The Optical Design And Research Of A Liquid Level Measurement Device Based On Linear CCD

The liquid level measurement technology is applied widely in the fields such as modernindustrial production, water conservancy and hydroelectric power, national defense and so on.At present, if the temperature, the concentration of the liquid changes or the environment isvery bad, the measurement will be made a large deviation even can’t be done because of thelimited self-measurement principle. How to develop a high-precision liquid level measuringdevice meet different measurement environment are problems to be solved in the field ofmeasurement.This paper mainly focuses on a kind of real-time liquid level measuring device based onlinear CCD which is applicable to most liquid. The main contents include the optical designof the measuring device, the design of a feature extraction algorithm based on DSP,experimental calibration etc.First, the light path based on the principles of optics was demonstrated and designed inthis paper, the construction of optical modules was completed. Include the selection of lightsources, the design and optimization of linear light source base on LED, as the carrier of theliquid level features, the transparent glass’s inner diameter and thickness were analyzedbecause of their impact of the light road; And then then the structured process module basd onDSP was designed by the need for liquid level image processing. At the part of featureextraction, in order to extract the most stable results, several liquid extraction algorithms weredesigned and by comparing the best one was selected finally. And at last, the device wascalibrated and be tested, the results show that the accuracy and measurement stability of thedevices were up to expectations.This measuring device has the characteristics of high-accuracy, high-stability, can bemeasured online, and qualified majority measurement tasks of transparent liquid level inharsh measurement environments.