F 20W/25 (GE)

Тип:  F 20W/25  
Страна происхождения: 
Дата выпуска:  2000...2009

Товарищ отдал как перегоревшую, а оказалась рабочая. Редкий тип. Выпускалась на Тунгсраме, отличается только логотипом.

Из коллекции Ikarus280. Добавлено: пн, 24.04.23, 22:54



Ну нет, у ЛЕ Ra=85, а тут всего лишь 70.

откуда данные? измерение? у ЛЕ не может быть Ra-85 потому что ЛЕЦ имеет более 80. Не могу найти литературу но точно видел у ЛЕ Ra-75.

Измерение. Спектр полностью идентичен более поздним ЛЕЦ. Буквы Ц у ранних ламп нет, потому что эта цветность изначально задумывалась только с высокой цветопередачей. Однако потом её добавили, видимо ради унификации маркировок. Точно такие же пертурбации были с цветностью ЛХЕ, которая на самом деле должна была быть ЛХЕЦ, и с ЛХД, которая по факту ЛХДЦ.

The famous color 25 was actually invented by Narva in Germany during early 1960s. It was a halophosphate color with a higher CRI than usual. It was specially developed to be used indoor by people, so their eyes would not get tired after a long day of work. That is why it became very popular especially in factory settings where people needed a lot of good quality light. The light output oif the color 25 was lower than usual, but for the quality of the light, witch it was marginally better than regular halophosphate colors, it was a worth-while sacrifice. In Germany it was called universalweiss of universal white. It had the CRI of 70 and the later color code was 740. The color code 25 became its own uncategorized number so it would not be easily mixed up with other colors with in reality correspond to their respective color temperatures, such as F29 was warm white 29-530, F33 was cool white 33-640 and F74 was 74-765. But the F25-740 was its own number so that it could be easily identified without any confusion.

The tungsram factory in Hungary actually produced a huge variaty of colors under GE logo, but only four under Tungsram. When GE bought Tungsram in 1990s they started their own lamp line, but kept one old stmping line in witch they stamped Tungsram name, and those tubes with tungsram name only were exported to the countries that were trusting Tungsram products for their quality. So to keep the customers and avoid the confusion, GE left one line that still printed Tungsram on a small fraction of lamps that left the factory. That is why in Baltic countries and many other countries in EU it was comon to find Tungsram braded lamps and tubes, while in countries such as Great Britain they never exported tungsram tubes there and were only GE tubes that went there.

Under Tungsram they only produced four colors: F29-530, F33-640, F25-740 and F74-765. All other colors, uncluding regular triphosphor ones, only left the factory under GE brand. The colors that left the factory under GE were F25-740, F29-530, F33-640, F35-535, F36-960, F38-940, F54-750, F55-750, F60-765 and F74-780, 840, 830, 827, 860. This INCLUDED BOTH T8 AND T12 fluorescent tubes.

That is why in GB you could easily find T12 fluorescent tubes in their "Polylux" sleeves and in colors like 830. Yes, the Tungsram factory in Hungary that was bought by GE, up untill 2015 still produced T12 fluorescent tubes in triphosphor and halophosphate colors, and wattages included 15w, 18w, 20w, 30w, 36w, 38w, 40w, 58w 65w, 70w, 75w, 85w, 90w, 100w and 125w. We only saw in Europe 18, 20, 30, 36, 40, 58 and 65 watt fluorescent tubes. The sad thing was that in Europe itself you would hardly find any triphosphor fluorescent tubes in T12 flask, and in countries such as Lithuania they were nonexistant. The Tungsram factory closed its door for good after declairing bankruptcy in 2020.

I wouldn't be sure that it was Narva who introduced this colour, as colour HNW (Weiß) can be found in Osram catalogue of 1955, and in catalogue of 1958 it already has its number /25.

Its only advantage is slightly higher colour rendering (for the price of lowered efficacy), which has nothing to do with eyes comfort or fatigue. For some applications this could be profitable (e.g. for sales of coloured goods), for some not (e.g. regular offices). That is why these lamps were sold at the same price as 20(33)/640.

Numbering of fluorescent colours was not an easy matter, generally the native numbers did not correspond to colour temperatures at all, e.g. /10 – daylight (765), /20 – neutral white (640), /60 – red, etc. Only accepting the new international standard in late 90s helped to bring some order there. Though there still remain some 3-digit colours which do not obey this rule (e.g. /108, /150, /160, etc. by Philips).

Thank you Dominique for correcting me. I am still young and I try to learn as much lighting history as possible. I am aware that Osram had its own ridiculous color numbering system that didn't at all correspond to the color of the lamp itself, but what I was elaborating on was the the Tungsram factory, and how they managed to develop their own system that actualy corresponded to the color being used. The number 25 was adopted from Germans as the Hungary also started making that color tubes as well.


Well, I also wouldn't say that GE/Tungsram's numbering system was very straightforward with colour temperatures:

/29 – 3000K (ok, this could be explained by rounding)
/32 – 3000K again (why not /30?)
/33 – 4200K (?)
/54 – 6500K (??)
/55 – 6200K (???)