Various types of lamps have more or less service life. Recommended replacement for several types follow:
Simulated Daylight: 400 hours
Cool White Fluorescent: 4000 hours
Horizon: 2000 hours
Ultraviolet 30 Watt: 4000 hours
Illuminant “A”: 2000 hours
Ultraviolet 6 Watt: 4000 hours