Design of Color Luminance Meter
|Keywords||Luminance Meter photoelectric integral cosine corrected correlatedcolor temperature photoelectric convert microprocessor|
in the aspect of lighting design, photography engineering and trafficsafety, modern industry for illumination design requirements is becoming more andmore strict, the application of illumination measurement is becoming more and morepopular. The measurement of illumination is not limited to accuracy improvementand static single point measurement, more requirements are to achieve theinstantaneous dynamic multi-point measurement, to achieve simultaneousmeasurement of illumination, color temperature and other photometric parameters,to achieve measurement of high accuracy and high stability.This design of color luminance meter is based on single chip microcomputer,and it can realize measurement of large scale, high accuracy, and instantaneousdynamic response with all photometric parameters. The specific work includes:(1) Optical part. In the aspect of photometric parameters calculation, adaptmethod of area divided and linear interpolation to optimize the algorithm of colortemperature and dominant wavelength, the adaption method can reduce calculationtimes and prove calculation speed and accuracy. In the aspect of optical structure,design spherical shell-shaped cosine corrector to eliminate the influence of testangles to test accuracy, and verify its effect of correction by Tracepro. Under theevaluation method of smallest proportion of total error area, optimize the matchingof corrected filters, put forward the optimization formula of corrected filter’sthickness under the influence of oblique beams, and verify its correctness byexperiments.(2) Circuit part. Complete design of+3.3V、-3.3V and0.3V regulator buckcircuit module based on typical application of specific chips, to power control panelsand photoelectric sensor. Choose6photoelectric sensors S1133and besymmetrically distributed to accurately collect light signals. By the selection andcontrol of microprocessor to analog switches, and get programmable gaininstrumentation amplifier to get the wide measurement range of0~99990lx, at the same time to get high accuracy of A/D transition and high test precision. Chooseanalog switch CD4052to set test channels, and guarantee test sequence. ChooseSTM8L101F3microprocessor to control hardware circuit and make signaltransmission with PC by serial communication.(3) Software part. Finish software design of single chip microprocessor and PC,write programs to make programmable gain while testing and communication withPC. In PC part, finish system configuration module to guarantee test sequence, finishdesign of communication with microprocessor, finish operation of chromaticityparameters and interface design.