When a liquid (such as coolant or charging liquid) is placed on the prism, the light passing through it is bent. Scale range: 32 degree f to -60 degree f Can also be used for checking the strength of electrolyte solution batteries Automatic temperature compensation Free delivery and returns on eligible orders of £20 or more. Buy Seymour Duncan Alnico II Pro APH-2S Humbucker Zebra Pickup Set with Slash Signature at UK AUTOUTLET Fahrenheit Antifreeze Refractoeter with ATC Function for... Battery Fluid Refractometer - Ade Advanced Optics Martinique The hand refractometer is a portable, precision optical instrument used for measuring the freeze point of engine coolant and the operation state of battery charging liquid. Used on transportation vehicles such as cars tractors tanks ships Refractometer Honey Celcius Chart ATC Glycol Antifreeze/Battery/Cleaning Fluid Prism Optic The values of the scale have been established to evaluate the coolant or charging liquid. For measurement of ethylene and propylene glycol and brake fluid It can also be used for checking the strength of electrolyte solution batteries. This aaogabf100atc can be used for measuring the freezing point of either Propylene or ethylene glycol based cooling systems. The more concentrated the liquid, the more the light will bend.