Looking for recommendations for UV LED flashlight near 365nm

HKJ

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Huh, that is really interesting. I wouldn't expect a 365nm light to generate that much visible light. The one demo picture that Sunlite has on their website for the Slim UV gave me the impression that it was generating quite a bit of visible light, but given the overall awful quality of that image file I didn't take it for granted that the apparent amount of visible light was an accurate representation. It's also my understanding that a digital camera may make some UV light appear to be visible light. Based on your photos, the Sunlite does seem to do the best job of fluorescing the text, but I'm surprised at the amount of visible light.

I was also surprised with the amount of visible light and that is was white, but that said, it is not a huge amount of light, probably below 1 lumen.

My camera is a Nikon D300 and it has good UV and IR filter, but many camera's does not have good filters.

Do not expect the Sunlite to be the best light for everything, some stuff has better response with one of the other UV light.
 

parnass

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RyanA

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According to this thread, Peak offers to build UV flashlights at wavelengths of 350 and 360 nm using "laboratory quality UV LEDs from the Fox Group" upon request.

Best to call Peak on the telephone. They are good folks and very helpful.

:party:Woot. great info!:twothumbs
 

Ryanrpm

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This comment from Sunlite may clarify the 'visible light' that you guys say you were seeing from the Sunlite 365nm UV.

We can make stronger UV LED. Stronger UV LED will be bigger because it will require bigger heat sink.

The traditional epoxy housing 5mm T-13/4 is not designed for high power use. The epoxy will be gradually yellowing after exposure of UV light. We don't make 5mm LEDs, we make power LEDs. We make UV LED with glass lens to prevent degradation after use. .

There is no white light from this 365nm UV LED. This 365nm UV LED has a very narrow spectrum with the half width of about 12nm. It is power UV LED, the UV light is very strong, that's why you can see a lot of visible light. the visible light appear whiter than if you use 395nm UV because of its shorter wavelength. Both of our 395nm and 365nm LEDs are
power UV LED.

It's a little fun being the middle man. Get to learn a lot in the process.:)
 

HKJ

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There is no white light from this 365nm UV LED

The light might not be designed to emit white light, but somehow it does emit some white light, it might only be 1% (A total random number) of the total light emission, but it is very visible (because the UV is not visible).

It would be a problem if the light only emitted UV light, you would not know if it was on or off.
 

winston

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The 365nm Nichia that LEDWholesalers uses can't be the same part as the 365nm Nichia in the Xenopus. I've seen them both, and they are different beasts.
The Streamlight Stylus isn't 400nm. It's 375nm, but there just isn't much light coming out - visible or otherwise.

I was all ready to point out that this is the same old "Which UV light should I get?" post, but it's actually the most comprehensive list of UV flashlights I've ever seen. :clap:
-Winston
 

Antares

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HKJ said:
I was also surprised with the amount of visible light and that is was white,
Right, I'd expect there to be a small amount of visible purple light.

HKJ said:
Do not expect the Sunlite to be the best light for everything, some stuff has better response with one of the other UV light.
Right, understood. In my experience, the shorter the wavelength, the more limited the supply of products and the longer the wavelength the more plentiful the options. Right now I'd like to get a light in the 360-365nm range, but it's easy and cheap to get lights with longer wavelength for tasks that they perform better at. I came across this appliction matrix a day or two ago that purports to show which wavelengths are suitable or ideal for particular tasks.

I guess you have a good camera -- I just have a point and shoot digital and I found out recently that the sensor is able to detect UV and IR. For example, I learned that you can see the IR from a remote control by viewing it with the digital camera.


@parnass, Oh, ok, thanks for the link. I wasn't aware of that at all, I will look into it.


@Ryanrpm, Thanks for all of the info you've gathered. After you pointed me to their forum I posted in the thread you started, but for some reason they have not approved my post. Part of my post was asking what they mean by "power UV LED" -- I don't know if that's a brand name, a type of technology, a descriptive term, or what.

Do they know the details (like epoxy housing) they're mentioning about the Streamlight LED for a fact or are they just guessing? I don't know what LED is used in the Streamlight, but doesn't Nichia, for example, make a 5mm 365nm LED with glass lens?

I don't understand their explanation of the visible light. If the emission is confined to a narrow band peaking at 365nm, then even at high intensity shouldn't there be little visible light? And shouldn't the visible light that is emitted be purple?

This 365nm UV LED has a very narrow spectrum with the half width of about 12nm.
Does this mean that there is emission at +/- 12nm from 365nm -- so 353nm and 377nm -- and that the intensity of that emission is 1/2 the intensity of the emission that is at 365nm? (I'm not suggesting that there wouldn't be any emission farther than 12nm from 365nm, just wondering if this means it's a curve peaking at 365nm and at +/- 12nm the intensity has fallen to 1/2.)


HKJ said:
It would be a problem if the light only emitted UV light, you would not know if it was on or off.
I agree that if you're dealing with a UV light with very little visible output, it's ideal for there to be a really obvious way to tell that it's on. I guess there are a number of ways to do that, including perhaps having a small visible light LED indicator somewhere on the product.


winston said:
The 365nm Nichia that LEDWholesalers uses can't be the same part as the 365nm Nichia in the Xenopus
That's interesting. Can you describe the differences at all?

LED Wholesalers says they're using the Nichia NSHU590B LED.

Xenopus says their light has a beam angle of 10 degrees approximately, which would make me think they're using the NSHU590B, but they also say the output power is ~16mW, which seems more consistent with the Nichia NSHU550B (100 degree).

According to this page, the NSHU550B has a typical optical power of 2mW while the NSHU590B is 1.4mW. So 2mW x 8 LEDs = 16mW? Or perhaps the optical power of multiple LEDs is greater than the sum of the optical power of each individual LED and 1.4mW x 8 LEDs = 16mW?

Is it possible that Xenopus is using the 100 degree LED and the reflector in their light is directing that into a beam angle of 10 degrees approx.? It doesn't look like a very deep reflector, but it does appear that each LED is slightly recessed within a little scoop that would limit the spread of light away from the center of the head.

As seen here the NSHU590B and NSHU550B have a different physical appearance:
http://store.nichia.com/index.asp?Category=15&PageAction=VIEWCATS


Re: the Streamlight, based on things I've seen on the web, I think perhaps it used to be 375nm and they changed it to 365nm. The post on the Sunlite forum seemed to be suggesting that due to the way the Streamlight Stylus UV is engineered, the output would actually be at a considerably longer wavelength than the advertised one. You can see the actual quote in post #8.

winston said:
I was all ready to point out that this is the same old "Which UV light should I get?" post, but it's actually the most comprehensive list of UV flashlights I've ever seen.
I hear you. I considered not starting the thread because of that, but the reason I did is that I had found all of these models and I was hoping people could give feedback on some of them to help narrow it down.

Considering how haphazard it is to find out what products are available, and considering that I actually did end up finding all of them (the ones that I found), I'm considering creating a little finder application on my website to consolidate all of this information about what UV flashlight products exist and where to find them in one place. Would anyone care about that?
 

Ryanrpm

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@Ryanrpm, Thanks for all of the info you've gathered. After you pointed me to their forum I posted in the thread you started, but for some reason they have not approved my post. Part of my post was asking what they mean by "power UV LED" -- I don't know if that's a brand name, a type of technology, a descriptive term, or what.

Do they know the details (like epoxy housing) they're mentioning about the Streamlight LED for a fact or are they just guessing? I don't know what LED is used in the Streamlight, but doesn't Nichia, for example, make a 5mm 365nm LED with glass lens?

I don't understand their explanation of the visible light. If the emission is confined to a narrow band peaking at 365nm, then even at high intensity shouldn't there be little visible light? And shouldn't the visible light that is emitted be purple?


Does this mean that there is emission at +/- 12nm from 365nm -- so 353nm and 377nm -- and that the intensity of that emission is 1/2 the intensity of the emission that is at 365nm? (I'm not suggesting that there wouldn't be any emission farther than 12nm from 365nm, just wondering if this means it's a curve peaking at 365nm and at +/- 12nm the intensity has fallen to 1/2.)


Your explanation of the 12nm seems reasonable. But I myself have no idea. I'm very much learning as I go here.

The term "Power UV LED" or "Power LED" may just be a brand name. Or more likely, it is a descriptive term to describe the intensity of their LED's. They are indeed High Power, Application Specific, LED's. The deeper you go in UV wavelength, the more power it takes to get the same intensity. At least that's what the guy at Peak Solutions told me. So that explains why the 365nm Sunlite is 2w and the 395 Sunlite is 1w.

As far as the visible light being emitted at high power, that may be possible, but I would take Sunlite's word for it. They know more about it than I do. BTW, your 1st two posts there are awaiting review before being posted for public viewing....that's why there has been a delay.

Considering how haphazard it is to find out what products are available, and considering that I actually did end up finding all of them (the ones that I found), I'm considering creating a little finder application on my website to consolidate all of this information about what UV flashlight products exist and where to find them in one place. Would anyone care about that?

I would care about it. :thumbsup:
 

HKJ

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The term "Power UV LED" or "Power LED" may just be a brand name.

It is a description of how the led is made. A power led has a surface that can be mounted on a heatsink, the 3mm and 5mm led does not have this possibility.

Here is a picture of a power led mounted on a star:
DSC_3437.jpg


And a 5mm led:
DSC_3438.jpg
 

Ryanrpm

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It is a description of how the led is made. A power led has a surface that can be mounted on a heatsink, the 3mm and 5mm led does not have this possibility.

Here is a picture of a power led mounted on a star:
DSC_3437.jpg



And a 5mm led:
DSC_3438.jpg


Thanks for the clarification. Makes total sense.
 

Antares

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Ryanrpm said:
BTW, your 1st two posts there are awaiting review before being posted for public viewing....that's why there has been a delay.
I noticed that, but what does it take to get a post reviewed over there? -- they still haven't approved it.

Ryanrpm said:
I would care about it.
Thanks, I guess that's one vote for it. I just don't want to bother if there's going to be no interest.


@HKJ, Thanks for the description of power LED. Even after seeing your explanation, I couldn't find good basic information about it by searching Google. Is there any relationship between power LED and surface mount device (SMD) style LEDs, or are those two totally different things?


@BlueBoom, Thanks for the link. I've seen a couple of lights like that. It just seems like a really inefficient way to do it compared to using LEDs that emit UV, but I guess the effectiveness and cost effectiveness are of more practical importance. Do you own that light, and if so, how well does it work? I'm curious if that's the same as this light. They're the same body, both 14-LED and 3-AAA. The one I linked to does not show a picture of the front of the light, specify the wavelength, or mention using a Wood's glass filter vs. UV emitting LEDs, so it's inconclusive.
 

HKJ

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@HKJ, Thanks for the description of power LED. Even after seeing your explanation, I couldn't find good basic information about it by searching Google. Is there any relationship between power LED and surface mount device (SMD) style LEDs, or are those two totally different things?

To be a power led is has to be smd (At least I have not seen any leaded leds that could qualify as power led), but not all smd are power led, they need to be of a certain power before they can qualify. I can not give you a specific limit, 0.1 watt leds does not qualify as power led, but 3 watt does.
 

JNewell

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The chart linked above interested me so I dug out my three UV-ish lights and experimented a little last night. Subject lights are a Mini-Mag with the Terra-Lux drop-in, the Lighthound 9 (?) LED UV light and a deep purple (not UV) Photon. I was surprised at how different the results were. For example, only the Lighthound light would really light up my MV operator's license. I had not focused on how specifically you need to consider just exactly what it is that you want to use the UV light with.
 

Ryanrpm

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I noticed that, but what does it take to get a post reviewed over there? -- they still haven't approved it.

I saw it yesterday. In fact, it is there now.

According to Sunlite, .5w and a size of 24milx24mil is the minimums of a 'power' led.
 

Antares

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@HKJ, Thanks for explaning the relationship between power LED and SMD.


@JNewell, Yes, that chart is interesting in showing that a variety of different wavelengths are useful and ideal for particular purposes, as your testing confirmed. I wonder if the other 2 lights would be any more effective if you were wearing amber glasses. It's my understanding that they improve the visibility of the fluorescence at least in some applications and that they can be used with blue lights to see some of the effects that would otherwise require a shorter wavelength UV light.


@Ryanrpm, Oh yeah, there it is. Thanks!
 

coors

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Really nice thread, here. So much information! I recently purchased a 51-LED 385nm w/ Woods filter flashlight. The Sunlite 365nm @ 60mw looks quite interesting to me too. Anyone try to use the Sunlite 365nm for curing Norland?..does it work well?
The Nichia NCSU033A is capable of 4x the output of the Sunlite 365nm, but I haven't found a source yet for stars etched for reflow soldering this emitter to. If I can find a source for these stars then I plan to get one of these, but will also have to have a custom copper heatsink built for my little light, as well.
Does anyone know of any lower than 365nm wavelength UV LED emitters, currently available?
 

Ryanrpm

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Just the Peak LED Solutions which go down to 350nm.

Need to call them up.

I believe Sunlite will also create a custom wavelength...need to call them up too.
 
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