Piezoelectric quartz crystal sensor array with optimized oscillator circuit for analysis of organic vapors mixtures

An array of piezoelectric quartz crystal sensors (PQCs) has been prepared for analyzing organic vapor mixtures. The circuit of oscillators has been modified and optimized to circumvent the problems associated with mutual interference among different oscillators connecting to sensors in the array. Organic coating materials were clustered into four groups according to their polarity and compounds representing different groups were selected including silicone OV-101, silicone OV-17, silicone OV-275, span 85, and polyethylene glycol 1000. The sensor array constructed gives characteristic response patterns for different organic vapors such as methanol, 1,2-dichloroethane, benzene and cyclohexane. The feasibility of using the sensor array for analysis of binary and tertiary mixtures has been tested by using PLS and MLR data treatment algorithms.