Introduction

A detailed discussion of the electronic circuits used in conjunction with radiation detectors would be out of place in the present monograph. The design of these circuits has become so specialized that they are no longer ‘home–constructed’, certainly not by the crystallographer to whom this text is primarily addressed. The aims of the present chapter are much less ambitious. They are

1. (1) to indicate what ‘black boxes’ are required in a diffractometer installation;

2. (2) to assist the crystallographer, who is contemplating the assembly of a complete installation from individual commercial units, in making his selection from the large range which is available;

3. (3) to describe the precautions necessary to secure a satisfactory performance from these units; and

4. (4) to indicate the amount of trouble–shooting which the user of the diffractometer may have to undertake himself.

It must be remembered that an automatic diffractometer is largely an electronic instrument and the user must have some acquaintance with electronic technology to ensure the correct functioning of his equipment. The brief notes offered in this chapter cannot supply the knowledge which can only be derived from general texts on electronics. The diffractometer user should also study more detailed discussions of detector circuitry (for example, chapter 11 of the monograph by Price, 1964).