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Why does UV light appear white vs bluish?
I'm curious why the the two UV lights appear to emit different colors and make things appear differently. One light has LEDs that emit violet colored light. The other is a glass tube that seems to emit white colored light.
Using a UV invisible ink pen, both UV lights will light up whatever is written or drawn. And if you just shined the violet colored light on yellow, it will appear brownish. With the white colored light, it will appear yellow. And with something coated with blue liquid laundry detergent, the violet colored light illuminates blue while the white colored light illuminates a faint white.
So I'm curious why these 2 UV lights would make things look so different when they're both supposed UVC with the same wavelength.
1 Answer
- Robert JLv 79 months ago
The UVC component may well be the same wavelength.
Anything you see in not "UV"...
The overall generating system is different. The glass tube will probably be a mercury vapour type lamp.
They naturally produce a lot of UV and the ones for normal lighting include filters to block that, as it can be dangerous at high intensities.
The LEDs most likely produce UV directly and any visible light is either stray output or from fluorescence of some part, possibly as an indicator they are on.
Be careful and use protective goggles - many types are powerful enough to cause eye damage or sunburn (and possibly skin cancer, long term) even though the visible part is not very bright.