Development of smartphone spectrometer for juice quality examination
|關鍵字:||手機光譜儀;食品安全;Smartphone spectrometer;food safety|
In this thesis, a spectrometer using a smartphone built-in CMOS camera as a light detector and diffraction grating as a dispersive element was developed. A handheld case designed with SolidWorks and fabricated by 3D printing was used to assemble necessary components to realize a smartphone spectrometer system. An optical fiber was used to couple the light source and illuminated at the sample. The transmitted or reflected light was then gone through a slit to improve the spectral resolution. The light was then going through a cylindrical lens before incident on the grating. The dispersed light was then measured by CMOS camera. Three LED with known wavelength was used to calibrate pixel and wavelength relationship such that the spectral information can be transferred into spatial information on the CMOS pixels. To demonstrate the capability of the smartphone spectrometer, two different experiments were performed. Based on the absorbance on a particular wavelength due to the chlorophyll content, the smartphone spectrometer was used to determine the state of ripeness. Also, based on the difference in absorbance between pure juice and water, the actual concentration of apple juice from different vendors can be determined. We believe that smartphone spectrometer can be further applied for other applications such as food safety monitoring, disease screening, and etc.
|Appears in Collections:||Thesis|