Are Refractors Nitrogen Purged?

[Wookie (Ryan)]

I noticed the inside of my refractor's front element was a bit smeary and wanted to clean it.

Upon unscrewing the front optical cell I could smell a pungent odour.

I am now wondering if I need to have the telescope re-purged if it was purged with nitrogen or similar.

Could anyone give advice on this matter?

Thanks.

Ryan

[Hans Tucker (Hans)]

I would think no. Unlike Binoculars, some which are Nitrogen purged/charged, one end of astronomical refractors is open to enable change of eyepieces for varying magnification. Maybe the fixed magnification spotting scopes might be purged/charged with Nitrogen.

What brand and size of scope do you have?

[Wookie (Ryan)]

Awesome, thank you very much Hans for the reply.
The optical cell is from a Chinese manufacturer and is threaded so there is no play when returning it back to its original position (collimation issues).
I have a set of binoculars that fog up in one eye when cold/rainy hence my question (they need re-purging).

Thanks

[dannat (Daniel)]

no only spotting scopes & WP binoculars -most refractors are open at the ep end -except for the petzval types with rear elemnents

[Wookie (Ryan)]

Thanks Daniel - very much appreciated.

I wonder what that smell was - glue?

[blink138 (Pat)]

hmmmm................ the pungent odour sounds a bit funny!
nitrogen is odourless is it not?
pat

[brian nordstrom (As avatar)]

That smell is from the matt black paint they use on the inside , some are worse than others , and yes it smells pungent for sure .
Brian.

[LewisM]

Yep, matt black paint. It remains odourous indefinitely. My 30 year old Tak still is smelly at the dewshield :LOL:

[Wookie (Ryan)]

Thank you very much for your replies. That's definitely piece of mind.