The HI96831 is a rugged, portable digital refractometer designed for the measurement of percent volume and freezing point of ethylene glycol based solutions. The HI96831 has a high accuracy of ±0.2% volume and ±0.5 °C freezing point and features simple operation that gives reliable results each and every time. All readings are automatically compensated for temperature variations and displayed within a 1.5 second response time. The sealed flint glass prism and stainless steel well are easy to clean. Just wipe with a soft cloth in preparation for the next sample.