What does the cobalt blue glass do?
We had to look through a thin two inch by two inch “cobalt blue glass” to see the color of the element flame. But, I don’t know what the piece of “glass” is supposed to do. I think it has something to do with wave frequency and length?
Sunflower
on February 8th, 2012
If I remember correctly, it filters out the Sodium flare so you can see the color of the element being tested. Since Sodium contamination is very hard to avoid (it is found on your skin) and a very tiny amount flares a bright yellow, without the glass you see only yellow.
Seashells
on February 8th, 2012
I think it is used to filter out the color of the flame itself, so the color from the element present shows up better.
FunnyFish
on February 8th, 2012
It filters out the bright yellow sodium flame so that you can see the flame you’re looking for. Yes it has to do with frequency because frequency determines color. Cobalt glass is most commonly used in this fashion to look for the purple flame of potassium.