Cold finger

A cold finger is a part of laboratory equipment for the generation of a cooled surface. It is similar to the outer shape of a finger, and the special form of a cold trap.

Most of the cold finger is part of a sublimation, but can also be part of a radiator in the laboratory apparatus for carrying out chemical reactions or distillation apparatus.

The cold finger consists mostly of a cavity in a liquid (usually cold tap water) is turned on and derived. In other embodiments, an ice-salt mixture or dry ice instead of tap water ice is used as the coolant.

Sublimed camphor. On the cold finger of the colorless pure camphor, and the dark brown contaminated camphor.

A cold finger with a vacuum nozzle.

Cold finger as part of a sublimation apparatus.

• Laboratory apparatus