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I remember hearing the main issue is that the glass is made up of a significant amount of led so even if it was commercially feasible it would be legally imposs

I remember hearing the main issue is that the glass is made up of a significant amount of led so even if it was commercially feasible it would be legally impossible to sell, import or manufacture new CRT tubes due to the regulations many developed nations have in place.

willis936 3y ago
How are car batteries sold, imported, or manufactured?
- CTDOCodebases 3y ago
  That was the explanation I was given when asked. I imagine different regulations apply to different products. Also obviously different countries have different regulations. Lead makes up 20-25% of the contents of the glass of a CRT tube so I imagine that restrictions like those listed in the link below would cause issues. https://dtsc.ca.gov/restrictions-on-the-use-of-certain-hazardous-substances-rohs-in-electronic-devices/ https://dtsc.ca.gov/restrictions-on-the-use-of-certain-hazar...
- elzbardico 3y ago
  There are exemption. And if you think of it, it is a lot easier to properly dispose and recycle the plates in a car battery than in electronics solder or glass.
jdietrich 3y ago
I can't speak for any other regulations, but the EU's RoHS has a specific exemption for lead in the glass of cathode ray tubes. CRTs are still being actively manufactured, primarily for avionics and military applications. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02011L0065-20230301 https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A... https://www.thomaselectronics.com/manufacturers/ https://www.thomaselectronics.com/manufacturers/ https://moores-glass.co.uk/products/cathode-ray-tubes/ https://moores-glass.co.uk/products/cathode-ray-tubes/
- nickt 3y ago
  Fantastic, thank-you. Every day continues to be a school day!
mrob 3y ago
Lead glass is only used for the back and sides of the tube. It can't be used for the faceplate because x-rays make it turn brown. Instead, barium-strontium glass is used for the faceplate. It seems that use of lead is only a cost optimization, and the whole thing could use barium-strontium glass instead. Searching for "lead glass CRT browning" on Google found this sample chapter from an unidentified book, provided by the The Society of Photo-Optical Instrumentation Engineers, which includes some details: https://spie.org/samples/TT54.pdf https://spie.org/samples/TT54.pdf
- NL807 3y ago
  The chapter is from: Kenneth Compton, "Image Performance in CRT Displays", SPIE Tutorial Texts in Optical Engineering Vol. TT54
- wkat4242 3y ago
  It's kinda mad we used to stare at an X-Ray gun though :) especially the ones in the 80s didn't quite filter all of them out.
  - deleted 3y ago
    [deleted]

willis936 3y ago

How are car batteries sold, imported, or manufactured?

CTDOCodebases 3y ago
That was the explanation I was given when asked. I imagine different regulations apply to different products. Also obviously different countries have different regulations. Lead makes up 20-25% of the contents of the glass of a CRT tube so I imagine that restrictions like those listed in the link below would cause issues. https://dtsc.ca.gov/restrictions-on-the-use-of-certain-hazardous-substances-rohs-in-electronic-devices/ https://dtsc.ca.gov/restrictions-on-the-use-of-certain-hazar...
elzbardico 3y ago
There are exemption. And if you think of it, it is a lot easier to properly dispose and recycle the plates in a car battery than in electronics solder or glass.

jdietrich 3y ago

I can't speak for any other regulations, but the EU's RoHS has a specific exemption for lead in the glass of cathode ray tubes. CRTs are still being actively manufactured, primarily for avionics and military applications. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02011L0065-20230301 https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A... https://www.thomaselectronics.com/manufacturers/ https://www.thomaselectronics.com/manufacturers/ https://moores-glass.co.uk/products/cathode-ray-tubes/ https://moores-glass.co.uk/products/cathode-ray-tubes/

nickt 3y ago
Fantastic, thank-you. Every day continues to be a school day!

mrob 3y ago

Lead glass is only used for the back and sides of the tube. It can't be used for the faceplate because x-rays make it turn brown. Instead, barium-strontium glass is used for the faceplate. It seems that use of lead is only a cost optimization, and the whole thing could use barium-strontium glass instead. Searching for "lead glass CRT browning" on Google found this sample chapter from an unidentified book, provided by the The Society of Photo-Optical Instrumentation Engineers, which includes some details: https://spie.org/samples/TT54.pdf https://spie.org/samples/TT54.pdf

NL807 3y ago
The chapter is from: Kenneth Compton, "Image Performance in CRT Displays", SPIE Tutorial Texts in Optical Engineering Vol. TT54
wkat4242 3y ago
It's kinda mad we used to stare at an X-Ray gun though :) especially the ones in the 80s didn't quite filter all of them out.
- deleted 3y ago
  [deleted]