Development Of Near-Infrared Spectrometer Control And Working State Monitoring Based On Android Platform

Near infrared spectroscopy technology has been applied in agriculture, food, chemical, petrochemical, pharmaceutical, tobacco and other fields. It is one of the most rapid development and eye-catching high-tech green analysis technology since 1990 s. With the improvement of the detection method and the extension of the application field, near infrared spectrometer is necessary to realize the function of self checking in order to achieve the stability of the spectrum and the convenient of the instrument maintenance.This research is conducted based on NIR-S410 near infrared spectrometer which is produced by Shanghai Lengguang Technology Co., Ltd. At first, the basic construction of the instrument is studied, and the feasibility of adding the temperature and humidity, temperature and voltage detection functions is evaluated on the original basis of the instrument. Meantime, light energy detection and wavelength energy correction fuctions are added. The whole framework of the application system software of near infrared spectrometer is determined. Using Eclipse development platform to achieve the design of system’s software, which is applied to the Android operating system mobile devices. The hardware design of self checking circuit including temperature and humidity, temperature and voltage is designed. Furthermore, the actual tests of temperature and humidity, temperature and voltage are conducted. According to spectra collected in the experiment, spectral processing is carried out. Lastly, the model call is verified. The main contents in this paper are as follows:Firstly, the influence of temperature and humidity on the near infrared spectrometer working state is studied. In the original machine, DHT11 digital sensor which is temperature and humidity detection accessory and DS18B20 digital sensor which is temperature detection accessory are added. At the same time, the WiFi module and the voltage detection module based on PCF8591 are increased. WiFi module is used to wireless communication with mobile devices.Secondly, the framework of near infrared spectroscopy(S410) application system is designed. Using the Eclipse platform to develop the application system software, including the registration and landing module, which ensure the user with legal identity enter into the system, use safety function, and directly enter the enterprise website from the interface at the same time;Thirdly, the friendly man-machine interface is developed by the powerful components function and SQLite database function of the eclipse and used the Android smartphone or tablet as the end of the control system. It realizes the control of the spectrometer hardware, user registration and landing, spectral scanning, data pretreatment, fault diagnosis and model call function.Fourthly, the monitor of spectrometer are studied and designed. These functions can provide support for remote fault diagnosis and maintenance of the instrument. This monitoring system uses SQLite database to establish the fault information table, which can realize the detection of environmental temperature and humidity, light source working temperature, WiFi working voltage, light energy detection and wavelength correction.Fifthly, the practicability of the system are tested. Taking alcohol content as the object, correction model is established by a sample of 50. The Mahalanobis distance discriminant method is applied to eliminating abnormal samples, the correction set and validation set are set by 7:3 ratio. Using Kennard-stone method to divide the pretreatment sample set, take 35 samples as correction set and 15 samples as a validation set. The prediction accuracy of the correction model is analyzed, and the measured results show that the correction and prediction errors are small. It is proved that the system is feasible for determination of alcohol content.