How often should UV lamps be changed and what does that depend on?
a. UV lamps should be changed every 6-12 months, depending on the manufacturer's recommendations.
b. UV lamps should be changed annually, regardless of usage.
c. UV lamps should be changed every 3-5 years, depending on the level of UV exposure.
d. UV lamps should be changed every time there is a noticeable decrease in UV output, as indicated by a decrease in sterilization effectiveness.