Lamp: 100 watt A19, 120V, clear, Sylvania, filament CC-8, lamp vertical
Updated 4/27/2020.
------------------------------------------------------------------------
Volts .5 1 1.5 2 3 4.5 6 9 12 15 18 24 30 36 42 48 60 72 84 96 108 120 132 144 160
Amps .047 .083 .108 .126 .152 .177 .196 .227 .254 .280 .304 .350 .394 .433 .470 .505 .571 .631 .688 .740 .788 .834 .878 .921 .976
% Volts .4167 .8333 1.25 1.667 2.5 3.75 5 7.5 10 12.5 15 20 25 30 35 40 50 60 70 80 90 100 110 120 133.3
% Amps 5.63 9.95 12.95 15.1 18.2 21.2 23.5 27.2 30.5 33.6 36.5 42.0 47.2 51.9 56.4 60.6 68.5 75.7 82.5 88.7 94.5 100 105.3 110.4 117
log(i/I)/ .525 .482 .466 .461 .462 .472 .483 .502 .516 .525 .532 .539 .541 .544 .546 .547 .547 .546 .540 .536 .538 --- .539 .544 .547
log(v/120)
color temp. K (2011 determination) ~800 ~977 1125 1245 1355 1528 1672 1800 1913 2015 2195 2360 2500 2635 2760 2875 2985 3085 3210
log(ct/CT)/ (2011 determination) .43 .418 .408 .403 .397 .393 .391 .389 .388 .388 .388 .388 ~.39 ~.39 ~.39 ---- ~.39 .388 .383
log(v/120)
color temp. K (2020 determination) 1815 1935 2037 2215 2372 2515 2644 2763 2875 2980 3080
log(ct/CT)/ (2020 determination) .382 .377 .376 .376 .376 .376 .376 .376 ---- .376 .376
log(v/120)
~1.25E-4
lumens (approximately, 2011) ~8 E-7 ~.0033~.025 ~.12 ~.96 ~3.7 ~10.6 24 46 125 268 483 798 1218 1750 2405 3160 4310
log(lu/LU)/ 7.18 6.35 5.72 5.35 5.05 4.66 4.44 4.24 4.09 3.97 3.8 3.68 3.61 3.52 3.44 ---- 3.33 3.24 3.13
log(v/120) (approximately!)
lumens (approximately, 2020) 11.5 26.5 51 133 281 507 820 1235 1750 2375 3115
log(lu/LU)/ 4.17 3.97 3.86 3.71 3.58 3.47 3.39 3.31 ---- 3.20 3.16
log(v/120) (approximately!)
Lamp: 25 watt A19, 120V, clear, GE, filament CC-6, lamp vertical
------------------------------------------------------------------------
Volts .5 1 1.5 2 3 4.5 6 9 12 15 18 24 30 36 42 48 60 72 84 96 108 120 132 144 160
Amps .011 .0205 .0285 .035 .0455 .056 .0635 .073 .0795 .085 .090 .0995 .1075 .116 .124 .131 .146 .1595 .1725 .1845 .1955 .2065 .217 .2275 .240
% Volts .4167 .8333 1.25 1.667 2.5 3.75 5 7.5 10 12.5 15 20 25 30 35 40 50 60 70 80 90 100 110 120 133.3
% Amps 5.33 9.93 13.8 16.95 22.0 27.1 30.75 35.35 38.5 41.1 43.6 48.2 52.1 56.2 60.0 63.4 70.7 77.2 83.5 89.3 94.7 100 105.1 110.2 116.2
log(i/I)/ .535 .482 .452 .434 .410 .398 .394 .401 .415 .428 .438 .453 .470 .479 .487 .497 .500 .507 .51 .51 .51-.52 --- .52 .52-.53 .52-.53
log(v/120)
color temp. K 2550
Lumens (approximately!) 210
Lamp: 25 watt T10, 120V, clear, GE, filament C-8, lamp vertical
------------------------------------------------------------------------
Volts .5 1 1.5 2 3 4.5 6 9 12 15 18 24 30 36 42 48 60 72 84 96 108 120 132 144 160
Amps .008 .012 .015 .018 .023 .029 .0345 .0445 .053 .061 .068 .0815 .0935 .1045 .1145 .124 .1425 .1585 .1735 .188 .201 .214 .226 .238 .252
% Volts .4167 .8333 1.25 1.667 2.5 3.75 5 7.5 10 12.5 15 20 25 30 35 40 50 60 70 80 90 100 110 120 133.3
% Amps 3.74 5.61 7.00 8.41 10.75 13.6 16.1 20.8 24.8 28.5 31.8 38.1 43.7 48.8 53.5 57.9 66.6 74.1 81.1 87.9 93.9 100 105.6 111.2 117.8
log(i/I)/ .600 .602 .607 .605 .605 .608 .610 .606 .605 .604 .604 .600 .597 .596 .596 .596 .586 .587 .587 ~.58 .58-.59 --- ~.58 .58 .57
log(v/120)
color temp. K 2550
Lumens (approximately!) 260
In addition, plenty of interpolation was done.
Color temperature at full voltage for 100 watt 120V 750 hour A19 was assumed to be 2875 K because of mention of around 2875-2880 K in the IES Handbook. Kodak mentions 2865 K, but that dates back to when Standard Illuminant A was 2848 K, since redefined to 2854 K as a result of updating a constant in the blackbody formula.
Color temperature of coiled-coil filament in gas-filled bulb was assumed to be
halfway between the actual temperature and the color temperature of a straight
tungsten wire in vacuum at the same actual temperature according to the table.
Actual temperature at voltages other than full voltage were worked from
filament resistance as a function of actual temperature according to the
above "Properties of Tungsten" table.
Color temperature in 2020: updated 4/27/2020
Color temperature was determined at 120 volts and 60 volts with a spectrometer.
As the voltage was changed from 120 to 60 volts, the color temperature was found
to have changed proportionately with voltage to the .376 power. At voltages from
48 to 144 volts, color temperature was interpolated or extrapolated as being
proportional to voltage to the .376 power.
Color temperature at 36 volts was measured with a spectrometer, at 42 volts was revised to an interpolation on 4/27/2020.
Color temperature of other lamps at full voltage largely come from color matching them to a 100 watt 120V A19 that is powered by an adjustable voltage power supply and use of my 2011 data for the above 100 watt lamp.
It is to be noted that the temperature is not completely uniform throughout the filament. It is also to be noted that the temperature profile of the filament varies with temperature since heat loss from radiation and conduction vary differently with temperature. As a result, color temperature and lumen figures are only roughly approximate, especially at more extreme voltages.
Lumens:
Color temperature was plugged into a homebrew BASIC program that has the
blackbody function and the photopic function. "Color emissivity" (ratio of
brightness of a given incandescent surface to a blackbody surface at the same
color temperature) for a coiled-coil filament in a gas-filled bulb was assumed
to be the square root of that shown in the "Properties of Tungsten" table
for a straight wire in vacuum, for a given actual temperature. Color emissivity
varies slightly inversely with temperature. This permits working of lumens at
various filament temperature given color and assumed actual temperature and
manufacturer's stated lumens at full voltage.
Brightness according to the brightness column in the "Properties of Tungsten"
table varies even slightly more drastically with temperature than according to
my homebrew BASIC program. UPDATE 4/26/2020: A light meter will soon be used to
verify my determinations of how light output varies with voltage.
For Osram's version of the FEL lamp, updated 4/23/2020, more updating stated on 4/26/2020 as happening soon is done by exponential interpolation 11/7/2022.
Volts Color temp K Lumens 20 ~ 1615 (updated from ~1600) ~ 14 (updated from ~11) 24 ~ 1735 (updated 11/7/2022) ~ 39 - 40 (updated 11/7/2022) 27 ~ 1820 (updated from ~1800) ~ 76 (updated from ~63) 28 ~ 1845 (updated 11/7/2022) ~ 90 - 91 (updated 11/7/2022) 36 ~ 2025 (updated from ~2000) ~ 300 (updated from ~248) 48 ~ 2275 (updated 11/7/2022) ~ 1,100 (updated 11/7/2022) 60 ~ 2490 (new line 4/23/2020) ~ 2,990 (new line 4/23/2020) 120 ~ 3200 ~ 27,500
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