Rationale

1. Scope * 1.1 This test method covers the use of a portable refractometer for determining the approximate freezing protection provided by ethylene and propylene glycol-based coolant solutions as used in engine cooling systems and special applications. NOTE 1— Some instruments have a supplementary freezing protection scale for methoxypropanol coolants. Others carry a supplemental scale calibrated in density of specific gravity readings of sulfuric acid solutions so the refractometer can used to determine the charge condition of lead acid storage batteries. Also, other instruments include a scale for the measurement of diesel emission fluid (DEF). Other instruments also include scales for windshield wiper fluid, both for ethanol-based or methanol-based fluids. These additional scales are supplementary and are outside the scope of this paper.