Here I came across a U-bent fluorescent lights that are both Mercury starved, still glowing with Argon discharged at the another building where I worked.
They looks much redder than most european T8 retrofits with krypton-argon buffer used to be (The european T8s have a pinkish white color when mercury straved).
If this is the actual color of these U tubes, probably these lamps have also neon in their buffer.
Dor123, I have seen pinkish white ones but those are the even more starved ones.....(even dimmer and redder) the dimmer they are, the redder they are.....that's what I've noticed.......those that are more slightly starved tend to be pinkish white like you said....
If the mercury straved lamp have pure argon buffer, it glows a bluish-violet color, as this is the color of the argon.
If the mercury straved lamp have krypton-argon buffer, it glows a pinkish white. I saw several mercury starved Tungsram 18W T8s that glowed pinkish white, when they were totally mercury straved.
If there is any red shade in the color of the buffer gas of the mercury straved lamps, this may caused by two reasons:
1. The lamp have neon in the gas filling.
2. If the lamp is a triphosphors warm-white (2700K) fluorescent lamp, usually the tripohsphors will continue to glow by the remaining UV radiation of the buffer gas and because the red component is the most prominent in that case, the color of the lamp will be redder.
In this case, it looks that there is a neon in the gas filling.
N Well think about it....when I see a MV lamp with a bad cap...It tends to be extremely dim.....and its reddish too....I mean I see MV start out pink......so I would think its the same case on this....I have seen some of those with some missing phosphor.....and they always are in bluish color, never seen one have reddish gases.....not saying you are wrong.....but I've seen 3500 K turn kinda reddish....
Bulb Freak: According to a PM from Max on LG, Max said to me that the F32T8, also have a krypton-argon mixture like the european 36W T8. But the reason why the F32T8 lamps can be operated from rapidstarts despite this, is because of their electrically conductive coating. When i posted this in the forum, Joe added that the OCV of the F32T8 rapidstarts is higher than that of the F40T12 rapidstarts. However perhaps there were some things that Max didn't knew.
I also thought initially that the F32T8 have the same gas as the F40T12.
The primery reason for the moving from argon to krypton in Europe, is simply because it is more energy efficient than argon. But because of its lower lamp voltage, when using the standard T12 design on an existing ballast, the wattage and light output are both lower than argon (Indeed, this is the reason why the 8ft 100W T12 have a lower light output than the 8ft 125W T12).
The problem was solved by reducing the diameter, involuntarily, from T12 to T8.
The US couldn't use the new design, because their fluorescent lighting relys on rapidstarts, so they had to be used another approach to increase the lamp efficiency, and the fact that they wanted to nevertheless use the T8 design and even design it to be operate on a rapidstart ballast, caused me to think that their T8s have different gas filling than the 36W T8.
Actually this is most likely a instant start ballast....I usually more often find the redder mercury starved ones on instant start more than the rapid start or programmed start....most of our rapid start tend to be T12s......T8s can't be put on a regular T12 rapid start...they flicker if you do that.......flicker wildly...
There is one thing I do noticed that the General Service Department uses Sylvania Quicktronic electronic ballast. It seems to have independent circuit for each bulb in these fixtures. The bottom line is that one bulb works while the other is burned out.
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The one ahead of my cubicle two lights had spectacular EOL show recently. Now both are not glowing at all.
Now I can't wait to see it all fail at my cubicle area before they order light bulb replacement from General Service department
Update! The light just ahead of my cubicle just has been replaced! The burned out bulbs were Sylvanina Octron 4100K FO32/741 and was made in Germany.
If this is the actual color of these U tubes, probably these lamps have also neon in their buffer.
If the mercury straved lamp have krypton-argon buffer, it glows a pinkish white. I saw several mercury starved Tungsram 18W T8s that glowed pinkish white, when they were totally mercury straved.
If there is any red shade in the color of the buffer gas of the mercury straved lamps, this may caused by two reasons:
1. The lamp have neon in the gas filling.
2. If the lamp is a triphosphors warm-white (2700K) fluorescent lamp, usually the tripohsphors will continue to glow by the remaining UV radiation of the buffer gas and because the red component is the most prominent in that case, the color of the lamp will be redder.
In this case, it looks that there is a neon in the gas filling.
I also thought initially that the F32T8 have the same gas as the F40T12.
The primery reason for the moving from argon to krypton in Europe, is simply because it is more energy efficient than argon. But because of its lower lamp voltage, when using the standard T12 design on an existing ballast, the wattage and light output are both lower than argon (Indeed, this is the reason why the 8ft 100W T12 have a lower light output than the 8ft 125W T12).
The problem was solved by reducing the diameter, involuntarily, from T12 to T8.
The US couldn't use the new design, because their fluorescent lighting relys on rapidstarts, so they had to be used another approach to increase the lamp efficiency, and the fact that they wanted to nevertheless use the T8 design and even design it to be operate on a rapidstart ballast, caused me to think that their T8s have different gas filling than the 36W T8.
I think most of us here already know about fill gases in fluoro lamps so there isn't a need to repeat it again and again.