Kernco Instruments Co Inc's Model 11J16 battery/antifreeze tester is a handheld refractometer designed to indicate specific gravity, freezing point temperature, and battery charging levels.
To do the test, place a drop or two of the sample on the prism surface, hold it up to a light, and read directly propylene glycol (-60° to 32° F), ethylene glycol (-84° to 32° F) or battery fluid (1.100 to 1.400 specific gravity), depending upon the sample. The battery fluid scale also shows condition, such as “recharge,” “fair,” and “good.” The tester has a blue filter system that gives clear readings, and the test takes just a few seconds.
This refractometer weighs seven ounces and is 6" long. It comes with an adjustable knob for calibration and has a rubber eyepiece guard that shields out extraneous light. For additional details, contact Kernco, 420 Kenazo Ave, El Paso TX 79928-7339.