A bridge-type dual-core qcm sensor detection system and method thereof

Abstract

The invention relates to a bridge type double core QCM (Quartz Crystal Microbalance) sensor detection system, and a method thereof. The bridge type double core QCM sensor detection system includes a signal driving module, a QCM input grade module, a signal processing module, a high speed analog-to-digital conversion ADC module, an FPGA module, a serial port communication module and an upper layer PC module, wherein the QCM input grade module utilizes a structural form of a bridge circuit and double core QCM; for the signal driving module, a DDS signal generator is controlled by the FPGA module to generate a cosine signal to drive a QCM sensor; the signal processing module is used for extracting QCM weak useful signals from the background noise according to the related principle, and the QCM weak useful signals are sent to the FPGA module after acquisition and conversion through the high speed analog-to-digital conversion ADC module; and the FPGA module performs real-time data processing and sends the final data to the PC to analyze and display the result. The bridge type double core QCM sensor detection system, and the method thereof utilize the steady state response method, and can obtain the information through one time of measurement, such as impedance half-peak width and frequency change, and has high measuring accuracy.

Description

technical field [0001] The invention belongs to the field of sensor detection, and in particular relates to a bridge-type dual-core QCM sensor detection system and a method thereof. Background technique [0002] Quartz crystal microbalance (Quartz Crystal Microbalance, QCM) is a sensor measurement technology developed in the 1960s. It is a branch of the field of material detection. A resonant sensor with extremely high sensitivity is formed, and the accuracy can reach the nanogram level when detecting the mass. [0003] The measurement principle of QCM is based on the piezoelectric effect. When the crystal is applied with an alternating electric field, it will oscillate. When the oscillation frequency is consistent with the natural frequency of the quartz crystal, resonance will occur. At this time, if the single-sided electrode of the QCM is in contact with the substance to be measured, the resonance frequency of the QCM will change, and there is a linear relationship betw...

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Problems solved by technology

[0006] Although QCM measurement technology has unique advantages and good prospects in many engineering fields, its commercial application still faces many problems, one of which is that it is greatly affected by the environment, especially temperature, making its performance unable to meet high-precision measurement requirements

Most of the existing QCM detection systems currently use a monolithic crystal sensor structure. However, a single measurement of a monolithic sensor structure can only cover one detection substance, or two measurements are required to fully and accurately describe the detection substance. inconvenient

In addition, when QCM is used in the liquid phase, its oscillation damping is large, the output signal is very weak, and the useful signal is often submerged in the background noise. Previously insignificant interference factors will affect the measurement accuracy of QCM. If the traditional oscillation circuit method is used, Not only the amount of measured information is small, but also the vibration stop phenomenon will occur in the large damping solution

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