Detection of the IR, visible, and UV spectra using arc lamp on TV camera.

Limits of visibility: the visible spectrum, infrared and ultraviolet. White light from a carbon arc passes through a slit and is sent through a diffraction grating, creating a full spectrum focused on a white screen. A zinc sulfide screen will phosphoresce when inserted into the dark region of the spectrum beyond violet, showing that there are ultraviolet rays that our eyes do not detect. Also, a small TV camera aimed at the spectrum detects light in the dark region past red, indicating infrared rays that are not visible to our eyes. The small TV camera also shows the visible region and some of the ultraviolet region as well. The instructor can point to the areas that seem dark to our eyes, yet on the monitor they are brightly lit.