Cleaning Rod lenses in optics equipment

[xusmee]

Hi,
We have an optical equipment that has a narrow entrance slit, on the other end of the narrow entrance slit two rod lenses are exposed. They are getting dirty for various reasons. Does anybody know of any handheld air/vacuum cleaning with thin nozzle that can penetrate the slit and even remove dust particles accumlated on the lenses?

Much appreciated...

 

[MATLABdude]

Welcome to PhysicsForums!

Have you tried optical-grade wipes, along with an appropriate liquid? Lint-free t-shirt material may or may not work, but if it's expensive, and/or hard to replace, you should probably go with the optical-grade wipes. It absolutely has to be wet, otherwise, it may scratch.

CAVEAT: my only experience in this field is from undergrad physics labs, and in cleaning of my glass masks. Also, don't clean front-surface with isopropanol / acetone! Depending on how it was made (and they're usually sputtered / evaporated / CVD'd metal on glass), you might end up rubbing it off!

 

[Redbelly98]

I would try this first:
http://www.thorlabs.com/thorProduct.cfm?partNumber=CA3

 

[xusmee]

I already tried the air can technique but it seems that the nozzle is thicker in diameter and I can't insert it into the slit and thereby spray on the rod lenses.It seems i am just dispersing the dust around the area..Same is the problem with making physical contact w/ the lenses. It's hard to make physical contact without opening up the module. Would you know if a thinner nozzle is available w/ the dust can.

 

[Integral]

The slits should be removable. If possible remove the slits, then dampen the center of a optical grade lens tissue with few drops of high grade methyl alcohol. Drag the moist spot across the lens. Ideally the dry end of the tissue will adsorb the alcohol as you drag leaving the lens dry behind. Repeat until the lens is clean.

If you can't get to the lens it will be nearly impossible clean.

 

[Redbelly98]

Yes, trying to get to the lenses through the slit is pointless.

It sounds like the lenses are in some kind of sealed-off enclosure. If that enclosure could be pressurized slightly, then dirt and dust would not get in there in the first place.

I'm also wondering, if the slit is the only way to get to the lenses, just how is all that dirt getting in there?

 

[xusmee]

The module that contains the lens is part of a bigger module so there are various other sources of dust getting in there. Think of it like a machine and the module that contains the lens is small part of the machine. I can take the machine apart and clean the lenses with physical application but this is not so useful in the field or in hospitals wherever a field service tech has to do it. So i was thinking of some way in which we do not have to open the whole thing (getting it back together involves lot of production time+labor).