Guide to UV Measurement
Irradiance Profile
Irradiance Profile is the time (or distance) display of the instantaneous Irradiance. It is the shape of the time exposure under a complex source. In linear processing, it is also the pattern of the focus of the lamp on the surface.
The Irradiance profile includes the peak of irradiance, important to depth of cure. Its shape is dependent on the optics of the lamp (type of reflector) and its position. It can be used to describe the focused quality of a lamp. It is also effective in determining if a lamp is in a desired position.
The measurement of energy density incorporates irradiance profile , the wavelength range of interest, and time. The exposure profile is characteristic of any lamp design. It is not possible to increase the peak-to-energy ratio of a lamp -- this is determined by its design. Increasing lamp power does not alter the peak-to-energy ratio (at any speed). Typically, once a lamp is selected, the only controllable variables in a curing process are speed and lamp power. This gives the (unfortunate) impression that energy ("dose") is the only measurement needed. It also leads to the unfortunate conclusion that increasing electrical power is the only way to increase irradiance.