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Setting of the accuracy grade for electromagnetic flowmeters The performance levels of the models available on the market vary greatly; some have high accuracy and numerous functions, while others have lower accuracy and simpler functions. Instruments with high precision have a basic deviation of (±0.5%～±1%) R, while those with lower precision have a deviation of (±1.5%～±2.5%) FS; the price of the former is 1 to 2 times that of the latter. Vortex flow meters are also known as vortex meter or Karman vortex flow meter. These products are carefully designed by integrating advanced technologies from developed countries and drawing on years of experience in research and production; they feature intelligence, standardization, serialization, versatility, and the use of standardized molds in manufacturing, all of which ensure high aesthetic quality. The electromagnetic flowmeter is a new type of flow measurement instrument that developed rapidly in the 1950s and 1960s along with the advancement of electronic technology. An electromagnetic flowmeter is an inductive instrument manufactured based on Faraday’s law of electromagnetic induction, used to measure the volumetric flow rate of conductive media within a pipe. Therefore, in applications where high measurement accuracy (precision) is not required (for example, in non-trade accounting where the purpose is merely control, or in situations where electromagnetic flowmeters only need to have high reliability and good repeatability), it is not economical to use instruments with high precision. Some models of meters claim to have higher accuracy, with a basic deviation of only (±0.2%–±0.3%) R, but they require strict installation conditions and reference parameters; for example, the ambient temperature should be between 20–22°C, and the lengths of the straight sections before and after the meter must be greater than 10D and 3D respectively (usually 5D and 2D). In addition, it is required that the flow sensor be integrated with the straight sections before and after it in a flow standard apparatus in order to carry out actual-flow calibration and reduce the influence of any interferences. Therefore, when comparing different model options, one should not focus solely on high performance indicators; for vortex flowmeters, it is necessary to read the manufacturer’s catalogs or manuals in detail in order to conduct a comprehensive analysis. The functions of EMFs in the market also vary greatly; some simple ones are designed only to measure one-way flow, outputting analog signals (definition: a virtual representation of real objects or processes) to drive subsequent instruments ； The multi-functional meter has functions such as measuring two-way flow, range switching, upper and lower flow limit alarms, empty pipe and power outage alarms, small signal rejection, flow display and total volume calculation, automatic verification and fault self-diagnosis, communication with a host computer, and motion configuration. Some models of electromagnetic flowmeters offer serial digital communication capabilities, with various communication interfaces and dedicated chips (also known as microcircuits, or ASICs) available. Turbine flowmeters can be connected to HART protocol systems, PROFIBUS, Modbus, CONFIG, FF field buses, and others. In addition to measuring the volumetric flow rate of ordinary conductive liquids, electromagnetic flowmeters can also be used to measure the volumetric flow rate of highly corrosive liquids such as strong acids and strong bases, as well as of homogeneous liquid-solid suspension fluids like sludge, pulp, and paper pulp. It is widely used for flow measurement in various industrial sectors such as petroleum, chemicals, metallurgy, light textiles, papermaking, environmental protection, and food processing, as well as in areas like municipal management, water conservancy construction, and river dredging. The prerequisite for using EMF is that the liquid being measured must be conductive and cannot fall below a threshold (i.e., the lower limit value). A conductivity below the threshold can cause measurement errors or even render the device unusable; whereas when the conductivity is above the threshold, measurements can still be taken even if there are changes, with little variation in the indicated error. The threshold for general-purpose EMFs ranges from 10-4 to (5×10-6) S/cm, depending on the model. In use, it also depends on the length of the signal line connecting the sensor and the converter, as well as the flow rate (in cubic meters per second), and their distributed capacitance. The manufacturer’s instructions usually specify the length of the signal line required for a given conductivity. For more information, please visit the company’s official website at http://www.yb1518.com/. Please retain this link when reproducing the content! http://www.yb1518.com/UploadFiles/2012717174126829.jpg