blackening of tubes

[Ankit Gupta]

why tubes get blackned at the ends after some times and which substance does it ?

 

[John Cuthber]

What sort of tubes?

http://en.wikipedia.org/wiki/Tube

[Phi for All]

If you're talking about florescent tubes, the blackening on the ends is caused by a loss of metal from the filaments due to improper heating over time. Modern quick start ballasts turn the light on more quickly at the expense of a proper heating cycle. Once the filaments have heated to the right temperature, this loss is minimized.

 

Strike another blow for convenience. Older tubes took longer to reach full light but lasted longer. Modern ones start up more quickly but burn out faster, so you spend more. My advice is to start using LEDs. As a matter of fact, I start working for my new client tomorrow and they just happen to make LED tubes that can be retrofit into florescent fixtures.

 

Wow, I really hope you aren't talking about test tubes.

[dimreepr]

The tightrope of advertising is a tricky rope to walk; nice footwork . That being said I am interested in the tubes you mention any links?

[Phi for All]

 

The tightrope of advertising is a tricky rope to walk; nice footwork . That being said I am interested in the tubes you mention any links?

 

I'll have to get back to you on that, once I determine how much info the company wants me giving out and how I can do so and still maintain my anonymity.

[Ankit Gupta]

i dont think so how can a metal loss make its surface black , my brother told that it can cause due to high potential difference b/n both ends and i think it is related to some rxn of zinc sulphide from which its white inner surface is made of ?

[Phi for All]

i dont think so how can a metal loss make its surface black , my brother told that it can cause due to high potential difference b/n both ends and i think it is related to some rxn of zinc sulphide from which its white inner surface is made of ?

 

Here's a study I found... illuminating:

http://www.cosine.co.za/Black%20End%20Rings%20on%20Fluorescent%20lamps.pdf

[Ankit Gupta]

thanks it is really nice and easy to understand

[Ankit Gupta]

what is the difference between in a CFL and a tube (i mean working) ?

[Phi for All]

what is the difference between in a CFL and a tube (i mean working) ?

 

The CFL is meant to replace old incandescent bulbs of varying types and sizes with fluorescent technology. They go into the standard round hole fixtures with screw-in or bayonet type bases. The tubes go into specific luminaires designed to accommodate them, usually in combinations of 2, 3 or 4 tubes per fixture, with lengths from 1 foot to 8 feet. The tubes provide a more even lighting where continuity is important (usually in commercial buildings).

 

All fluorescent bulbs/tubes are much more energy efficient and have better longevity than incandescents (incandescent bulbs use about 95% of their energy in non-visible spectrums, mostly IR as heat), but they contain mercury, they still use low-pressure glass casings which can shatter, they take time to come to full brightness, they can't be used with rheostats.

 

Personally, I think the CFL is an attempt to use existing manufacturing processes to reduce energy expenditures and get the best return on the investments made in the technology. IMO, it's better to leap right over the latest fluorescent technology and go straight to LED lighting. Instead of tubes fixed in ceiling troffers that illuminate in 360 degrees and have to be reflected, LED tubes can be directed just where you want them. The visible light spectrum can be precisely tuned (I've seen LED lights that use only the red and blue spectrums that plants use, perfect for hydroponic greenhouses). LEDs use much less electricity, you can get them with no harmful chemicals, and plastic casings that resist breakage.

[Ankit Gupta]

thanks for telling it but i mean CFL and fluorescent tube

[Phi for All]

thanks for telling it but i mean CFL and fluorescent tube

 

The first paragraph of my last post covered the basic difference. CFLs are mainly to replace incandescent bulbs with fluorescent technology, in fixtures designed for incandescent bulbs (usually having round sockets). Did you need more than that?

[Ankit Gupta]

ok thanks

[Ankit Gupta]

what is the use of starter and chawk in tube