Design And Research Of A Wireless Electronic Nose Based On GPRS

As a novelty bionic technology, the electronic nose has attracted attention in detection of food and agricultural byproducts. Literatures have been reported in the applications of tea, vegetables, fruits, meat, dairy, oil, wine, beverage and so on, showing a wonderful application effect and prospect in food and agricultural byproducts detection by using the electronic nose.However, an electronic nose in the conventional sense usually consists of one highly integrated sensor array module, one highly complex signal processing module and one powerful pattern recognition module, which may be energy-intensive and bulk. Besides, each module is wired with each other, although the application field of the electronic nose has extensive universality, detection applications in the on-site or mobile scenes will be rejected because of its large power consumption, bulky size, wiring system and other shortcomings. In addition, the necessity of being manually operated also limit the electronic nose using in certain situations, such as the toxic and hazardous scenes.Facing with those shortcomings of the traditional electronic nose above-mentioned, this study aims at combining the electronic nose technology with the modern wireless technology, to develop an energy-efficient, portable and remote monitoring wireless electronic nose system, which can overcome the shortcomings of the traditional electronic nose and expand the application field.The main contents of this study are as follow:1) The hardware of the wireless electronic nose(WEN) based on GPRS for applications in the "on-the-go" scene was designed. It consisted of 6 modules which were a sensor-array with 8 MOS sensors, a signal processing module, a master controlling module, a GPRS module, a gas sampling and delivering system and a remote monitoring system on the server.2) A C51 program for data acquisition and operation performing was programmed in microprocessor module which act as a lower system, while a Visual Basic program and its corresponding database program for remote monitoring and controlling was programmed in remote monitoring terminal on the PC3) After the communication performance of the GPRS module been tested, the present WEN was used to take an application aimed at fresh mangos. Mangoes with different ripening treatments and different storages were detected, thanks to a variety of data analysis and pattern recognition techniques (PCA, CDA, regression analysis, LDA-SVM, etc.), models qualitatively distinguish mangos with different ripening treatments and storages were established. On this basis, several physical, chemical and sensory indicators of the mangos were further obtained, helping to establish a quantitative model between the electronic nose data and the indicators.