Research On Lactose Concentration Detection Device Based On The Optical Rotation Method

Milk and dairy products are rich in nutrients, it is necessary in people’s daily lives. But the lactose intolerance of newborn caused by race, genetic or enteritis,and the lactose intolerance of adults caused by the lack of lactase, enables us to precise lactose content in dairy products annotations. At present our country only gives several lactose detection method in national standard, foreign dairy products could be divided into sugar and sugar free only, the standard of fine division of dairy products by lactose content is not given. This phenomenon is due to most of the lactose instrument are produced from abroad, the type of small,high price, complex operation, special type, large error, as high as 15%- 10%.Therefore, the majority of enterprises, especially small and medium enterprises are still using the traditional titration method, can’t measure the content of the lactose in milk and dairy products online and real-time. In today’s market, we need a convenient, efficient and high precision detection device.In this dissertation, on the basis of the existing rotation, using angle sensor to measure rotation angle, using angle display to display angle value, using LCD display light intensity directly, the lactose concentration detecting device is designed. Hoping the measurement error can be controlled less than 5%. This device with STC89C52RC+ as control chip, designed the analog-to-digital conversion unit, photoelectric detection unit, the microprocessor control unit,display unit and designed the related software to drive program. Finally calculate the concentration of a lactose solution by measuring the rotation angle.Meanwhile, the key issues of the precision of photoelectric detection circuit are analyzed. Using 3D printing technology to print the test-bed, without mold, low cost, can print the design into actual devices at any time, save the cost of development and research on the great degree, there are many different kinds of colors and materials, with black PLA to make the test-bed, further improve the detection accuracy. Finally, the feasible program is designed. Using this devicefor the experiments, and a mathematical model is established combining least square method and the one dimension linear regression. At the same time, verify a small change in temperature have little impact on the experimental results that can be ignored, and calculate the uncertainty of measurement.The correlation model established in this paper has a correlation coefficient of 0.95. The overall detection accuracy of the system is as high as 95%, and the measurement uncertainty of the device is 2.163g/L, which meets the design requirements. This system can be very good to achieve the online measurement of lactose concentration, it has a very high market prospects.