Can I know which is better and which is the true UV light? Thank you.
Hi Ghost, I recently did some research on UV lights because I wanted to buy one. I have looked at the 2 “UV” torches you linked from fasttech and I didn’t buy them because they seemed to be emitting purple light which is visible.
Now, it all depends on what your purpose of getting a UV light is but ultraviolet light is actually not normally visible to human beings. If you wanted “true UV” you should be looking for wavelengths of 380Nm and below. I settled on a 3W emitter that produces light with a wavelength of 365Nm from ebay. It hasn’t arrived yet so I cannot tell you any more about it. I’m sure the other forumers here have more info. I seem to recall “2100” having a PT30 UV light from Tank007.
You may have seen the thread over here .
so the 365nm will be the best. i try to find it, thank you.
365nm may not be the best for you. It depends on what you need with it.
Different materials fluoresce at different wavelengths of UV light, depending on the material’s absorption properties. So if you need to “see” something, you need to find out which wavelength it reacts to. If you need the UV for disinfecting purposes, 365nm will not be short enough. Note that handling UV light around 300nm and below is considered dangerous and requires protective equipment like safety glasses, UV sensor/detector, etc.
What did you need UV for?
—-Alfred.
If you just want to make things glow, yes it will work. But if you’re using it for something like inspecting money or ID cards or for UV inspection like dye penetrant you need a 365 nm led. Unfortunately most 365 nm led flashlights just use a few weak 5mm leds.
The only readily available high powered 365 nm UV led is the one from LedEngin and they aren’t cheap, a single die led on a star is $32. I have a custom made flashlight that uses one. They do emit dim white visible light so if you want pure UV you need to put a wood’s glass filter in front. But I really do like mine, you can make the plastic security strips in money glow, each denomination has a strip that glows different colors and driver’s licenses often have neat UV sensitive invisible patterns like California’s new licenses have a copy of your photo in UV ink that even glows the same colors as the original photo, old license had a California flag that glowed in the actual colors of the flag.