UV radiometry in dermatology.

UV radiometry in photodermatology remains in an unsatisfactory state, which has been highlighted and, in some respects, worsened by improvements in UV detector technology. Complex, fundamental problems are involved, but matters have not been helped by a failure to recognize the clear distinction between those UV measurements which aim at accurate radiometry, and those which aim only at long-term consistency in a particular irradiation technique within a department.