Electromagnetic excitation detection-based resonant tuning fork liquid density sensor

Abstract

An electromagnetic excitation detection-based resonant tuning fork liquid density sensor comprises a tuning fork, a fixed support body, a protection tube, two magnetic cylinders, two coils, two fixing members, and a temperature sensor. The protection tube is welded on the fixed support body. The magnetic cylinders and the coils are mounted on the fixed support body via the fixing members, for cooperative use, to constitute an exciter and a detector respectively. The exciter transfers the generated alternating force to the tuning fork via the fixed support body, so that the tuning fork generates simple harmonic vibration according to the natural frequency of the tuning fork, and the vibration signal is acquired by the detector to realize detection of the tuning fork vibration frequency. The vibration frequency of the tuning fork and liquid density are in monotonic function relationship, thus real-time online measurement of the liquid density can be realized. The temperature sensor is attached to the fixed support body to real-time detect the temperature of the measured liquid, so as to compensate change in the modulus of elasticity of the tuning fork. The sensor of the invention can realize high-precision online measurement of various liquid densities at different temperatures.

Description

technical field [0001] The invention relates to a resonant tuning fork liquid density sensor for electromagnetic excitation detection, which is a high-precision resonant quasi-digital sensor, belongs to the field of testing and measuring instruments, and is used for high-precision online measurement of liquid density. The resonant element is a tuning fork. Background technique [0002] Density is an important physical property of liquids. Measuring liquid density is one of the important means to achieve product quality control in many industries such as medicine, food, petrochemical and so on. Therefore, the measurement of liquid density is of great significance to enterprises. Traditional liquid density measurement methods, such as balance weighing method, density bottle method, float meter method, etc. These methods are mainly manual operation and manual reading. Therefore, it can only be used in discontinuous measurement occasions, and cannot convert physical quantities ...

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Problems solved by technology

Among them, the vibrating string method has a complex structure, is easily affected by the mechanical vibration of the environment and liquid flow, and has low precision; the vibrating tube method is more commonly used, but its flow rate is small, the mode shape is asymmetrical, and the vibration frequency is not stable enough; the vibrating membrane method The work is not easy to be stable and the reliability is poor; the vibrating cylinder method has high requirements on the manufacturing process, the uneven wall thickness of the vibrating cylinder will easily make the mode shape asymmetrical, the vibration frequency is unstable, and the viscosity of the liquid will affect the frequency of the vibrating cylinder

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