Re: The insane progress nobody is talking about

On Mon, 01 Jul 2024 17:26:15 GMT, scott@slp53.sl.home (Scott Lurndal)
wrote:

Paul S Person <psperson@old.netcom.invalid> writes:

On Mon, 1 Jul 2024 16:11:11 +0100, Robert Carnegie

>

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BTW, the two main bulbs (one now an LED, the other a CFL that has been
going for about 3.5 years per my records) are on during the day and
during the night (respectively). So between them, one or the other is
always on. So that is an average of 12 hours/day. Since 12 =3D 3 x 4,
7yrs/(12 hrs/3hrs/day) =3D 7/4 hrs =3D 1.75 years in realistic use. The
CFL, at least, is doing much better. And the LED is meeting
expectations.
>
If they want their claims to be valid, this is what they need to do:

>
https://energy.gov/sites/prod/files/2017/04/f34/lsrc_colorshift_apr2017.pdf
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   LED packages rarely fail abruptly (i.e., instantaneously stop emittin
   light), but rather experience parametric failures such as degradation
   or shifts in luminous flux, color point (chromaticity coordinates),
   color rendering index (CRI), or efficacy. Of these parametric shifts,
   lumen depreciation has received the most attention because it was
   previously thought that the degradation of lumen output of the LED
   source itself would be the prime determinant of lifetime for the
   completed product. While it is now understood that this is not
   the case, lumen maintenance is still used as a proxy for LED lamp or
   luminaire lifetime ratings, largely due to the availability of
   standardized methods for measuring and projecting LED package lumen depreciation.
>
>
   Many researchers have put a great deal of effort into devising a
   way to project the time at which L70 will be reached for an LED
   package in a luminaire, and IES has documented a forecasting procedure,
   IES TM-21,3 which uses the LM-80 test data for the lumen maintenance
   projections (a minimum of 6,000 hours of test data is required). The
   LM-80 data (luminous flux vs. test hours) for the LEDs tested is averaged
   and an exponential curve fit is applied to the data; the results of th
   curve fit are used to calculate a lumen maintenance lifetime projection.
   This technical memorandum stipulates that any projection may
   not exceed a set multiple (depending on sample size statistics) of
   the actual hours of LM-80 testing data taken, which helps avoid exaggerated claims.
>
   It should be noted that LM-80 measurements are taken with the LED packages
   operating continuously in a temperature-controlled environment, where the
   solder point and ambient air temperature are at equilibrium. This does not
   necessarily reflect real-world operating conditions, so there may not be a
   perfect match between predictions based on laboratory test results and
   practical experiences with lamps and luminaires in the field. Nevertheless,
   lumen maintenance projections can help sophisticated users compare products,
   as long as their limitations are properly understood.
>
   When LEDs are installed in a luminaire or system, there are many
   additional factors that can affect the rate of lumen depreciation
   or the likelihood of catastrophic failure. These include temperature
   extremes, humidity, chemical incursion, voltage or current fluctuations,
   failure of the driver or other electrical components, damage or degradation
   of the encapsulant material covering the LEDs, damage to the interconnections
   between the LEDs and the fixture, degradation of the phosphors, and yellowing
   of the optics. In addition, abrupt semi-random short-term failures may be
   observed due to assembly, material, or design defects. More information on
   system level lifetime can be found in LSRC's LED
   Luminaire Lifetime: Recommendations for Testing and Reporting.
>
Much more useful information in the aforecited URL.

No amount of weasel-words and bumpf can serve to do anything but
confirm my position.

And they are venturing near the "10 million unknown and unknowable
causes" cited by idiots trying to prove that the Universe is fully
deterministic. Which are an atheist's replacement for the hordes of
teeny-tiny devils and angels once believed to be endlessly flitting
about us and influencing our decisions. This is not credible in any
form. Well, quantum mechanics excepted, perhaps.
--
"Here lies the Tuscan poet Aretino,
Who evil spoke of everyone but God,
Giving as his excuse, 'I never knew him.'"