Made of lead-free ballast and glass, this combined form hydrometer is 381mm (15") long, and is serialized and conforms to the accuracy requirements for ASTM thermo-hydrometers. The temperature standardization is 20°C. This type of hydrometer is used in the food and beverage industries to measure % sucrose by weight in Brix. It includes a convenient, built-in thermometer with a temperature scale of 0/50°C and mercury-free blue spirit organic liquid fill. Note: Combined form hydrometers should be stored in a clean, dry, safe place, and should not be subjected to extreme temperatures. Enclosed thermometers should be used as a general reference only. For temperature-critical applications, a calibrated standard thermometer is recommended.