Light bulb reliability

[ban-all-sheds]

Well 3000K from a good manufacturer (megaman), is advertised as 'Warm White' but it ain't!

Actually, it is.

And it's about the same as halogen lamps, and a little whiter than non-halogen incandescents.

But anyway - don't buy "warm white" then, if you don't like it, buy extra-warm white.

Or look for actual numbers, as there can be overlap in descriptions - go for 2700° or colour code 827.

 

[scousespark]

Having googled for an answer, the industry appear to have standardised on a measure called 'Average Rated Lamp Life' and is the point in hours were half the lamps in a sample group have failed.

BTW JohnW, I had missed a smiley off my post.

 

[ban-all-sheds]

1) A 15,000 hour life does not mean it's the average - it means that by 15,000 hours half will have failed.

 

[scousespark]

I was actually posting in response to an earlier question as to what the industry used as the measuement and the definition was just there to clarify.

 

[JohnW2]

Having googled for an answer, the industry appear to have standardised on a measure called 'Average Rated Lamp Life' and is the point in hours were half the lamps in a sample group have failed.

Thanks, that's very interesting - so BAS was right that the figures are median survival times. That's certainly at variance with the usual practice of the electrical and electronics (and many other) industries, who generally quote 'MTBF' figures for most manufactured products.

BTW JohnW, I had missed a smiley off my post.

Fair enough. In any event, my response probably didn't do any harm, since there may well have been others who were thinking like you (without the smiley!).

Kind Regards, John.

 

[ban-all-sheds]

Dear all,
I have 6 Megaman bulbs in my kitchen. (CFL - Reflector - R80 - code 616897)

If you would consider replacing the fittings, something like this would fit the bill:



Or if you want LEDs,the Thorn BaseLED looks good on paper:

http://www.thornlighting.co.uk/download/Base_LED_Brochure.pdf

http://www.thornlighting.co.uk/PDB/Ressource/teaser/E2/TLG_BaseLED.pdf

http://www.thornlighting.co.uk/object/PDF/datasheet.aspx?CompanyID=7&GroupID=12650&CL=E2&CC=GB


Not cheap, though...

 

[peteuk]

Thanks for the examples Ban-all-sheds.
Will investigate further if I have more failures.
Thought people may be interested in the reply from Megaman which answers and confirms some of the questions / points raised above:

"I can assure you that every batch of lamps Megaman manufactures is rigorously tested and the results are logged and analysed.
This testing denotes any issues with lamp life; our lamp life is calculated at the point when 50% of the lamps are extinguished, even though the other 50% of the lamps are still working well. To put this into perspective, some of the other lamp manufacturers wait for 100% of lamps to be extinguished before declaring the lamp life of the product they are selling.

Regretfully lamps do tend to be the first suspect when an issue occurs but there are many other contributory factors to the demise of the lamp life. Factors include although not exhaustive; operating temperature, switching cycle, the fitting itself i.e.; the type, the lamp holder or the wiring, etc.
Our products are very delicate and could become damaged due to transit, handling or other circumstances beyond our control. In these cases, where our lamps are covered under our 18 month warranty we ask that you return the lamp to the original point of purchase."

For info: B&Q said they replace up to 12 months old

 

[JohnW2]

I can assure you that every batch of lamps Megaman manufactures is rigorously tested and the results are logged and analysed. This testing denotes any issues with lamp life;

I have to say that I find it very hard to see what testing of production batches would give much insight into likely life of lamps in the batch.

our lamp life is calculated at the point when 50% of the lamps are extinguished, even though the other 50% of the lamps are still working well. To put this into perspective, some of the other lamp manufacturers wait for 100% of lamps to be extinguished before declaring the lamp life of the product they are selling.

If they are making a useful point here, I'm at a complete loss to understand what it is! If (per all the discussions here) the lamp life they're quoting is the 'median' (i.e. the time taken until 50% are dead) they obviously don't need to continue the test until "100% are extingusihed" (which could take many years!), and I don't understand why 'other lamp manufacturers' should do so either - and it's particularly odd that they appear to be implying that their method (which sounds fine) is in some way 'better'. One can't help but feel that this was probably not written by a 'technical p[erson'!

Kind Regards, John.