The ShadeVision Dental Vision Instrument is designed to give years of trouble free use. It’s carefully tailored, calibrated, light source is expected to provide up to 140,000 individual measurements. This computes to roughly 78 lamp hours. To view the lamp odometer select the "System Screen"icon located to the left of the "Battery" icon on the LCD display. This icon is the picture of a ShadeVision instrument. The resulting "System Screen"will display the lamp hours used.