UV dye question

Just curious, but we have a hydraulic based machine at work that is leaking pretty bad. Unfortuntely it is an older machine that isn't easy to get into with other oil based and coolant systems in the machine. I'm looking at running a uv reactant dye through the hydraulic system to trace the leak back to it's source. The dye is a 365nm uv reactant, so my question is this. How likely is it that it would glow using a 405/445 laser with a beam expander, or would it glow at all?

I figured if I could do that, it would be quicker since anything I order will take forever to get here right now.

Thanks for the help, and apologies if this is a stupid question.

More than likely. Do you have the name or an absorption/fluorescence spectra of the dye?

You might have a problem though, depending on how far the fluorescence is shifted. If the stokes shift is small you wont see the fluorescence through the goggles, as the goggles will block the fluorescence too.

If you must use a laser try a very low power one, maybe around 1 mW, or you wont see the fluorescence over the intensity of the dot. If you're lucky your dye might phosphorescence and in this case you'll see it after you turn off the beam.

Thinking about it, it would actually be better to buy a UV flashlight in the 360 - 380 nm
region as you will then only see the fluorescence....:beer:

The problem with the low power flashlights is getting close enough with the light. Due to the size of the machine, and obstructions I'll be shining it from 3-4ft away.

I know the mix ratio for the dye, but it only lists the 365nm for wavelength, no range.
I may just have to ordera uv light, and wait on it. Both my 405 and 445 are too high-powered to use like this then.

The problem is that they will over power any fluorescence you might otherwise see. With a flashlight at 360 - 380 nm you wont see the spot ie light created by the torch, as your eyes aren't sensitive to those wavelengths, and this is why you'll be able to see the fluorescence.

You could look into a thrower or flood to zoom style flashlight, with an aspheric, as these will easily cover the 3 - 4 ft, but to be honest most std flashlights will work over that distance! Id just buy a normal UV flashlight and try it, you can always move the LED to an aspheric based host if the beam is not collimated enough! :beer:

dye probably came with a cheap light. Find a lens and make that cheap flashlight throw better. You can use magnifying lens, but better might be an aspheric.

There are places where you can buy high powered 365nm LED lights, they are kind of pricy, though, as in several hundred dollars. There are also other UV lights which are much cheaper, but may or may not (usually "may not") be 365nm.

Just FYI was curious too. Looks like UV 365 nm aren't that pricey! I found a few on Alibaba, DX, Kaidomain, Manafont and Amazon. Cheapie: Professional UV Inspection Flashlight 380-385nm - 16 Ultraviolet LED - Amazon.com

Here's a review of a few: Review: UV light shootout, seven lights tested | BudgetLightForum.com

This company specializes in lights for oil and grease contamination detection: UV Detection of Oil and Grease :beer:

I've got UV reactive dye that works great with 405nm pointers if you need some

If it's "leaking pretty bad," doesn't that mean the source is obvious? What am I missing?

^^^this... Just wash the machine, and look for the leak

michael.

fyi not sure about your dye but, I have used a 300mw 405nm bluray laser with the lens removed, to replace a uv dye lamp for checking for leaks in an hvac system and I can tell you it worked like a charm in my case. Also I can add that the laser goggles adds to the visibility of the dye. It may be a bad idea and may not work with your dye or have the range you want but it is possible and I had good results. Also with the lens removed I cannot see it as to hazardous esp wearing the proper goggles.