General structure of a high vacuum system

Although the structure and components of high vacuum systems (h.v.s.) will be discussed in detail in Chapter 2, it is essential for an understanding of what follows to give here an outline of what is involved (see Fig. 2.1.). 

Almost all the high vacuum systems with which we will be concerned have at one end a rough pump, usually a rotary oil pump, capable of attaining ca. 10 Torr. This is followed by a high vacuum pump which can attain ca. 10 Torr, which is followed by a cold trap, the purpose of which is to condense out any volatile matter to prevent it entering, and possibly 

---