Johannesburg skyline 



Some spectra of Compact Fluorescent Tubes (CFLs)

The following spectra were obtained simply with the above setup. Note these are stretched out somewhat; We will try to align them with the above colour spectrum later.

(A) Visible light from mercury - still to come.

(B) Current technology CFLs

These all have similar characteristics:

  • The two expected mercury lines blue (436 nm) and green (546 nm)
  • Additional green and blue lines from terbium (Tb3+) - green (542 nm), just below the mercury green line, and blue (488 nm).
  • A significant red line surrounded by lesser lines, largely from  europium (Eu+3:Y2O3)

Osram f888 Cool white - somewhat lacking at the red end of the spectrum.
Osram f888 Cool white

Osram "Warm white" - Note substantial boost at red end.
Osram Warm white

Philips Genie "Warm white"
Philips Genie Warm white

Pro-view work lantern
Proview work lantern

(C) "Old-style" halophosphate phospors

These are unusual as they show a continuous spectrum over the green - red section. We see the two expected mercury lines blue (436 nm) and green (546 nm) plus some sodium (?) at 590 nm). 

"Simple choice" - Game stores house brand(?)
Simple choice

Osram 40 W fluorescent tube
Osram 40 W Cool white

(D) Some continuous spectra for comparison

100 W frosted incandescent lamp
100W incandescent