Cold finger
A cold finger is part of the laboratory equipment used to generate a cooled surface. It resembles the outer shape of a finger and is the special shape of a cold trap .
The cold finger is usually part of a sublimation apparatus , but it can also be part of a cooler in laboratory apparatus for carrying out chemical reactions or in distillation apparatus .
The cold finger usually consists of a cavity into which a liquid (usually cold tap water) is fed and drained. In other embodiments, instead of tap water, ice , a mixture of ice and table salt or dry ice is used as the coolant.
Dark green crystals of nickelocene , freshly deposited after sublimation on a removed cold finger.
Sublimated camphor (camphor). On the cold finger the colorless pure camphor and the dark brown contaminated camphor.
A cold finger with a vacuum nozzle.
Cold fingers as part of a sublimation device.
Individual evidence
- ↑ aprentas (Ed.): Laborpraxis Volume 3: Separation methods . 6th edition. Springer International Publishing, Cham 2017, ISBN 978-3-0348-0969-6 , Chapter 10: Sublimation , p. 167-173 , doi : 10.1007 / 978-3-0348-0970-2_13 .