What will happen to MH and HPS before the end of their lives? « on: February 05, 2022, 09:08:52 PM » Author: bulb_tester2009
I know MH The arc will turn green at the end of life, the arc tube will bulge, and the arc tube will crack after a long time of bulge. When the arc tube cracks, MH will die. But I don't know what will happen to  HPSCan you tell me?
« Last Edit: February 05, 2022, 09:11:53 PM by bulb_tester2009 »		Logged

My interest in lights began when I was a child
One of the few Chinese users in LG

Lamp bases in China:E12(CES) E14(SES) B22d(BC) E27(ES) E40(GES)
Poor quality lamps in my collection are prohibited. Most of them have been used for my destructive experiments and ballast tests.

	Re: What will happen to MH and HPS before the end of their lives? « Reply #1 on: February 05, 2022, 11:57:07 PM » Author: bulb_tester2009
Will the arctube crack?
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My interest in lights began when I was a child
One of the few Chinese users in LG

Lamp bases in China:E12(CES) E14(SES) B22d(BC) E27(ES) E40(GES)
Poor quality lamps in my collection are prohibited. Most of them have been used for my destructive experiments and ballast tests.

	Re: What will happen to MH and HPS before the end of their lives? « Reply #2 on: February 06, 2022, 04:16:21 AM » Author: AngryHorse
Only a small percentage of them leak, with HPS, the pressure usually just goes through the roof until their a bright mercury green colour on start up, and then constantly cycle within a very short period of being on.
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	Re: What will happen to MH and HPS before the end of their lives? « Reply #3 on: February 06, 2022, 04:25:51 AM » Author: Medved
The arctube may crack (some defect or when exposed to some vibration stress,...), but with HPS it is nothing violent, the pressure there is just way too low and the tube narrow (so not that big forces involved). Usually as the HPS arctube blackens over time, it starts to overheat. And because HPS are saturated vapor lamps, overheating leads to the lamp cycling. But if the arctube leaks and so ignite the discharge in the outer bulb, the outer may shatter and cause hot glass and metal showering down.
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	Re: What will happen to MH and HPS before the end of their lives? « Reply #4 on: February 06, 2022, 08:38:29 PM » Author: bulb_tester2009
I have seen the explosion of MH. The arctube explosion did not break through the shell, but left black marks in the shell.
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My interest in lights began when I was a child
One of the few Chinese users in LG

Lamp bases in China:E12(CES) E14(SES) B22d(BC) E27(ES) E40(GES)
Poor quality lamps in my collection are prohibited. Most of them have been used for my destructive experiments and ballast tests.