Digital refractometers are available to measure ethylene glycol and propylene glycol. These digital refractometers eliminate the uncertainty associated with mechanical refractometers. Samples are measured after a simple user calibration with distilled or deionized water. Within seconds, the refractive index and temperature are measured and converted into one of two measurement units; % volume or freezing point. The refractometers use internationally recognized references for unit conversion and temperature compensation for glycol solutions (e.g. CRC Handbook of Chemistry and Physics, 87th Edition).