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Today, we will introduce the working principles of Rosemount and sensors, providing a detailed explanation of Rosemount’s principles for mass flow measurement and density measurement, as well as the signal characteristics of transmitters and the features and applications of DSP digital signal processors. Rosemount is now used in many fields and is one of the most advanced flow measurement instruments in the world. It is reliable for measuring key products in certain companies, such as ethylene, propylene, and light hydrocarbons that serve as raw materials, with an accuracy of up to 1.7‰. This improves the accuracy of flow measurement of energy and materials, prevents unnecessary losses, and generates significant economic benefits. Principle of mass flow measurement The measurement system of a mass flow meter consists of a sensor and a transmitter for signal processing. The Rosemount mass flow meter is based on Newton’s second law: Force = Mass × Acceleration (F=ma). As shown in Figure 1, when a particle with mass m moves at velocity V within a pipe that rotates around axis P at an angular velocity ω, the particle experiences two types of acceleration and corresponding forces: (1) Normal acceleration, or centripetal acceleration αr, whose magnitude is equal to 2ωr, and it acts toward axis P; (2) Tangential acceleration αt, or Coriolis acceleration, whose value is equal to 2ωV, and its direction is perpendicular to αr. Due to the combined motion, a Coriolis force Fc=2ωVm acts on the particle in the αt direction, while the pipe exerts an opposite force -Fc=-2ωVm on the particle. When a fluid with density ρ flows at a constant velocity V through a rotating pipe, any segment of the pipe of length Δx is subjected to a tangential Coriolis force ΔFc: ΔFc=2ωVρAΔx (1) Where A is the cross-sectional area of the pipe. Since the relationship mq=ρVA holds, it follows that ΔFc = 2ωqmΔx (2). Therefore, by directly or indirectly measuring the Coriolis force of the fluid flowing in the rotating tube, the mass flow rate can be determined.