Design Of Portable Colorimeter System

Surface color measurement is of importance in a very wide range of industrial applications. Color is an important index of the industrial product quality evaluation. In some industrial fields such as color sorting and quality control, we only want to measure the color difference of two samples. Basing on the relevant theory of colorimetry, a colorimeter system is designed to meet the demand of test for color difference. This system can supply surface color measurement and its color difference evaluation using photoelectric integrating method. The system has these characteristics: portable, stable and cheap.By means of analysis and study upon performance of color sensor, the chroma theory and the method of color measurement instrument, a photoelectric inte-grating colorimeter is designed to distinguish two similar color samples. System parameters such as tristimulus values, lightness difference and chroma difference are given. The system can be widely used in many industrial fields including plastic, textiles, printing, food, book and so on.The designed colorimeter takes high brightness white LED as illuminant, takes silicon photodiodes as detectors, and uses the single chip AT89C52 as the core processor and control unit, which can perform data analysis and result display on LCD.The main contents are summarized as follows.1. The general design of colorimeter system. The configuration of this system and the color measurement scheme are clarified. The method of calibration of the system and the error evaluation of the system are put forwards.2. The hardware design of the system. The design contains signal amplification circuit,AD conversion,single chip microprocessor and liquid crystal display module. The parts of hardware and the design scheme are introduced in detail in this paper.3. The software of the system is described. The research consists of data acquisition and processing system, the set of interrupts, the calibration programming and so on.4. The Performance Analysis of this colorimeter system. The result and error Analysis for this system is given, the research is summarized, and some possible improvements are prospected and more excellent performance of this system is looked forward.