Throughout this book an effort has been made to use Si and SI-derived units, but the diversity of the field and the, often independent development of areas that comprise it, have led to well-established use of non-SI units in some cases.

Where that was the case, we provide conversion in the chapter text or figure captions, if the figures that are suitable for the text, use non-SI units. Here we summarize the SI, SI-derived and other units, to facilitate use of the various parts of the book.