Thermco GW071H Glass ASTM/API Combined in Stem Hydrometers, ASTM 71H, 1 to 11° API Range, 0.1° API Division, 30-220°F Temperature Range, 380mm Length

These are high precision hydrometers calibrated to the highest standard that exceeds the exacting ASTM standards. Made from the finest materials available; the glass is free from imperfections, has the suitable thermal properties for the entire temperature range that would be subjected and resists any reactions from chemical agents. Each hydrometer has been calibrated against NIST standards and furnished with a NIST traceable certificate.