Capacitive radio-frequency admittance level transmitter and operating method thereof

Abstract

The invention relates to a capacitive radio-frequency admittance level transmitter and an operating method thereof. A high-frequency sinusoidal excitation signal output by a high-frequency driver is loaded into a capacitance sensor; through analyzing the sizes of an AC (alternating current) component and a DC (direct current) component of a response signal of the capacitance sensor, the impedance and condensance of the capacitance sensor are calculated through the operation of an MCU (micro-programmed control unit); and the condensance of an attachment is obtained through backstepping according to a conclusion that in a radio-frequency admittance theory, a real part and an imaginary part which are subjected to equivalent admittance by the attachment are numerically equal, so that the real capacitance is equal to a value obtained by subtracting the attachment capacitance from the measured capacitance, thereby eliminating the measurement errors of the attachment caused by that a measured medium is adhered to an electrode, solving the difficult problem that the measurement errors of viscous measured materials or solid powdered measured materials are large, improving the measurement precision, and guaranteeing the measurement stability.

Description

technical field [0001] The invention relates to a detection technology, in particular to a capacitive radio frequency admittance level transmitter. Background technique [0002] Level refers to the position of the interface between liquids, powdery solids, and gases in storage containers or industrial production equipment, or it can be the interface position between two incompatible liquids due to unequal densities. According to the specific use, it is divided into liquid level, material level, boundary level sensor or transmitter. Level is one of the main parameters involved in the control process. Level is not only a parameter for material consumption or output measurement, but also an important parameter to ensure continuous production and equipment safety. Especially in modern industry, the production scale is large, the speed is high, and there are often high temperature, high pressure, strong corrosive or flammable and explosive materials, which is very important for...

AI Technical Summary

Problems solved by technology

[0006] The present invention aims at the problem that the existing capacitive level transmitter has large measurement errors and instability when the measured material is viscous or solid powder, and proposes a capacitive radio frequency admittance level transmitter and its working method, simultaneous detection of capacitance and resistance can eliminate the measurement error caused by the adhesion of the measured medium to the electrode, and achieve accurate measurement results

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