Design Of Intelligentized Whiteness Measuring Instrument

In the printing and packaging fields, paper has been widely used as an important information carrier. Whiteness that is one of the main parameters of the physics-optical properties of paper is an important indicator to measure the performance of paper and paperboard, so the exact value of whiteness measurement is of great significance for improving the quality of printed matter. Double optical path system of photometric measuring-whiteness instrument that is designed, based on the dialogue-depth analysis of whiteness measuring methods and research of instrumentation for intelligent design. Photovoltaic cell is used as an optical signal acquisition front-end to achieve photoelectric conversion. Through using of programmable controller, a single-chip constitutes the core of the optical signal acquisition conversion systems, so as to realize the value of the measurement of whiteness. A good man-machine interface is a essential component of the modern intelligent instrument, and the measuring instrument uses touch-screen that is more advanced at present to display and control.The main contents and innovation are follows:1. Whiteness measuring methods and application status have been analyzed, and according to the relevant national standard ("Whiteness Determination Act about paper and cardboard 45/0 directional reflection method" QB/T 2804-2006 (GB8940.1 old edition)) to analyze in depth corresponding contents on 45/0 whiteness measurement, and considering existing problems in the measurement of paper whiteness - different measurement values as vertical and horizontal tropism, and a new type of optical design - "double optical path" optical system has been proposed so as to effectively reduce the paper-directional influence.2. According to the theory of optical measurements and combining with physical quantities required for whiteness measurement, an optical signal acquisition device - photoelectric cell has been collected, its conversion is efficient and linearity is very good. Corresponding conversion circuitry has been constructed based on optical working principle. 3. Theoretical analysis to relationship was done between the physical quantity measured by the photocell and physical quantities required by whiteness measurement, according to the hardware circuit design, theoretic formula was educed and eventually programmed.4. About man-machine display interface design. After practice-accounting, "limited" display area of liquid crystal displays was rational distributed to achieve the design of measurement function keys required, and through the matrix extraction, the "graphics" is quantified the "digital", and touch-control technology was used.5. According to whiteness measurement-related theoretical research, hardware structure was built, including the mechanical structure of measuring-meter and hardware circuit. In accordance with design requirements, the main structure of instruments used easily machined aluminum materials6. Program was compiled for microcontroller, including whiteness measurement,LCD, touch screen and other programmable device drivers.7. After assembling and debugging prototype, experimental data were collected and analyzed. According to the practical operation of the equipment, structural analysis and so on, shortage and corresponding measures for improvement were proposed.