The Design Of Quartz Crystal Microbalance And It's Application In Lunar Dust Measurement

Quartz Crystal Microbalance(QCM)has high sensitivity and unique advantages in the measurement of tiny mass particles,especially in the lunar dust measurement.China has first used QCM on the Chang'e-3 lander for the lunar dust measurement.Based on the investigation of the lunar and cosmic dust detection in recent decades at home and abroad,this paper studies Chang'e-3 lunar dust measurement system,focused on the design of QCM and its application in the lunar dust measurement.Firstly,the paper introduces the application background of QCM,discussing the composition and design of the lunar dust measurement system.Because the quartz crystal frequency signal is easily interfered,it is necessary to adopt corresponding measures to stabilize its frequency in the hardware and software design of the lunar dust measurement system.Later,the design and application of QCM are emphatically studied.The specific work is following:(1)Based on the equivalent circuit analysis of quartz crystal resonator,a quartz crystal oscillator circuit suitable for the lunar dust measurement is designed.On the basis of studying the oscillation circuit and its equivalent circuit model,it is proved theoretically that the output frequency of the oscillating circuit depends only on the oscillating frequency of the quartz crystal resonator itself by analyzing and calculating the dynamic parameters of the circuit.The test results show that the output waveform of oscillation circuit is clear,the amplitude is stable,the frequency fluctuation is small,and the high-order harmonic components are few,which well meet the design and application requirements.(2)The test and calibration methods of QCM in the lunar dust measurement system are summarized.And its frequency drift curve is tested by corresponding experiments,giving such key parameters as its mass resolution,Weighing range,and frequency-mass conversion factor.(3)The in-orbit test of lunar dust measurement system is comprehensively introduced.Through the screening and processing of test data,the on-orbit test results are given,which proves the reasonable feasibility of QCM application in orbit.The research and test results show that QCM designed for the Chang'e-3 lunar dust measurement system in this paper operates reliably,which can meet the needs of lunar exploration project.And the test and calibration methods provide certain engineering reference for the micro-particles measurement in other fields at home.