Night Vision Anvis Tubes Developing Blems??

[Cjwise5]

These pics aren't great, but you can see faint, transparent dots that have formed in just the past 6 months. The only blemish in these Anvis 9 goggles when I got them was a single black spec on the center right of the first pic. It's clearly larger and darker. What is the expert opinion as to why this is happening? What can I do about it? I've been told something about "black boxing" the goggles??? basically leaving them turned on in a completely dark box or space for 8-10 hours . Thanks.

 

[Killswitch Engage]

looks like artifacts to me. a tiny spec of fiber, dirt, hair can get on the tube from normal use.

 

[Cjwise5]

Thanks for responding, but I'm a photographer/videographer by trade. I checked the glass to see if it was just dirty. That's the first thing I thought of. These spots are internal.

 

[Shifty6BR]

I think he is speaking internally...sometimes artifacts ie dust specks etc can be left inside and such and when disturbed move about and land on the inside/surface of the tube.

I have had this happen and opened up the diopter end and cleaned up...you will have likely have to re-purge if you go this route...I never did and had not a problem. Never owned Anvis tho just 14's ...ymmv

 

[Cjwise5]

OHH, that makes more sense. Thanks for clarifying that. Guess I may have to send the tubes in for service. Don't want to, but maybe I'll have to in order to remove the spots.

 

[Killswitch Engage]

yes...inside artifacts. as dumb as this may sound....jostling them around some as in helmet ride on the back seat of your truck on a rough road etc is usually what brings this stuff out and sometimes makes it go away. judging by what i see if they were mine id keep on keepin on with them.

 

[Cjwise5]

Ok sounds good.
there’s not much else I can do at this point. Can’t afford to get them cleaned or the tubes replaced.

 

[Flip#1]

I take my stuff apart and clean them periodically and I use can air for purging.
never have a problem getting moister inside. I am in NC. I have access to my nvg shop purging them but never had issues with the can air method.