This chapter is deliberately placed here in this book as it is the penultimate procedure we must consider during sample preparation. Once cleaned, the specimen either goes directly into the specimen chamber of a scrupulously clean SEM or via the charge elimination procedures discussed in Chapter 11. This is not to suggest that this is the only time cleaning occurs; it is a continuous and repetitive process during sample preparation to remove every thing that is not an original and integral part of the sample. If a particular preparative procedure contaminates the specimen, clean it off before going on to the next task.
The dictionary definition of the word clean is “free or relatively free of dirt or pollution” and “unadulterated or pure in various ways.” The words “various” and “relatively” reveal that complete cleaning is an activity that is very difficult to achieve. For example, the proper cleaning of both sides of a domestic window is not an easy task.