According to the North Carolina State University Chemistry Department, burette clamps are adjustable devices that secure burettes to laboratory ring stands. They are made from corrosion-resistant metals. Single burette clamps hold one burette, test tube or flask, and double clamps hold two. Double burette clamps also accommodate flasks and test tubes.
Burettes are staples of analytical chemistry labs. They are clear, graduated liquid dispensers with an adjustable spigot at the bottom end that releases the contents in varying amounts. Burettes are extremely accurate when they are used correctly. Precise measurements require the user's eyes to be exactly level with the gradation markings. If this does not happen, the burette appears to contain more or less liquid than it actually does, depending on the position of the user's eyes relative to the vessel.
There are several types of burette. A volumetric burette measures liquid based on volume, and a weighted burette measures liquid by weight. A third form of burette is the piston burette, which lacks the spigot found on other types. Piston burettes are akin to large syringes that dispense chemical solutions through manipulation of a plunger.
Some piston burettes are manual devices, while others are digital. The plunger of a manual piston burette is connected to a click wheel that the user adjusts by hand. Digital piston burettes are manipulated through a computer interface.