Guide to UV Measurement
Power Supply
The power supply provides the electrical energy required to “ignite” the plasma in a UV lamp (bulb).
Power Classification
UV curing systems are rated by the power applied to the system. The incoming AC electrical energy required to power the lamp, divided by the lamp length gives a ‘general' classification for the system. The units, “watts per inch” (200-600) or “watts per cm “ (80-240) do not indicate the amount or type of UV produced or the amount of UV that reaches the cure surface. A 300 W/inch lamp, 10 inches in width, requires 3000 watts of incoming power. A 300 W/inch and a 120 W/cm system each have the same equivalent applied power but the amount of UV produced can be very different. Irradiance values from common systems range from 100 mW/cm² to 10 W/cm² of UVA. Spot sources may produce even higher values.
Power Supply Construction
Power Supplies utilize a variety of technologies to create the required electrical current. Included is the traditional ballast type and electronic or solid state ballasts. High frequency power supplies have also emerged recently. Features include multiple power levels, either stepped power (200 300, 400 W/inch) or variable (step less) power that provides the operator with the ability to change power levels as a percentage of total applied power.