Why do CMHs have blue-tinted glass? « on: Today at 04:11:53 AM » Author: SoxFtw
I bought some ceramic metal halides: Philips CDM-T 70W/942 Philips CDM-T 70W/830 Osram HCI-T 70W/942 And all of them have a visibly blue tint on the glass body that is visible even when not powered on. It makes mild difference to the lamp color when warming up and even at full power it's almost glowing. Is there any reason for this or is it part of manufacturing process?
« Last Edit: Today at 04:14:52 AM by SoxFtw »		Logged

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	Re: Why do CMHs have blue-tinted glass? « Reply #1 on: Today at 04:47:05 AM » Author: dor123
The blue glow that you see on the outer jacket of compact MH lamps is the UV dopants that are used to filter the UV radiation, since the outer jacket is made from quartz.
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	Re: Why do CMHs have blue-tinted glass? « Reply #2 on: Today at 05:31:51 AM » Author: SoxFtw
Yes they are G12 single ended lamps, I didn't know the outer jacket wasn't made with UV-blocking borosilicate type glass. Thanks for explaining it.
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	Re: Why do CMHs have blue-tinted glass? « Reply #3 on: Today at 06:47:26 AM » Author: dor123
The R7s ones are also have quartz jackets, so they need UV dopants. Except my Osram HQI-TS 70W/WDL from 1988, all my R7s MH lamps have blue glowing outer jackets. Even my Osram NAV-TS 70W Super 4Y HPS lamp have this glow during the xenon phase.
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I"m don't speak English well, and rely on online translating to write in this site.
Please forgive me if my choice of my words looks like offensive, while that isn't my intention.

I only working with the international date format (dd.mm.yyyy).

I lives in Israel, which is a 220-240V, 50hz country.