A Computer Controlled Measurement System to Characterize Quartz

A Computer Controlled Measurement System to Characterize Quartz Crystal Oscillator Gas Sensors Hazem Zanoun Electrical Engineering Department 6 MHz Quartz Crystal Oscillator Sensor High Performance Thin Film Thickness/Rate Deposition Monitor + Oscillator Using RS 232 communications , the Lab. VIEW software and lab PC allows quick and simple results to be obtained from the film A computer controlled measurement system is being developed to measure response of Quartz Crystal Oscillator sensors to gas concentration. The quartz crystal senses the amount of the gas absorbed by a thin film of material coated on its surface by changing its resonant frequency. The thin film coating has a specific selectivity for the gas to being detected. The system uses Lab. View as the platform for interfacing, communication, data acquisition and control between a personal computer and the measurement setup via GPIB bus and serial ports. In the system a closed air circulation is used with the gas to be sensed mixed into the system via computer controlled mass flow controllers. The Lab. View program written controls the timing and the amount of the gas injection. After each injection the program triggers all measurement instruments and gathers data to quantify and generate plots of sensor response vs. injected gas concentration. This work is being developed under the guidance of Dr. M. G. Guvench, University of Southern Maine professor of Electrical Engineering. The Frequency of The Crystal is Obtained through an Oscilloscope A Third Party Lab. View Environment Is being Developed to Obtain The Frequency Directly From The Oscillator For verifying The Data Obtained By The Main Software