Research On The Measurement Method Of Composition Content In The Typical Emulsion Based On Photoelectric Technology

An emulsion is a milky white liquid which is a mixture of more than two liquid or solid. For example, natural concentrated latex is a typical emulsion. Natural concentrated latex is usually extracted from containing rubber plants, and the rubber, which is one of the four important industrial materials (steel, petroleum, coal, rubber), is made of natural concentrated latex. The quality and price of natural concentrated latex are closely related to its dry rubber content. Milk, which contains much water, protein, fat and carbohydrate, is also a typical emulsion. The fat content in milk is one of the key factors to determine the quality of milk. The determination of dry rubber content in natural concentrated latex as well as the determination of fat content in milk is of significance to guide production and application of the latex and milk.This paper adopts natural concentrated latex and milk as the research object, and puts forward a measurement method and system of composition content in typical emulsion based on photoelectric technology. According to the principle that the tested composition content is related to the diffuse reflectance absorbance of the sample, several model equations are established using linear regression analysis after the relative diffuse reflectance absorbance of many samples are measured and the composition content in unknown sample can be predicted through these equations. This paper studies the influence of temperature variation on relative diffuse reflectance absorbance of the sample, and five model equations are established through the measurement data in five different sample temperatures. Furthermore, an analysis of prediction effect and testing parameters of these equations are carried on in this paper in order to find out the best model equation and sample temperature. Finally, this system realizes the determination of dry rubber content in natural concentrated latex as well as the determination of fat content in milk.The contents as follow are mostly researched.1. An annular photoelectric measuring system is designed in this paper based on photoelectric technology, in which the light sources encircle the photographic module for the sake of composition measurement in emulsion.2. The hardware design of the system. A preamplifier circuit and second stage amplifier circuit are designed in this paper based on the principle of micro-current amplifier and output characteristics of small signals; according to the output voltage variation of samples in different composition concentration, an A/D converter is designed in this paper ,which is fit to the sampling precision; a fast temperature control module is designed in this paper based on TEC ( Themoelectric Cooling Modules); a MCU (Micro-Controller Unit) module is designed in this paper, which includes the reading, processing, displaying of the signals and controlling of other peripheral equipments. 3. The software design of the system. The TEC temperature control module is studied in this paper, such as realization of the temperature control program and design of the PWM (Pulse Width Modulation) wave; signal processing program is studied in this paper, which includes digital filtering of the data, calculation of the diffuse reflectance absorbance, calculation of the standard model equation and displaying of the result.4. Establishment of the model equation. Several model equations are established through the measurement data in five different sample temperatures (25℃, 30℃, 35℃, 40℃, 45℃). In addition, an analysis of prediction effect and testing parameters of these equations are carried on in this paper in order to find out the best model equation and sample temperature.