Research For Detecting Oscillation Frequency Of QCM

Piezoelectric quartz crystal sensor is a response to a kind of broad spectrum, high sensitivity,and simple structure,low-cost detection device,and in particular its quality as a type of gas sensor is widely used.With the success in liquid oscillation, piezoelectric quartz crystal sensor has been involved in the application analytical chemistry,surface chemistry,biochemistry and environmental monitoring side and many other fields.Quartz crystal microbalance(QCM) gas sensor,with sensitive quartz crystal surface film as the sensitive element,AT-cut quartz crystal as transducer components by use of a quartz crystal frequency of the quality of relations, change quality,concentration signals into output frequency signal,thus achieve quality,concentration detection.This paper studies the direction of QCM design optimization,with the main focus of the resonator element on QCM vibration coupling issues.The study analyzes the vibration coupling with method of quartz resonator equivalent circuit and summes up the resonator element vibration coupling of the equivalent circuit,which provides academic basis for QCM further analysis and design work.QCM sensor signal detection mainly concentrates on a relatively small changes in the frequency of testing with the development of quality paper micro-sensor detection as the purpose,according to the characteristics of QCM sensor,the study designs a reasonable start-up,plastic,and difference frequency processing circuit, and completes quartz microbalance(QCM) theoretical ideas and initially completes microbalance structures,and analytzes(concentration) signals by use of poor-quality treatment.Based on the phase equilibrium conditions of crystal oscillator circuit,it analyzes the liquid crystal oscillator circuit frequency stability of the impact of QCM and demarcates QCM,respectively validate with experiments the impact of system in which the solution density,temperature,viscosity,conductivity,angle on frequency.Which makes QCM as a new detection device plays more and more important role in modern analyse instrument and provides foundation for research of high capability and high sensitivity QCM.