Thermco's offering of hydrometer include glass & plastic Hydrometers in the following scales.. Specific gravity baume and density hydrometers, ATSM & API Hydrometers, Alcohol Hydrometers, Brine Brix Hydrometers and Combined Form. Thermo-Hydrometers. Thermco's Hydrometers are commonly found in the Petroleum industry, Wine, Brewing & Distilleries industries and Chemistry / Pharmacology industries. Each hydrometer is individually serialized and provided with a Hydrometer Certificate of Compliance and Traceability (attached). Hydrometers are suitable for calibration resulting in a DAkks or ISO 17025.