign trade, and daily life. In the petroleum industry-spanning everything from extraction, transportation, and refining to trade and sales-flow measurement permeates the entire process. No single stage can function without it; otherwise, the normal production and commercial operations of the petroleum industry could not be guaranteed. In the chemical industry, inaccurate flow measurement can lead to imbalances in chemical component ratios, compromising product quality and, in severe cases, resulting in production safety accidents. In the power generation industry, the measurement and regulation of flow rates for media such as liquids, gases, and steam play a pivotal role. The accuracy of flow measurement holds significant economic importance in ensuring that power plants operate at optimal parameters; furthermore, with the advent of high-temperature, high-pressure, and large-capacity generating units, flow measurement has become a critical element in guaranteeing the safe operation of power plants. For instance, a sudden interruption or reduction in the instantaneous feedwater flow to a large-capacity boiler could trigger severe accidents, such as boiler dry-outs or pipe ruptures. Consequently, flow measurement devices are required not only to provide accurate readings but also to issue timely alarm signals. In the steel industry, measuring the flow rates of circulating water and oxygen (or air) during the steelmaking process constitutes one of the key parameters for ensuring product quality. Flow measurement is likewise indispensable in sectors such as light industry, food processing, and textiles.
Among the most widely utilized transducers are the clamp-on (external) and insertion types. While single-channel ultrasonic flowmeters are characterized by their simple structure and ease of use, they exhibit poor adaptability to variations in flow regime distribution. However, the leaps forward in microelectronics and computer technology have profoundly accelerated the evolution and upgrading of instrumentation, leading to the emergence of new types of flowmeters in rapid succession. To date, it is estimated that hundreds of different flowmeter models have been introduced to the market, offering the potential to resolve many of the intractable challenges encountered in field applications. my country began its work on modern flow measurement technology relatively late. [The system includes] a component positioned at the upstream end of the measurement flow channel (6)-relative to apertures 11 and 12-designed to minimize the inflow of the fluid being measured into said apertures; a measurement and control unit (19), tasked with measuring the propagation time of ultrasonic waves between ultrasonic transducers 8 and 9; and a calculation unit (20), which computes the flow rate based on the signals received from the measurement and control unit (19). Flowmeters should, as far as possible, be kept away from ferromagnetic objects and equipment generating strong electromagnetic fields (such as large motors or transformers) to prevent external magnetic fields from interfering with the sensor's operating magnetic field and the flow signal. This applies specifically to the signal and excitation lines connecting the sensor and the converter. However, analyses of components damaged by lightning-induced faults indicate that the inductive high voltages and surge currents responsible for such failures are predominantly introduced via the power supply lines within the control room; the other two potential pathways are far less common sources of failure. Since electromagnetic flowmeters are far more frequently used to measure fluids containing suspended solids or contaminants than other types of flow instrumentation, the probability of faults arising from deposits accumulating on the inner walls is correspondingly higher. This risk is particularly pronounced if the electrical conductivity of the accumulated layer is similar to that of the fluid being measured. During the commissioning phase, common faults are typically attributable to improper installation.