In this video, we show you how to judge the purity of milk by surface tensiometer. In the video, we measure surface tension of pure milk, milk with SDBS ( sodium dodecyl benzene sulfonate ) and milk with SDBS ( sodium dodecyl benzene sulfonate ) and water separately. Surface tension of pure milk is kept almost same value when we measure it by surface tensiometer. And for the milk with SDBS we get the same result except the value is lower than the pure milk obviously. Then we can make a conclusion if the milk is added with SDBS or surfacant by the surface tension of milk you want to measure.  The result of milk with SDBS and water cannot kept same value. So, we can judge the pure of milk by the stability of measured result of surface tension. In another word, you can adjust the purity of milk by the value of surface tension and stability of measured result of surface tension by using surface tensiometer. In this video, we used Modified Wilhelmy Plate method to measure the surface tension of milk. You can find more information about our force surface tensiometer by visiting http://www.uskino.com 

https://youtu.be/wGPML5KhnNQ