The Central Tools Combination Refractometer for Coolant, Battery and DEF, No. 3R401, is designed to combine what is traditionally two products into one. The coolant scale reads from 20 degrees F to -60 degrees F for both ethylene glycol and propylene glycol. The battery scale reads specific gravity from 1.10 to 1.40 and determines the charge state of either recharge, fair or good. The addition of a scale for Urea (DEF) reads from 30 percent to 35 percent with a dominant line at 32.5 percent, which is the ratio required for proper operation of the emissions system. This tool helps confirm the proper mixture of DEF as well as prevent coolant related problems.
