First published in 1979, this volume presents an elementary and, as far as is practicable, non-mathematical introduction to radiation dosimetry. Where it proved necessary to use mathematical notation, it was kept to a simple level. The volume treats dosimetry from first principles, dealing with the interaction of the various radiations with matter, then defining dosimetric quantities and units and showing how the more important ones are measured. It concludes with a brief chapter on radiation protection. Although a number of dosimetric systems are described in some detail the treatment is by no means encyclopaedic. SI units appear throughout, including some which were not yet in universal use when the book was first published. Where it was considered necessary, the older non-SI units were also defined and conversion factors were given.