Guide to UV Measurement
“Dose”
“Dose” is a term used in higher-energy radiation, for example, in ionizing radiation such as gamma and X-ray. It is also used in the Electron-Beam (EB) technologies. It is defined as energy absorbed per unit volume or per unit mass. Its units are the gray or kilogray (1 Gy = 1 J/kg).
“Dose” is not a UV term nor is it a term defined in optics. Because UV and EB share some common elements in chemistry, the term appears to have “leaked” into the UV curing vocabulary. Although, the term unfortunately persists, it is gradually falling out of use in UV.
The preferred terms are “energy density” (or simply “energy”) or “exposure.”
It is important that the wavelength range be understood or stated when reporting any energy data.