Del City offers hydrometers to identify if acids or other solutions are at their proper levels.

The battery hydrometer tests battery acid and suggests a low, fair or good rating in the range of 1.100 to 1.300 sg. The windshield washer hydrometer tests methanol, and the antifreeze hydrometer tests ethylene glycol on a temperature scale from -51 C to 0 C (-60 F to 32 F), suggesting that the solutions are properly mixed to prevent freezing.