What are inspectors using to detect the type of lighting found in residential applications? I need a meter to help detect CFL and LED lights so I don't have to get a ladder and remove shrouds.
If the question is "incandescent vs. compact fluorescent" OR "cfl vs. LED" -- then a diffraction grating will help. Go to a toy store and find the little cardboard glasses with plastic lenses that make every light bulb look like a rainbow.
See the attached handout. Incandescent lamps radiate across all visible wavelenghts, so in a diffraction grating you see a spectrum of colors all blended together. CFL's have 4, 5 or 6 phosphors blended together. The lamp makes light that we see as "white", but in fact each phosphor radiates at a very specific wavelength. Through a diffraction grating, you can see multiple images of the light source, each with the different color produced by that phosphor.
WHITE LEDs are doped to radiate across most of the visible spectrum. So a diffraction grating shows the same "smeared" continuous specturm as an incandescent bulb.
You can see this effect even if the lamp is in an enclosed luminaire -- the image of the luminaire will take on the property of the light source inside it.
So, in an older home that has not seen dedicated energy efficiency work recently, the question is probably "incandescent or CFL?" A diffraction grating will show the difference. In a home where the owner pursues energy savings, the question is probably "CFL or LED?" A diffraction grating will sort them out. If the space could well have incandescents AND LED lamps -- good luck.