The SA UVCON is a device for exposing materials to alternate cycles of florescent ultra-violet light & condensation.
The Unit provides a screening test for coatings, plastics, pigments & the like which may be specifically affected by the UV portion of sunlight spectrum along with moisture penetration. Screening test of this type can give early indications as to how the material must be expected to perform in a natural outdoor.
The SA UVCON uses eight FS-40 Fluorescent Sun Lamps as Light Source.
These Lamps are mounted in two banks of four each, are rich in Ultra-Violet energy between 280-350 watts at an operating voltage of 220 volts.
An electrical discharge within the tube generates Ultra-violet energy at 254 Nanometers which excites the Phosphor coating causing it to fluoresce & radiate approx. 85% of the lamp's energy between 280-350 Nanometers.
In the natural sunlight spectrum below 350 NM, accounts for only about 3% of the total radiant energy.
The UV below 310 NM produced by these lamps at sample face (50mm from the lamp) is several times greater than that of natural sunlight & is the principal cause for acceleration in a test.
The fluorescent sun lamp produces virtually no significant visible or infra-red energy. Lamp Intensity normally deteriorates by about 20% during 1600 hours of useful life & the lamps are changed on rotation basis. Every 400 hours a new Lamp is installed in each bank of 4. This method ensures reasonably uniform radiation at the sample face.
The condensation of SA UVCON is produced by heating water in a stainless steel sump of the Unit with an Electric Immersion heater. Natural convection causes saturated air to move up across the face of the exposed panels. Mounted in their rack these panels act as exterior walls of the Test Chamber. Ambient room air moving across the back of the Test Panels causes a temperature differential & dew droplets condense on the panel face. The condensation cycle allows water to form naturally free of mechanical & thermal shock with maximum purity