In radiological protection, the protection quantities should be expressed in terms of measurable physical quantities

It is somewhat of a truism that is expressed in the often quoted statement that you can't go home again. In the days when life was simpler, we could assume that a measurement performed with a portable survey instrument yielding a value for exposure rate in terms of roentgens/hour was a sufficient approximation to the value for the dose equivalent rate or absorbed dose rate at a point in a radiation field. As our understanding of radiological protection grew more sophisticated, we found it necessary to introduce additional rigor into the definitions of the radiation protection quantities. As mentioned earlier, we demand a lot from the definitions of these quantities. They need to satisfy many conditions, perhaps too many. When they are examined from the point of view of a metrologist, they may be considered to be deficient in many respects. When they are viewed by a radiobiologist, they may appear to be naïve or overly simplistic. A radiation protection technologist at a nuclear power plant may have difficulty understanding their sometimes-subtle implications. The ICRU and ICRP have worked for quite some time to incorporate all the necessary requirements into the definitions of the operational and protection quantities. From the arguments of our debaters, one might conclude that after careful consideration of past developments, additional refinements will be devised in the future.