UV Lights for urine detection

My UV light took a tumble out of the van and is now on its last leg, so it is time to upgrade.  I haven't been tracking what the "go-to" light is these days, but I just ordered 2 examples from a place called Blacklight shop, which looked like a good value.  I chose both the MBL-28 and the UVR-13 to see which one performs better and will post the results down the road.

Anyone have any other suggestions?

http://www.blacklightshop.com/

I got two 51 led flashlights off amazon for 15.00each seem to work fine. They work great in the dark and can pick up spots in some light! Did not come with a holder like one ones you got,that would be a nice feature.

Everbody raves about cobbs uv light a bit pricey at 250.00

http://www.cobbcarpet.com/zen/index.php?main_page=product_info&products_id=1384



This one on Ebay is comparable to the one you're looking at 375 NM for about a third of the price at $16.99

http://www.ebay.com/itm/UltraFire-WF-501B-375NM-UV-Ultra-Violet-LED-Flashlight-Blacklight-18650-Charger-/170889879422?pt=US_Flashlights&hash=item27c9d49f7e

That is the big difference between units on the market are the nm ratings.  I am no expert and know that UV light runs between 365nm - 400nm, but at what point does it really matter?  When I worked in law enforcement, our forensic teams used a super expensive model that was 365nm.  The medical units are also 365nm, which is a more pure lightwave, but does that really matter for urine detection?  I think the hydroforce ax174 is rated at 395nm or close to it.

Sometimes I wonder if it would be better to buy a screw-in UV lighbulb and just replace the customers ceiling light with it.  Those bulbs are 365nm and run around $100.  Screw it in and start marking the spots...hands free even.

It just seems like those who make these lights are holding a secret.  It is the same way when you are shopping for a tactical light in that some rate them by lumens and some by candle-power, so nobody can compare apples to apples.  What I want to know is what should the nm wave be and at what power works the best?

Is that too much to ask as a consumer?

"Ideally the power is centered around 385 to 395 nm wavelength. You don't want to see the visible light. That is not the portion of the spectrum that causes the "glow.""
Scott W.


The main advantage of the higher power is relative to how dark you can get the room.
Low power may be adequate in a completely dark room, but more power will give better results in areas that cannot be easily or sufficiently darkened.

I hear the yellow viewing glasses can make a noticeable difference.

Thanks Goomer, but that is where I sturggle. Nobody seems to agree on what part of the light spectrum is best. Some sites tell us that it is in the 385-395nm, like you quoted, while other sites say that the proper range is 365-370nm. Prices vary greatly according to what wavelength they provide, yet there doesn't seem to be a clear choice. Why does a 365nm cost more if that isn't the ideal range?

My goal is to find something that I can stand in the doorway of a standard room, with the overhead lights off and only curtain-veiled light present, and be able to survey for urine spots without having to walk around searching. Obviously, that will take some power, but the point of the proper wavelength is that it increases the glow strength, so that is the most important variable....but, nobody seems to agree on what the wavelength really should be.

milspec6 wrote:....but, nobody seems to agree on what the wavelength really should be.

I think it's because there is no ideal single wavelength, but a "best" wavelength range, because the "ideal" wavelength will vary somewhat from animal to animal due factors such as diet, medications, breed, health etc, as opposed to being a constant across every single animals, So the "ideal" wavelength to reach maximum florescence will vary somewhat from animal to animal, yet remain in that particular "range" that most light manufacturers seems to somewhat agree on.

At least I think that's how it works.....


"Different stains can fluoresce at different UV wavelengths.

No single wavelength UV light is optimum for every type of stain.

The wavelength on our LED lights works well on "normal" urine stains.

Pet medications and diet can shift the optimum wavelength both up or down for best detection."

Larry cobb

I've wasted too much time researching this topic and have accepted the reality that this is not an exact science. There is ample evidence to indicate that 385nm-395nm works fine at detecting urine spots. There is also ample evidence to indicate that the least amount of visible light would allow for greater fluoresence, so the 365nm also makes sense to me, even though it is a less powerful light.

The forensic boys used uv filters to adjust the ranges according to what they were trying to detect as there is no optimum wavelength for all stains, just like Larry states. That being said, the wavelength that they choose for urine, seman, sweat, etc. has a peak of 365nm, so I still lean towards that as the better choice.

I guess I will test out the two candidates that I ordered to see if either meets my needs. If not, I guess I move on and try Larry's.

I guess I'm not alone in this........the more I read/research The more confusing it is.

Deep rabbit hole.....I should have some reviews this weekend on the two lights that I ordered.

just buck up and spend the money for cobbs....

i am as cheap as they come, and tried cheaper ones....by far the best....AND I dont do a ton of urine...but its nice to knowits going to work when i need it...

ALSO....something to think about...

is how your eyes pick up the UV...Compared it at the experience (still hate that name) anyway some people could see the stains with out the lights...me I need the glasses, as my eyes pick up more of the light, so i need the filter...

get larrys light and be done with it....

ohh maybe ill check this place out that had yellow glasses for damn cheap...they work great to

I have no objection to buying whichever one gets the job done, price isn't the problem. In fact, those $400 plus floodlights look like the power champ, but I would be scared of scorching the carpet by being careless and in a hurry.

It may end up being Cobb's light, I just wish that it was easier to compare apples to apples when shopping for a UV light. I don't have any place local that I can compare products, so it becomes a guessing game based on reviews and ratings as to which one is right for me. That is what I don't like about the whole thing.

As a side note, wearing those amber lenses also helps your reading comprehension and aiming on the range. It has been an old trick used by educators to improve test scores and most professional shooters wouldn't compete without them.

I have both lights pictured above. I bought the Cobb light for $289.00. Later, on the advice of a friend from another board, I bought the e-bay light for $9.95.

Unless my eyes deceive me, I don't see any difference in performance between the two lights. There is, however, a difference in price.

I bought my 395NM light from Amazon. Free shipping on a 35+ dollar order and my light was about 15 bucks.

I think the Cobb's light is VERY overpriced for what it is.

My light works just fine with the amber glasses and shades drawn. I don't need total darkness.

http://www.amazon.com/gp/product/B001Q70A0G/ref=oh_details_o00_s00_i01?ie=UTF8&psc=1

Yes, THIS light works well. It's not a spotlight like you want. Neither is Cobb's.

the problem is, those multi bulb lights...you loose focus on the spots....

or rather you have to almost be on top of them...

granted i always pull the shades if possible, just makes it easier...

but i can scan a room from the door way, or rather quickly with cobbs...

those other ones....not as focused of beam....

The lights arrived and there will be a video posted this weekend. I was surprised at what I discovered...I think this will prove helpful to many.

(Just a little tease)

Which ones did you buy?

UVR-13 and MBL-28 from the Blacklight Shop.

The lights themselves aren't real flamethrowers, but the key is the wavelength of 365nm compared to the common 380nm-395nm that is being sold in this industry. There is a real difference and I think everyone will find it interesting....especially at the price point.

COOL I look forward to seeing it.

I'm anxiously awaiting your review, Robspec.  

Well, the video is a bust, without any real visible light being emitted, all you get is me talking to a ghost that only I could see:evil:   So, I am going to provide the details here for now until I can think of something else.

The premise was that to determine if a UV light operating at 365nm would be superior to the ones using 395nm of UV light.  The thinking was that since all 395nm wavelengths include some violet light which tends to muddy the image, that a clearer image would be possible through the use of a true UV light at the 365nm range as it doesn't emit any violet light.

In the photograph below, you will see the light beams of each light against a wall.  The one on the left is the 51 LED light emitting at 395nm while the one to the right is the 21 LED emitting at 365nm.  You can clearly see the violet hue on the left and that is the light which reduces the image quality.  There is no violet light being emitted by the one on the right, just a clean UV emission.



So, the test moved on to the urine stain.  This was in an actual customer's home and the large deposit was found next to a floor lamp.  I again used each light to see which one did the better job of detecting the urine deposits as there were no signs of the urine to the naked eye.

The LED light using the 395nm wave, flooded the deposit with a violet hue which made it difficult to see the entire deposit.  It was visible to me, but the purple of the light tended to wash out the detail.  We have all seen this ourselves, so it was no surprise.





Next up was the light operating at 365nm on the same deposit.  You will note that their is no purple-violet light in the picture, there was just a clear image of a large urine deposit in a greenish-grey color (it is much brighter in person, but the camera makes it look really dull).



So, it appeared that the 365nm light was the winner, right?  There was one extra variable to include and that was a pair of amber goggles worn to protect your eyes and improve contrast.  With the amber glasses on, most of that purple-violet light was filtered out.  In fact, the two lights provided similar images except that the more powerful 51 LED light was now brighter!

Conclusions:  If you wear the amber glasses, the flaw of the purple light is removed on the 395nm units providing a nearly equal playing field to the lights using 365nm wavelengths.  Being equal in image quality, the winner goes to the light with the greater power which means more photons are reaching the urine deposits and thus more visible light is returned to your eyes...urine deposit glow brighter.

I hope this helped somebody out there...I wish I had this information before I bought the 2 shorter wavelength lights, but sometimes you just have to test things for yourself.  The 365nm lights were still a good tool, just not the improvement that I was hoping to find.

Good info, Robert.

Theses two lights you're comparing are the two you bought this week from the UV light shop, or something else?

Did you find anything that's works in conditions other than total darkness?

The 2 lights were one that I had been using for years and the other was from that UV light shop.

Both of the lights did a good job in normal lighting, but I turned off the lights for the sake of the camera. The camera shows it a lot dimmer than it really was on the spot.

Since it is a matter of the shortwave photons creating an electromagnetic reaction in the urine deposit and thus returning a longwave visual light in return, it comes down to having enough energy into the deposit to off-set the light in the room. Maybe there is a way to increase the reaction in a more effecient way??

In both cases, the lights were at their very best at about 6-8 feet away. Any distance farther and the image loses its focus. I think that you really need the power of a plug-in style of light to really be effective in bright interior lighting.

Thanks for taking the time to compare and giving us feedback.

Too often someone is pimping something to sell to us, and whatever testing method they use, it tends to be in ideal condition in a lab someplace.

Real world results, in real conditions, are more valuable than anything else.

I don't understand what the deal is with the two you just ordered from the UV light shop?

Are either of them any good at all?.....if so, which one is best?