cstanhope@social.coop ("Your friendly 'net denizen") wrote:
TIL about the use of tritium in exit signs:
https://www.epa.gov/radtown/tritium-exit-signs
Via:
cstanhope@social.coop ("Your friendly 'net denizen") wrote:
TIL about the use of tritium in exit signs:
https://www.epa.gov/radtown/tritium-exit-signs
Via: