| The illuminometer is an instrument for measuring luminosity and brightness,which can realize the quantitative measurement of radiation and stray light.The illumination meter has important applications in the light calibration,agricultural plant light detection,military night vision test,reverse reflection material test,vehicle lamp fault detection,and experimental research.In this paper,aiming at the real-time measurement of stray light,an intelligent illuminometer for measuring the luminous flux is designed to realize the real-time and rapid measurements of the large dynamic light flux ranging from 5×10-6 lx to 2×104 lx.The system uses a high sensitive photomultiplier(HAMAMATSU H6780-03)as the detector to measure the weak ray flux of 5×10-6 lx,and designs an optical processing system constructed by double attenuation filters to realize the measurement of the large dynamic range light,and selects the high responsiveness programmable controller FPGA as the core processing unit to realize the fast processing of the data and the intelligent control of the measurement range of the luminous flux.The work in the paper mainly includes two parts:one is the technical realization of the measurement of large dynamic range luminous flux,and the other is the technical realization of intelligent measurement of luminous flux.For the measurement of luminous flux with large dynamic range,two neutral attenuation filters are selected and logically combined to realize the measurement of light flux in 10 orders of magnitude.The ZEMAX simulation results show that the optical processing system based on double attenuation filters can achieve the measurement of light flux in the range between 5×10-6 lx and 2×104 lx.For the intelligent measurement of luminous flux,the system selects FPGA as the center processing unit,which is used to process the data and control the motors to set the measurement range of the light flux.After the photo-electric conversion,amplification and data sampling,the FPGA performs the noise reduction processing,and completes the functions of fast dynamic refresh display and automatic range switching.According to the system design,the prototype of the intelligent illuminometer is mechanically designed and the preliminary experimental measurements are carried out.The measurement results show that the designed intelligent illuminometer can realize the intelligent switching between the measurement ranges of the luminous flux,and realize intelligent displaying in different modes,including photocurrent,illumination,luminous flux and so on. |
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