mh bulb help

R_Hudson · 08/08/2008, 04:29 PM

ok so I bought a generic halide bulb off ebay for 20 bucks I know shame on me but anyways it came in the mail today and while checking to see if it was broke I noticed there is no filament in the center and there are small black bubbles on the glass. looks like it might be a used bulb that's burned out. I havnt tried to fire it up yet. is this a normal thing if it helps its a 20k 70w from light spectrum enterprises

PaulErik · 08/08/2008, 05:54 PM

Halide bulbs use an electrical discharge (arc) between to electrodes. They do not have a filament. The bubbles you see are most likely the halides and mercury inside the inner bulb (arc tube). The halides and mercury will vaporize once the lamp warms up. At room temperature they will condensate on the glass.

08/08/2008, 04:29 PM	#1
R_Hudson Just having fun Join Date: Oct 2006 Location: Tulsa, Ok. Posts: 990	mh bulb help ok so I bought a generic halide bulb off ebay for 20 bucks I know shame on me but anyways it came in the mail today and while checking to see if it was broke I noticed there is no filament in the center and there are small black bubbles on the glass. looks like it might be a used bulb that's burned out. I havnt tried to fire it up yet. is this a normal thing if it helps its a 20k 70w from light spectrum enterprises

08/08/2008, 05:54 PM	#2
PaulErik Premium Member Join Date: Dec 2000 Location: North Charleston, SC Posts: 1,703	Halide bulbs use an electrical discharge (arc) between to electrodes. They do not have a filament. The bubbles you see are most likely the halides and mercury inside the inner bulb (arc tube). The halides and mercury will vaporize once the lamp warms up. At room temperature they will condensate on the glass.