Re: "Full-spectrum" article on Wikipedia

"Victor Roberts" <xxx@xxxxxxxxxxxxxxxxxxxxx> wrote in message
news:avjb63h91aafttkq0b9p260ps600euk699@xxxxxxxxxx
[snip]

Your formula seems correct. How far off are your
calculations? can you post a couple of results?

Except for incandescent lamps, I don't see that Table 1 of
the LRC publications gives you enough information about the
spectrum of the lamps in question to make an accurate
calculation.

Vic,

here's what I used and what I've got:

I've used:

FSI = sum((1 - i_k/i_max)^2, k=380..700)/(700-380), where i_max is the
maximum on the measured spectrum and i_k is the intensity at
wavelength k. I've gone only as far as 700, since I don't use the
additional 30nms.

Here's what I've got for my lamps, using the same abbreviation as on
my Engineering document, with the rating in parens:

TH 0.312 (2)
D 0.024 (1)
CFL27K 0.98 (10)
CFL4K 0.965 (7)
HPM 0.988 (14)
HPMC 0.983 (11)
BL 0.974 (9)
MHE 0.987 (13)
MHA 0.968 (8)
MHD 0.974 (9)
PLANT 0.984 (12)
BLAU 0.991 (15)
GRUN 0.995 (16)
DIAZ1 0.949 (5)
DIAZ2 0.996 (17)
LPS 0.997 (18)
HPS 0.922 (4)
FLASH 0.858 (3)
HPX 0.963 (6)

In general the ordering appears consistent. In my opinion two lamps
are dissonant: HPS and HPX. HPS should not be that high in the list
and HPX should be higher. The HPS discrepancy can be explained: It's
probably my approximation of the spectrum using Lorenztians which
gives too much attention to the D wings, thus filling the spectrum
some. The HPX is also somewhat faulty, as it was gotten by balancing
Becker's online spectrum, and the red component is too strong.
Otherwise the number gives roughly the percentage of how "empty" the
spectrum is.

A second comment on the HPS: If one increases the pressure some more,
one gets a 2500K HPS "white" sodium lamp, which is close to an
incandescent, so perhaps the calculation for the HPS is not that
faulty afterall. I don't know.

I am not sure whether I will pursue this avenue yet, because otherwise
my spectra ARE balanced, and I don't want to do guesswork with the FSI
formula. If the authors wanted this to be a serious calculation they
should have included the exact mathematical formula used.

--
Vic Roberts
http://www.RobertsResearchInc.com
--
I.N. Galidakis --- http://ioannis.virtualcomposer2000.com/
----------------------------------------------------------
"There's ALWAYS a mistake somewhere"

.

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