PIRA: 6D20.00


  • Showcase bulb and socket
  • Variac
  • Diffraction grating 3 paneled screen


  1. Place the screen in front of the bulb. Plug the bulb into the variac, turning it up until the bulb glows brightly.
  2. Observe the spectrum through the screen.
  3.  Turn down the variac and as the bulb cools, notice the loss of the blue end of the spectrum