Testing Glycol percent by volume with a refractometer

I need to know the percent volume of my glycol?

.There are two methods to determine the percent concentration of glycol in a system. If using the MISCO Glycol & Battery Tester (7084VP or 7064VP), take a reading of the glycol on the freeze point scale and then cross reference the freeze point reading to the percent volume column on a physical property chart, available from your glycol supplier. If using one the MISCO Palm Abbe digital handheld refractometer, there are several scales available which directly display the concentration by volume of a glycol solution.