出典:Wiktionary
出典:Wikipedia
出典:『Wikipedia』 (2011/06/14 20:02 UTC 版)
A bell jar is a piece of laboratory equipment used for creating vacuums. It can be similar in shape to a bell, and can be manufactured out of a variety of materials (ranging from glass to different types of metals). A bell jar is placed on a base which is vented to a hose fitting, which can be connected via a hose to a vacuum pump. By pumping the air out of the bell jar, a vacuum is formed.