Orifice plate flow meters combine a standard orifice plate with a multi-parameter differential pressure transmitter (or separate DP, temperature, and pressure transmitters) to form a high-rangeability differential pressure flow measurement system capable of measuring flow rates of gases, steam, liquids, and related media. Widely used in petroleum, chemical, metallurgical, power, heating, and water supply industries for process control and measurement, this type of throttling device—also known as a differential pressure flow meter—consists of a primary element (the orifice plate) and secondary instrumentation (differential pressure transmitter and flow indicator). Known for simple structure, easy maintenance, and stable performance, orifice plate flow meters are extensively applied across coal, chemical, transportation, construction, textiles, food, pharmaceuticals, agriculture, environmental protection, and daily life—playing a vital role in industrial and agricultural development, energy conservation, quality improvement, and enhanced economic and management efficiency. In process automation systems, flow meters serve two primary functions: as sensing elements for control systems and as totalizers for material quantity measurement.