which fluorescent bulb to replace with?

[cbarrnospam]

A 48" fluourescent kitchen light bulb died. Has a Sylvania "Super Saver F40ww/ss" bulb, also labeled "Rapid Start

34W" with another hard-to-read vertical label with E, 0 and 4.

a little over 15 yrs. old.

I would like to replace it with a "Daylight" spectrum bulb. Local Ace Hardware has this but it says "40 W" and I wonder if mine is actually 34W ? Box: GE Ecolux F40T12 ( I know that T12 means 1" diam. - which matches) label on glass: F40C50-ECO Chroma 50 40W USA

I see no other writing on outside of the existing bulb or the lamp fixture.

If I open it up and read the ballast label - what is meaningful on that? The fixutre is by "Lampi."

[RBM]

T12 is 12-eighths of an inch. Your fixture uses 34 watt lamps which used to be 40 watt, as opposed to T8-32 watt lamps

[cbarrnospam]

Right. The ballast (robertson RN1490P) - says "for (1) F30T12 30W, (1) F40T12 40W, (1) F40T12 34W, (1) FC12T9 32W" So - I think it *looks like* I can put in this GE Chroma 50 40w bulb . . .

RBM (remove this) wrote:

[Don Klipstein]

T12 is 1.5 inch diameter, which is very common.

I did see your next post about what the ballast said. It appears to me that the ballast is for 1.5 inch diameter "lamps" (bulbs) as opposed to the 1 inch diameter T8 32-watt ones.

MEANWHILE, I have plenty of comments on color/spectrum!

If what you want is a replacement for "Chroma 50", then the Philips "Natural Sunshine" available at Home Depot should be close enough and should not be in any way a disappointment! Just keep in mind that both of these as well as other "broad spectrum" types ("Deluxe Cool White" and the various equivalents, improvements, and fine-tunings thereof including versions tuned to color temperatures in the

5000-6000 Kelvin range or higher) have light output less than the "full" available from 4-foot fluorescents!

I have my own favorites here! The color rendering index is only 82, but the color distortions are majority towards directions of "brighter and more vivid", while most other fluorescents do the opposite. Furthermore, these lamps with CRI of 82 or slightly more have no compromise in light output. These are the higher of the two color rendering index grades of triphosphor fluorescents. Philips makes ones in T12 sizes with the name "Ultralume". Triphosphor in general and "Ultralume" specifically come in different colors noted mainly by "color temperature" numbers:

3000 or 30 - "warm white shade" roughly incandescent approximation 3500 or 35 - "whiter warm white" that I really like for home use 4100 or 41 - "cool white"/"regular white" shade, like that of "average sunlight" (my words), but better for colors than "old tech cool white" 5000 or 50 - "noontime tropical sunlight" icy cold pure white, like "Chroma 50" and Philips "Natural Sunshine"

Keep in mind that "cooler" (higher color temperature) colors 4100K or higher color temperature can cause a "dreary gray" effect unless you achieve the bright illumination levels (roughly 100-plus footcandles,

1100-plus lux) typically achieved in classrooms and offices. As a result, my favorite for most home use is 3500K, even if you want something whiter than incandescent (roughly 2700-2900 K).

- Don Klipstein ( [e-mail])