Research On Design And Construction Of Experiment Platform For Electronic Nose

Electronic nose is an intelligent sensory-analyzing instrument which is principle similar to the biological sense of smell, and can characterize the overall features of odors' information quickly. With its characteristics of robustness, simplicity and safety, it is widely applied in the fields of food quality and safety inspection, biological, environmental studies. However, with the increasing widespread application of various types of electronic nose, such problems as deficient flexibility, weak configuration appear gradually, and other related problems. What is more, in some key technology areas, still few studies, such as the optimization of gas path and measurement chamber, sensor drift calibration, data testing repeatability and stability.In view of the requirements above, this research choose virtual instrument as a development platform, using its powerful, short development cycle, scalability and other advantages, building an electronic nose experiment platform. And then focus on the optimization of measurement chamber and gas path, anti-noise and filtering of signal, sensor drift calibration, and data testing repeatability and stability to improve the overall performance. Finally, choose white spirits, combine with pattern recognition algorithms, carry out the discrimination and identification experiments to verify the feasibility and reliability of the electronic nose system.The main research work and results are as follows.(1) In terms of the design and construction for this system. This study use the sensor arrays, the measurement chamber, gas delivery, data acquisition equipment to design the hardware of electronic system. And then in virtue of the virtual instrument technology, Lab VIEW, developed an electronic nose system testing software, which makes it possible to achieve the function of date acquisition, extract eigenvalue, database access and PCA.(2) In terms of the design for measurement chamber and gas delivery, According to the advantages and disadvantages of several common gas sampling method and the structure of measurement chamber, this research put forward the design of measurement chamber and the gas path in this electronic nose system, and checkout the gas flow with FLUENT fluid simulation software. Considering to different gas samples, this research added the Mass Flow Controller to control the gas flow rate.(3) In terms of the system optimization, Adopting hardware noise reduction and software filter to eliminate the signal noise. Using baseline calibration method to decrease sensor drift, ensured the stability of test data, extend the application scope of electronic nose.(4) In terms of system verification experiment. This study Use the PCA method to achieve the rapid discrimination of white spirits, and Using SIMCA method to identify different brands of white spirits. The results show that the electronic nose platform based on virtual instrument is feasible and reliable.In summary, this research using virtual machines as development environment, built an electronic nose experiment platform successfully, and achieved the desired results, has laid a good foundation for the follow-up experiments in expanding the application of electronic nose.