818:, Volume 27, page 211 (June 1937): “Referring again to Table I, terms (21) and (22) represent names for units which the committee has voted to adopt. The decision was almost unanimous in the case of recommending talbot as a
186:
745:
recommend that photometric quantities be denoted with a subscript "v" (for "visual") to avoid confusion with radiometric or
872:
851:
841:
27:
75:
179:
815:
106:
714:
877:
366:
172:
742:
8:
730:
689:
655:
281:
59:
311:
113:
847:
807:
610:
560:
483:
443:
729:" are for length, time and luminous intensity respectively, not the symbols for the
228:
71:
42:
866:
819:
272:
83:
139:, proposed by the Committee on Colorimetry in 1937, correlates with the old
603:
288:
248:
125:
124:
The use of the symbol T for talbots conflicts with T as the symbol for the
110:
91:
79:
843:
Dictionary of
Scientific Units: Including dimensionless numbers and scales
812:
Colorimetry: Preliminary draft of a report on nomenclature and definitions
398:
344:
694:
498:
389:
148:
763:
761:
759:
351:
292:
846:(6th ed.). Springer Science & Business Media. p. 92.
756:
387:
source area. The candela per square metre is sometimes called the
332:
326:
105:). This name was coined in 1937 by the Committee on Colorimetry,
746:
87:
675:
Luminous efficacy normalized by the maximum possible efficacy
823:
152:
826:. The vote on lumerg as the psychophysical correlate of the
628:
622:
580:
574:
147:
in the same way that the lumen second correlates with the
827:
419:
413:
144:
140:
803:
801:
799:
751:
USA Standard Letter
Symbols for Illuminating Engineering
684:
32:
796:
707:
116:. The talbot is exactly equal to the lumen second:
864:
839:
180:
736:
650:Ratio of luminous flux to power consumption
383:Luminous flux per unit solid angle per unit
187:
173:
263:The lumen second is sometimes called the
97:The lumen second is sometimes called the
128:, the SI unit of magnetic flux density.
840:Jerrard, H. G.; McNeill, D. B. (2012).
865:
208:
204:
201:
198:
767:Alternative symbols sometimes seen:
13:
783:for luminous efficacy of a source.
713:The symbols in this column denote
16:SI derived unit of luminous energy
14:
889:
157:10 lumerg = 1 lm⋅s
416:(= lumen per square metre)
833:
306:Luminous energy per unit time
1:
790:
537:lumen second per cubic metre
329:(= lumen per steradian)
76:International System of Units
519:Time-integrated illuminance
7:
753:USAS Z7.1-1967, Y10.18-1967
10:
894:
816:Optical Society of America
602:Ratio of luminous flux to
107:Optical Society of America
749:quantities. For example:
679:
654:
609:
559:
523:
482:
442:
397:
350:
310:
271:
227:
222:
219:
216:
213:
78:(SI). It is based on the
48:
38:
26:
21:
873:Units of luminous energy
524:Luminous energy density
371:cd/m (= lm/(sr⋅m))
367:candela per square metre
167:SI photometry quantities
109:, in honor of the early
779:for luminous flux, and
743:Standards organizations
733:litre, tesla and joule.
658:, luminous coefficient
459:lumen per square metre
343:Luminous flux per unit
771:for luminous energy,
446:, luminous emittance
131:The photometric unit
830:was less unanimous.”
656:Luminous efficiency
195:
312:Luminous intensity
298:lm (= cd⋅sr)
164:
114:William Fox Talbot
814:. Journal of the
808:Loyd Ancile Jones
703:
702:
611:Luminous efficacy
561:Luminous efficacy
484:Luminous exposure
444:Luminous exitance
275:, luminous power
82:, the SI unit of
70:) is the unit of
56:
55:
885:
878:SI derived units
858:
857:
837:
831:
805:
784:
782:
778:
774:
770:
765:
754:
740:
734:
711:
663:
618:
570:
534:
495:
456:
410:
363:
323:
291:(= candela
285:
240:
196:
189:
182:
175:
168:
163:
158:
19:
18:
893:
892:
888:
887:
886:
884:
883:
882:
863:
862:
861:
854:
838:
834:
806:
797:
793:
788:
787:
780:
776:
772:
768:
766:
757:
741:
737:
712:
708:
699:
661:
616:
566:
563:(of radiation)
533:
527:
494:
488:
478:from a surface
455:
449:
409:
403:
362:
356:
335:(= lm/sr)
322:
316:
284:
278:
239:
233:
229:Luminous energy
206:
194:
193:
166:
156:
72:luminous energy
43:luminous energy
17:
12:
11:
5:
891:
881:
880:
875:
860:
859:
852:
832:
820:psychophysical
794:
792:
789:
786:
785:
755:
735:
705:
704:
701:
700:
698:
697:
692:
687:
681:
677:
676:
673:
668:
666:
664:
659:
652:
651:
648:
631:
625:
619:
614:
613:(of a source)
607:
606:
600:
583:
577:
571:
564:
557:
556:
554:
541:
538:
535:
531:
525:
521:
520:
517:
504:
501:
496:
492:
486:
480:
479:
474:Luminous flux
472:
463:
460:
457:
453:
447:
440:
439:
434:Luminous flux
432:
423:
422:(= lm/m)
417:
411:
407:
401:
395:
394:
381:
372:
369:
364:
360:
354:
348:
347:
341:
336:
330:
324:
320:
314:
308:
307:
304:
299:
296:
286:
280:
276:
269:
268:
261:
252:
246:
241:
237:
231:
225:
224:
221:
218:
215:
211:
210:
207:
203:
200:
192:
191:
184:
177:
169:
165:
122:
121:
54:
53:
50:
46:
45:
40:
36:
35:
30:
24:
23:
15:
9:
6:
4:
3:
2:
890:
879:
876:
874:
871:
870:
868:
855:
853:9789401122948
849:
845:
844:
836:
829:
825:
822:correlate of
821:
817:
813:
809:
804:
802:
800:
795:
764:
762:
760:
752:
748:
744:
739:
732:
728:
724:
720:
716:
710:
706:
696:
693:
691:
688:
686:
683:
682:
678:
674:
672:
669:
667:
665:
660:
657:
653:
649:
647:
643:
639:
635:
632:
630:
626:
624:
620:
615:
612:
608:
605:
601:
599:
595:
591:
587:
584:
582:
578:
576:
572:
569:
565:
562:
558:
555:
553:
549:
545:
542:
539:
536:
530:
526:
522:
518:
516:
512:
508:
505:
502:
500:
497:
491:
487:
485:
481:
477:
473:
471:
467:
464:
461:
458:
452:
448:
445:
441:
438:on a surface
437:
433:
431:
427:
424:
421:
418:
415:
412:
406:
402:
400:
396:
392:
391:
386:
382:
380:
376:
373:
370:
368:
365:
359:
355:
353:
349:
346:
342:
340:
337:
334:
331:
328:
325:
319:
315:
313:
309:
305:
303:
300:
297:
294:
290:
287:
283:
277:
274:
273:Luminous flux
270:
266:
262:
260:
256:
253:
250:
247:
245:
242:
236:
232:
230:
226:
212:
197:
190:
185:
183:
178:
176:
171:
170:
162:
160:
154:
150:
146:
142:
138:
134:
129:
127:
119:
118:
117:
115:
112:
108:
104:
100:
95:
93:
89:
85:
84:luminous flux
81:
77:
73:
69:
65:
61:
51:
47:
44:
41:
37:
34:
31:
29:
25:
20:
842:
835:
811:
750:
738:
726:
722:
718:
709:
670:
645:
641:
637:
633:
604:radiant flux
597:
593:
589:
585:
567:
551:
547:
543:
528:
514:
510:
506:
489:
475:
469:
465:
450:
435:
429:
425:
404:
388:
384:
378:
374:
357:
338:
317:
301:
264:
258:
254:
244:lumen second
243:
234:
161:
136:
132:
130:
123:
120:1 T = 1 lm⋅s
111:photographer
102:
98:
96:
92:SI base unit
67:
64:lumen second
63:
57:
39:Unit of
22:Lumen second
399:Illuminance
345:solid angle
149:radiometric
28:Unit system
867:Categories
791:References
715:dimensions
695:Radiometry
690:Photometry
680:See also:
621:lumen per
573:lumen per
499:lux second
155:, so that
86:, and the
60:photometry
385:projected
352:Luminance
293:steradian
205:Dimension
199:Quantity
94:of time.
436:incident
101:(symbol
725:" and "
540:lm⋅s/m
476:emitted
327:candela
223:Symbol
217:Symbol
137:lumberg
74:in the
850:
747:photon
265:talbot
209:Notes
133:lumerg
99:talbot
90:, the
88:second
62:, the
49:Symbol
824:joule
731:units
503:lx⋅s
462:lm/m
289:lumen
220:Name
214:Name
202:Unit
153:joule
151:unit
143:unit
126:tesla
80:lumen
848:ISBN
721:", "
623:watt
575:watt
68:lm⋅s
52:lm·s
828:erg
775:or
717:; "
627:lm/
579:lm/
414:lux
390:nit
251:⋅s
145:erg
141:CGS
135:or
58:In
869::
810:.
798:^
758:^
685:SI
420:lx
393:.
333:cd
295:)
267:.
249:lm
159:.
33:SI
856:.
781:ρ
777:F
773:P
769:W
727:J
723:T
719:L
671:1
662:V
646:J
644:⋅
642:T
640:⋅
638:L
636:⋅
634:M
629:W
617:η
598:J
596:⋅
594:T
592:⋅
590:L
588:⋅
586:M
581:W
568:K
552:J
550:⋅
548:T
546:⋅
544:L
532:v
529:ω
515:J
513:⋅
511:T
509:⋅
507:L
493:v
490:H
470:J
468:⋅
466:L
454:v
451:M
430:J
428:⋅
426:L
408:v
405:E
379:J
377:⋅
375:L
361:v
358:L
339:J
321:v
318:I
302:J
282:v
279:Φ
259:J
257:⋅
255:T
238:v
235:Q
188:e
181:t
174:v
103:T
66:(
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