Investigation On The Content Of Milk Lactose With The Method Of Laser Refraction

In this paper, we theoretically and experimentally researched the content of lactose in milk through the method of laser refraction. A He-Ne laser's homochromous beam impacts on a triangle sample case("â–³"type) which contains lactose solution, and it's refractive beam is then recorded by a CCD position detector. Different contents mean different refractive indexes that are determined by different exiting beams'positions, which can be determinately recorded by CCD. So, a unique function (obtained through detecting exiting beams'positions in CCD for a series of lactose samples with different contents) describing lactose contents in quality to light position, as variable, exists. Position to content relationship might be got by experiment as standard data. Hence, lactose determination can be done through detecting exit beams'positions, which will be later compared with the standard function. Our prospective accuracy of lactose determination in milk is up to 0.1%. According to determination requirements and principles, hardware designing, making and debugging of determination system were carried out and controlling software was compiled as well. A series of experiments, classified into two sorts, were done using this determination system. The actual experiments through "â–³"type sample case's determination method proved that this method turns out to be accurate and fulfils our goal, up to 0.1% accuracy. Through our theoretic research and gauging experiments, we've known that the key point of the method is the shape of the cases. So we have improved the experiment setting, that is to say, the bi-triangle sample case replaces the mono-triangle sample case. Under the same testing circumstances, the test of the bi-triangle sample case is higher than that of the mono-triangle in accuracy. When the change of lactose content is 0.1%, we use the bi-triangle sample case to reduce the scale of experiment setting and furthermore it is propitious to the instrumentlization and commercialization of the setting. Our country's milk industry is very backward compared with the developed nations. The detecting of milk quality is one of the most fragile parts. For these, we can say that the successful development of quickly measuring instrument of lactose in milk will make great contribution for promoting the progress of our country's milk industry and improving milk quality. It would have widened market prosperity, huge economy and social profit. Especially, the instrument will be greatly meaningful for enhancement of international competence of our country's milk industry.