The Design Of The Droplet Analyzer Sensors And The Structure Of The Instrument

Drop Analyzer is the instrument which based on fiber-capacitive sensor, establish the drop traces, identify the liquid by qualitative and quantification. The main objective of this project is to improve the design of the droplet analyzer sensor device, hoping to get the best recognition performance by subsequently experimental analysis. The volume-based fiber drop traces which is measured by fiber-capacitive drop analyzer represents the curve about the light intensity signal, getting from fiber receiving end, the abscissa represents the instantaneous change of the droplet volume in the growth process. This expressions solve the problem that the time-based fiber fingerprint influenced by the stability of fluid supply system, excluding the impact of the uneven droplet growth rate and volatile of liquid, enhancing the measurement repeatability and comparability of fingerprint. Meanwhile, fiber drop analyzer and capacitive drop analyzer technology enable the droplet analysis involves more features of liquid, leading to a more comprehensive analysis and identification of the measured liquid.In terms of improvements in the sensor device, first, combining the fiber optic sensor and capacitive sensor by multi-sensor data fusion technology, designed a fiber-capacitive sensor to achieve the information complementary. In the droplet analyzer sensor, the dripper plays a vital role, using it to forming droplets and making the optical fiber enter the droplet. The shape the structure and geometry of dripper have close relationship with volume, contour and growth of droplet. Therefore, the core part of the droplet sensor is dripper. But until now, only a theoretically more appropriate inverted cone dripper was used on the project, other shapes are not applied to the project. So we changed the shape and size of dipper abide by the premise of the design principles, and using sample testing experiments to analyze the effects of different dripper structure on recognition results.For each measurement, in order to make the input and output fiber insertion depth inside the droplets remains the same, to ensure that the droplets fingerprint comparable. I designed different types of "fiber position adjustment device" and "adjustment pedestal" for the sensor. The adjustment device is used to against the fiber when fiber is inserted, it can make the height of the fiber is certain at each measurement. And it can achieve the function of adjusting the height of the optical fiber in accordance with the intensity of the signal in the experiment.The overall designing of the instrument affect the functioning of the instrument directly. In the instrument design, I consider the functional requirements first, ensure the fluid systems, development boards and sensors could be reasonable fixed inside the shell, and easy to use. Secondly, I consider the aesthetics, economy, security and other needs. Try to design the shell as small as possible, ensure it convenient to carry, and the cost is lowest and so on.