| Intensity |
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Lamp intensity is defined as the overall power of the lamp and is most often designated in watts. Also called power density, intensity refers to total lamp output across the entire electromagnetic spectrum. Lamp intensity generally affects rate of cure of particular products, since it is one of the factors determining the amount of light that actually reaches the product.
It is important to distinguish between basic lamp intensity and intensity or amount of light at the working surface. The quantity of light at the working surface is defined in either intensity units or energy units. Light intensity at the product surface, described by the term irradiance, is a measure of momentary exposure and is most often quantified in milliwatts/cm2. Light energy at the surface is a measure of cumulative intensity exposure (intensity x time), quantified as millijoules/cm2, and is simply:
mW/cm2 x seconds = mj/cm2
Measurement of irradiance (light intensity at the working surface) is essential in order to optimize cure conditions and maintain consistency in cure results. Easy to use equipment is available for this measurement. | 
