Got the replacement lamp for my street light today. This is the old burned out lamp. When Metal Halide lamps burn out, the arc tube explodes.
Yes in corrective maintenance mode!
If the lamp is used past its life expectancy where its color temp drifts way warm and efficacy drops considerably, the arc tube temperature and pressure increases. Bulges form and it can rupture suddenly extinguishing the light. If the lamps are used in 24/7 operation their replacement cycle with good maintenance practice should be annually scheduled.
Mercury vapor lamps are quite tolerant of being operated way past their efficient lifetimes and be seen casting a dim green-ish glow producing single digit lumens per watt! In areas experiencing severe weather or where vandals may toss things at them occasionally one will find them still operating with the envelope missing. This is quite dangerous as an unprotected mercury tube produces copious amounts of UV-C that will burn skin and damage eyes. If they're up high no worries. Some feature a resistor looking device that will burn out in the presence of ambient air (>16% O2) so this does not happen. If the diffuser comes off in severe winds and rain strikes the envelope the sudden thermal shock usually causes it to shatter and the arc tube continues to operate...
HPS lamps have an interesting failure mode. The operating voltage to maintain a stable arc increases beyond the capability of the ballast/supply and will extinguish the lamp. When it cools down it will restrike, warm to operating temperature and output until it goes out. This is a positive signal of end of life for the lamp. A lot of HPS roadway fixtures can be found operating in this manner as well.
LPS lamps are quite interesting. They have near 0 CRI and are very, very yellow. Their efficacy can reach in the upper 100s of lumens/watt which makes them good for lighting large open areas where color rendering is of secondary concern (airports, railways, etc.) When cold, there is typically enough solidified pure sodium metal to produce some small fireworks if said tube is broken and tossed in a body of water.
Yes in corrective maintenance mode!
If the lamp is used past its life expectancy where its color temp drifts way warm and efficacy drops considerably, the arc tube temperature and pressure increases. Bulges form and it can rupture suddenly extinguishing the light. If the lamps are used in 24/7 operation their replacement cycle with good maintenance practice should be annually scheduled.
Mercury vapor lamps are quite tolerant of being operated way past their efficient lifetimes and be seen casting a dim green-ish glow producing single digit lumens per watt! In areas experiencing severe weather or where vandals may toss things at them occasionally one will find them still operating with the envelope missing. This is quite dangerous as an unprotected mercury tube produces copious amounts of UV-C that will burn skin and damage eyes. If they're up high no worries. Some feature a resistor looking device that will burn out in the presence of ambient air (>16% O2) so this does not happen. If the diffuser comes off in severe winds and rain strikes the envelope the sudden thermal shock usually causes it to shatter and the arc tube continues to operate...
HPS lamps have an interesting failure mode. The operating voltage to maintain a stable arc increases beyond the capability of the ballast/supply and will extinguish the lamp. When it cools down it will restrike, warm to operating temperature and output until it goes out. This is a positive signal of end of life for the lamp. A lot of HPS roadway fixtures can be found operating in this manner as well.
LPS lamps are quite interesting. They have near 0 CRI and are very, very yellow. Their efficacy can reach in the upper 100s of lumens/watt which makes them good for lighting large open areas where color rendering is of secondary concern (airports, railways, etc.) When cold, there is typically enough solidified pure sodium metal to produce some small fireworks if said tube is broken and tossed in a body of water.
With a cat familar and a broomstick.I still suspect you are a real witch and walk around with a force field
ni
Making some chicken fingers nef.
Just prepackaged ones, probably not that good for me, but meh. Probably better than ordering something.
I just had to be the tough guy.
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