Is this condensation/frost?

[symmetal]

No harm in trying an argon purge I imagine. Is that from the aerosol cans used in wine preserving? It's heavier than air so should stay around the sensor while the cover's replaced.

What's it like if you cool to 0C instead of -10C. The difference in dark current between 0 and -10 is fairly small.

Alan

[Anthonyexmouth]

2 hours ago, symmetal said:

No harm in trying an argon purge I imagine. Is that from the aerosol cans used in wine preserving? It's heavier than air so should stay around the sensor while the cover's replaced.

What's it like if you cool to 0C instead of -10C. The difference in dark current between 0 and -10 is fairly small.

Alan

I tig weld so got argon on hand. Could cobble a little purge box together I think. Bit don't want to waste argon if it's not any good. 

As for temp, -10 produces much cleaner images compared to 0 on the 294. 

[symmetal]

As your sensor chamber may not be airtight which is causing your problems, filling it with argon may likely be a temporary solution until it leaked out. Worth a try though if it doesn't cost too much. 🙂

Alan

[Anthonyexmouth]

Well, I bought a sensor cleaning kit and also done an argon purge of the chamber and it seems to have fixed it. Not sure what part of that helped but fingers crossed it's cured