9-8. Fixture CleaningThe cleaning of internal and external optical lenses and/or mirrors must be carried outperiodically to optimize light output. Cleaning frequency depends on the environment inwhich the fixture operates: damp, smoky or particularly dirty surrounding can cause greateraccumulation of dirt on the unit’s optics. Clean with soft cloth using normal glass cleaning fluid. Always dry the parts carefully. Clean the external optics at least every 20 days. Clean the internal optics at least every30/60 days.