UV Doesn’t pick up human “stuff” (urine, saliva, etc.)

My UV doesn’t illuminate any human “stuff” (urine, saliva, etc.). Anyone know why?

CSI TV shows have been lying to you… As far as I’m aware that’s just how it is. Few things actually light up under UV.

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Probably want to check the wavelength of UV you’re using.

Not sure what wavelength you’d need, but 365nm doesn’t pick up any of the things OP mentioned.

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I haven’t tried it, but i had some UV of undiscolsed wavelength that I’ve used some years ago, they highlighted the hell out of animal pee (cat and dog) and everything they slobbered on. It also picked up everywhere that people missed the toilets, and generally worked better after the fluids had dried and the minerals had crystallized. On “fresh” fluid, not so much.

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380-385nm reflects light on urine. 365nm doesn’t.

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Not so, the ‘average’ UV wavelengths we use to pick up flouro markers and get GITD stuff glowing doesn’t show up urine.

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It’s a new Wurkkos HD01 Pro with a 365nm wavelength light advertised to highlight bodily fluids, scorpions (yeah, I have a big scorpion problem where I live! LOL), etc. But it just works like a blue light.

Scorpions glow a lot under 365nm.

“Blue light” sounds like it doesn’t have a filter?

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Most high power LED’s technically emit blue light. :stuck_out_tongue:

Are you supposed to wear special glasses when using a UV light? Is it harmful to your eyes (if you’re not staring straight into the light!)?

The AI said:

  1. Blood: 400-450 nm (blue UV light)
  2. Sweat: 320-400 nm (UV-A light)
  3. Semen: 400-450 nm (blue UV light)
  4. Urine: 350-400 nm (UV-A light)
  5. Skin flakes: 280-320 nm (UV-C or UV-A)
  6. Fingerprint residues (oils): 280-320 nm (UV-A light) or 500-600 nm (green-yellow)
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Quote:
The AI said:

  1. Blood: 400-450 nm (blue UV light)
  2. Sweat: 320-400 nm (UV-A light)
  3. Semen: 400-450 nm (blue UV light)
  4. Urine: 350-400 nm (UV-A light)
  5. Skin flakes: 280-320 nm (UV-C or UV-A)
  6. Fingerprint residues (oils): 280-320 nm (UV-A light) or 500-600 nm (green-yellow
    Un-quote——————————————————————————-

I’m going to go workout (#2), then urinate (#4), then scrape my arm with a knife (#5), then go ahead and cut myself with the knife (#1), point the light at anything in the house (#6), then, ohhhh boy, (#3)!

Treat it the same way as you treat any other high powered light - don’t aim at your or anyone else’s eyes, or directly at a mirror or other high reflective surfaces. Apart from that UV-A is pretty tame and there’s nothing to worry about.

Oh yeah. We don’t get them in the UK, apart from sone non-native imports, so we’re not used to them. I remember sitting out in the evening in southern France and had brought my Solarforce with UV drop-in on holiday with me. I was sat in a drystone walled courtyard with scrub bush all around the place and when I flicked that light on the whole place lit up with glowing scorpions in every crack and crevice around me.

Fairly well freaked me out :fearful:

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My Sofirn SF16 causes urine to fluoresce, though not spectacularly. The light uses ZWB2 filter and that’s probably why - without it the reflected violet-blue visible light may make it hard to tell what’s fluorescence and what’s reflected.

I wonder if I can find some ZWB2 and tape it over my UV light?:thinking:

Convoy sell the filters, though they’re rated at 365nm.

I don’t have a specific a 380nm light, but I definitely see better results with a more powerful 365nm torch than a little button cell keychain light.

Looking online for specifically 380-385nm lights will turn up a few dedicated pet urine detecting lights that claim that wavelength.

Thanks to all.

Kaidomain sells 380nm LEDs, if you can solder it might be interesting to grab a convoy or some other light with 6V driver and swap this LED in. B35AM/719 drivers from Convoy should work well with this.