In my researching for coating tubes I have been collecting a bunch of literature around the matter. This Russian book, the "Biblioteka Svetotekhnika" printed in 1990, (originally 1977) had an interesting method around checking the thickness of the phosphor coating on the inside of the tube.
As seen in figure 9 here, it involves a light source in a box that your test tube goes into and a photocell sits at the top for a resistance reading of the light going through the phosphor coating of tube- a quick way to measure thickness.
They are using an incandescent bulb on isolation transformer and variac along with a Selenium photocell. I will be using a neon filled tube that I might dim and a CDS cell adhered to the top hole in my PETG box.
Thanks 3D printer.... I guess I could have made this in cardboard... but the printer makes it too easy.
#tools #recreation #specialtools #tubecoating #neon #nerd #craft #customcolors #fluorescent #artist #3dprinting #oldbook #brooklyn #light #nyc