We've recently purchased an STXL-6303 which I understand should cool to 60°C below ambient. However, I cannot get it to go below -35°C absolute, no matter what the ambient temperature. We are currently averaging around +10°C ambient so I would expect to be able to cool to about -50°C. Is the spec wrong? Do I have a faulty camera? Or am I just not configuring it right? The results are consistent between CCDOps and MaxIm DL 6. The ambient temperature at the time of the screen shot was +9.5°C so -50 should be achievable albeit at close to maximum power. Best regards, Tim Long
Never mind, I found this thread: http://www.diffractionlimited.com/forum/threads/stxl-cooler-limits.3747/ Which clearly states that there is a limit of -35°C absolute. Technically, this means that the spec is incorrect because the camera cannot in fact cool to 60 below ambient unless ambient is above 25C. That's a little disconcerting because there's no mention of that anywhere that I can find in the specifications or documentation. This sets false expectations and I would like to suggest that perhaps the spec on the web site should include this limitation. I do understand the reasons for the limitation and I can see that it is eminently sensible. Best regards, Tim Long
Thanks for the feedback. In reality delta-T isn't a single number and depends on a variety of factors. In general TEC coolers are more efficient at higher temperatures and can achieve bigger deltas when ambient is warmer. This is a good thing when you consider that warm weather is exactly when you need the extra delta.
