Burette Borosilicate Glass

A burette (also buret) is a device used in analytical chemistry for the dispensing of variable, measured amounts of a chemical solution. A volumetric burette delivers measured volumes of liquid. A traditional burette consists of glass tube of constant bore with a graduation scale etched on it and a stopcock at the bottom. The barrel of the stopcock may be made of glass or the plastic PTFE. Stopcocks with glass barrels need to be lubricated with vaseline or a specialized grease. Burettes are manufactured to specified tolerances, designated as class A or B and this also is etched on the glass.