The Robinair 75240 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. It is used on transportation vehicles, such as cars, tractors, tanks, ships, etc., which use propylene or ethylene glycol for coolant and sulphuric acid for charging liquid. When a liquid (such as coolant or charging liquid) is placed on the prism, the light passing through it is bent. The more concentrated the liquid, the more the light will bend. The refractometer contains a reticle, or scale, that is enlarged through the eyepiece to measure this bent light. The values of the scale have been established to evaluate the coolant or charging liquid.

Warning: This product may expose you to chemicals including lead which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov