7-1/2″ API Thermo Hydrometers
Approximately 190mm (7-1/2″) Length. Thermometer in body. Not ASTM designated, but made to similar specifications. Popular due to the smaller sample amount (approx 6 ounces) ounces needed to obtain a reading. Made to the same demanding tolerances as ASTM hydrometers. Accuracy: +/- 1 scale division.