What is the working principle of a mass flow meter?

『Principle of use of mass flowmeter』Related information(clamp on meter|electromagnetic meter|venturi meterrotameter|orifice meter|ultrasonic flow meter|mass flow meter|coriolis mass flow meter|coriolis flow meter|magnetic flow meter|magmeter flow meter|magflow flow meter|mag meter flow meter|electromagnetic flow meter|vortex flow meter|turbine flow meter|thermal mass flow meter|thermal flow meter|rotameter flow meter)

1. Working principle of mass flowmeter. Rosemount mass flowmeter, as one of the most advanced flow measurement instruments in the world today, is widely used in petrochemical and other fields. Its working principle is based on Newtons second law: force=mass x acceleration (F=ma). When a particle with a mass of m moves at a velocity V in a pipeline rotating at an angular velocity ω about the P axis, the particle experiences two components of acceleration and force:

(1) normal acceleration, i.e. centripetal acceleration α r, with a magnitude equal to 2 ω r, facing the P axis;

(2) Tangential angular velocity α t, also known as Coriolis acceleration, has a value equal to 2 ω V and is perpendicular to α r. Due to composite motion, a Coriolis force Fc=2 ω Vm acts on the particle in the α t direction, and the pipeline exerts a reverse force Fc=-2 ω Vm on the particle. When a fluid with a density of ρ flows at a constant velocity V in a rotating pipeline, any section of the pipeline with a length Δ x will experience a tangential Coriolis force Δ Fc: Δ Fc=2 ω V ρ A Δ x, where A represents the cross-sectional area of the pipeline. Therefore, directly or indirectly measuring the Coriolis force of the fluid flowing in a rotating tube can determine the mass flow rate. The sensor of the mass flowmeter is a U-shaped flow tube. When there is no fluid flowing through the trapped limb staring flow tube, the flow tube is driven by an electromagnetic drive coil installed at the end of the flow tube, with an amplitude of less than 1mm and a frequency of about 80Hz. When the fluid flows into the flow tube, it is forced to accept the vertical movement of the flow tube. During the half cycle of upward vibration of the flow tube

, the fluid resists the upward movement of the tube and exerts a downward force on the flow tube; On the contrary, the fluid flowing out of the flow tube exerts an upward force on the flow tube to resist its downward movement and reduce its vertical momentum. This leads to distortion of the flow tube. During the other half of the vibration cycle, the flow tube vibrates downwards in the opposite direction, and this distortion phenomenon is called Coriolis force. According to Newtons second law, the amount of distortion in a flow tube is directly proportional to the mass flow rate passing through it. Electromagnetic signal detectors installed on both sides of the flow tube are used to detect the vibration of the flow tube. When no fluid flows through the flow tube, the flow tube does not twist, and the detection signals of the electromagnetic signal detectors on both sides are in phase; When fluid flows through the flow tube, the flow tube is twisted, resulting in a phase difference between the two detection signals. The magnitude of this phase difference is directly proportional to the mass flow rate flowing through the flow tube. The signal characteristics of Rosemounts transmitters are modular and equipped with microprocessor functionality, combined with ASICS digital technology, and can choose digital communication protocols. It can be connected to sensors to obtain high-precision mass flow, density, temperature, and volume flow signals, and convert the obtained signals into analog, frequency, and other output signals. It can also be configured, checked, and communicated using the 275 HART protocol communication controller or AMS, Prolink software. The influence of measurement environment

1. The influence of flui

『SILVER Official Website SERVICE』