What is the role of anhydrous ethanol in the pour point and freezing point tester?

In the pour point tester test, what is the effect of adding anhydrous ethanol to the outer test tube?

The purpose of adding alcohol to the outer test tube is to prevent the sample from being overcooled. When performing low temperature tests, such as freezing point or pour point tests, the ambient temperature outside the test tube needs to drop quickly to below the expected temperature of the sample in order to accurately measure. In this case, alcohol is used as a refrigerant because it remains liquid at low temperatures and has good heat transfer properties, which helps to evenly cool the sample. In this way, the sample can be prevented from freezing, thus ensuring the accuracy of the test results.