Re: Feeler: Osram PL TB450B 1.6W (Not M140)
Okay, I've done some wavelength testing. The wavelength at 300mA is 440nm. I can only
test at low power for several reasons.
- I don't want to burn my ruler/wall/grating.
- I don't have a neutral density filter.
- The only lens I have is B coated and reflects quite a bit of blue. COD is quite undesirable.
- I don't have any OC/partial mirrors to provide a limit that way.
My confidence in this measurement is quite high due to some other very accurate
measurements with a 532nm DPSS laser. It isn't off by any more than 5nm at the
absolute worst. It would be even better if I had a multiline HeNe, but no such joy.
Either this one just happens to have a low wavelength or I did overheat it when I put the
heatshrink on.
I was experimenting with several different "filters" due to the lack of anything real. The best
hope was a shade 10 filter designed for welding masks. That turned out to block all of the
blue light. It is most likely an absorptive type and not reflective like safety glasses. I kept
turning up the power because no light was going through and it started melting.
It wasn't
even an inch in front of the lens, nowhere near the focal point. Only a faint yellow light
actually goes through. It is quite similar to the safety glasses in that regard. Luckily it
was just an old scratched up junk filter that is pitted by welding slag.
I think I'm going to try making a hole in something round and putting it on a motor shaft
since I have plenty of CD/DVD/BluRay spindle motors just lying around. Does anyone
have a better idea? It's either that or stacking a bunch of lenses out of old sunglasses.
If there are no further objections, I'm going to go ahead and declare this GB officially open.