After contact with the friendly Beurer customer service I now know, however, more:
The good news is a replacement bulbs there.
You can (and should) as a consumer the relamping also perform even without invalidating the warranty.
With the built-lamps is a fluorescent tube that, so I was told, "very likely" is produced by Philips.
Number of the TL40: 1
The designation of the replacement tube is: MP 45 3U
The price of this replacement tube when Beurer Customer Service is currently 19.90 EUR + 4.10 EUR for shipping / handling, for a total of 24.00 EUR.
The average useful life of this tube should be about 8000 hours.
The tube has in the course of this period of use until it eventually fails again, no significant loss of brightness, I was told.
As with a conventional neon tube it is easy to not turn back or starts to flicker when it is consumed.
The question of course is whether it really creates under normal conditions, to achieve these approximately 8000 hours of operation at all.
At one hour per day usage the many many years would.
Relevant is there rather how many power-ups will take this tube at all.
I myself have the Beurer TL40 now used and found that they helped me appreciably despite my first somewhat skeptical attitude common in the winter months.
I do not think that I merely imagining me, because after regular "light baths", mostly then when I sat at the computer, I felt during the day better (less lethargic) and could then sleep at night even again lighter than before, where I go and again had to contend with falling asleep.
I am glad to have bought the lamp - and as others wrote - I should have actually buy much more.
A small gripe, there are in my view nevertheless:
The lamp heats up quite strong and the plastic casing is then a slightly unpleasant smell, but which, after cooling, also disappears.
Just when you sit very close in front of it (the closer the better =) affects the smell in my view, especially at the beginning when it is still new, slightly uncomfortable.
Devalue the lamp so I however do not consider justified.
Therefore 5 *.
