The Design Of A Real-Time Liquid Refractive Index Measuring Device Based On Linear CCD

With the rapid development of science and technology, the measurement of refractiveindex is playing an increasingly important role in the industrial productions and laboratorystudies. We can easily identify the type of liquid substances, ratio of mixture and otherparameters by the refractive index of liquid. So the measurement of refractive index is widelyused in winemaking, chemical engineering, pharmacy, sugar refining, repast and otherindustries. With the automation technology applying in industrial production, the industrialproductions are gradually developing towards the direction of automation and networking.We provided a novel optical measuring approach as well as the correspondent device,which features with fast, portable and automatic in refractive index measurement based on anapplication of automatic industry.Based on the refraction law of light, if a bunch of light incident on the boarder of twodistinctive mediums with a constant angle, the refractive angle would changed with thevariation of refractive index of mediums. In the first beginning, a special trapezoidal glassprism with the optimal parameters was designed after compacted analysis of the impact to themeasuring precision and resolution by the bottom angle, bottom margin, and height.Consequently, the CCD measuring skill was adapted in this article to realize the automaticmeasurement. The light signal would transfer to a analog electron signal via a CCD, after aAnalog-Digital converter, this analog signal would fourthly convert to a digital signal so thatthe location of the refracted light spot would be efficient computed by processing this digitalsignal by the high performance of DSP chip. What is more, we designed the relatively circuit,utilized the CAN bus, which was most prevailing protocol in recent industry communication,as the communication interface. In the mean time, an host software was developed to receiveand store measuring results.In the last section of this paper, some data and figures of the test experiments and erroranalysis was presented, we also pointed out a few defects of the designed device and providedthe correspondent modifying methods.