How do you look at bright lights safely without causing eye problems? Do you use a welders mask? Or some type of reflective surface, such as a turned off smartphone screen?

I do it with the turned off screen, it makes for great viewing of mercury vapor arctubes. I also used my pair of aviators. If you have a busted merc lamp, it'd be better off using a welding mask, arc eye is no laughing matter. I know from experience.

Yea, I just noticed that recently. I used to just stare at the lights. Probably why I am half blind now.

I have never come across a broken HID lamp where the outer envelope with the phosphor as broken, but the arc-tube still works. How dangerous is it? Is it fairly common? I read an article about this happening in a school gymnasium with a broken MH lamp, and the kids got sunburns and arc eye.

Also, I have some cheap no-name CFLs with a bad phosphor, and they give me headaches. The CFLs plastic base turned yellow from the UV within 1,000 hours.

Mercury vapor is the worst since they produce lots of short wave UV (which is why u coated fluoros with special glass are used as germicidical lamps.)   They do have special lamps (such as Westinghouse lifeguards or durotest safety vapor) that have a filament that will burn up when exposed to air.

Mercury vapor is the worst since they produce lots of short wave UV

HID are3 not better in that respect, it is in fact the same mercury there...

Mercury vapors won't warm all the way since the glass insulates it. It isn't as bad as breaking the arc tube itself and inhaling the vapors.

When they are not warmed up all the way the visible light amount drops a lot, but the UV amount does not drop to the same extent, so the difference you see does not represent the difference in UV output

See that in a warming up mercury lamp : In the beginning it is pink because the phosphor glows brighter than the visible light from the arctube, so there is relatively high UV

I seen broken 125W mercury lamps keep going for many months... I know of one that does righ now and its ben like that for allmost a year, that one is in a posttop lantern with partially smashed bowl so it was still protected from direct contact with rain etc

Yes but I bet that the UV was terrible on the bowl (assuming that it was plastic).

It is, but here the sunlight can sometimes compete with the HID in the amount of damage....

The newer plastic bowls are more resistant to UV. I've seen some old bowls or buckets completely browned from years of exposure.

The newer plastic bowls are more resistant to UV. I've seen some old bowls or buckets completely browned from years of exposure.

Me too. I have also seen some old ones not brown at all. Weird.

Quote from: Solanaceae on June 03, 2015, 08:30:10 PM

The newer plastic bowls are more resistant to UV. I've seen some old bowls or buckets completely browned from years of exposure.

Me too. I have also seen some old ones not brown at all. Weird.

some of the older bowls were made of glass as well.

Quote from: flyoffacliff on June 03, 2015, 08:34:54 PM

Quote from: Solanaceae on June 03, 2015, 08:30:10 PM

The newer plastic bowls are more resistant to UV. I've seen some old bowls or buckets completely browned from years of exposure.

Me too. I have also seen some old ones not brown at all. Weird.

some of the older bowls were made of glass as well.

Oh, is there a way to tell by looking at it from a distance?

If you see it shimmering in the sunlight, on an older model streetlight, chances are it's glass.

Varies with additives in the plastic

Some additives are added to iumprove UV stability. The type and quantity define how stable "plastic" will be

Other additives (strength and color related) may change it in the other direection. One material where its seen well is PMMA (its not really a "normal" plastic like most others). It is often fairly resistant by itself in the clear form, but if it is white (with some additive), it tends to yellow