In general, all whole body counters must have (1) a mechanism that reacts to the energy emitted by some kinds of disintegrating, or radioactive, atoms; (2) a device that displays or records these reactions; and (3) adequate shielding to exclude unwanted rays from other sources.

Figure 1 Types of whole body counters.

A The subject may be seated in a chair in an iron-shielded room and under a scintillation detecting crystal.

B The subject may lie in a bed that slides into the end of a hollow cylindrical tank filled with scintillation fluid.

C The subject may stand in a semicylindrical double-walled tank filled with scintillation fluid. (See [Figure 2].)

D The subject may lie on a wheeled cart and be wheeled beneath a shielded detecting crystal.