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Old 18-03-2015, 09:17 AM
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pmrid (Peter)
Ageing badly.

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Join Date: May 2008
Location: Cloudy, light-polluted Bribie Is.
Posts: 3,742
Quote:
Originally Posted by glend View Post
That's impressive Peter. I might try the cooler box before I install a cold finger. Do you have any desicant or dew prevention measures inside the box? Condensation mangement is a major issue with the cold finger and likely requires a low pass filter heater.
Hi Glen.

No I don't. 2 reasons.

1. I have a small hole in each of the lower back corners to drain off any condensation that might pool inside the box;

2. With the operating camera sensor running at 10C above chamber temperature, I figure I am unlikely to experience "on-the-chip" condensation if I maintain a temp range of 5-10 inside the box. Hope I'm right about this.

I base this on the formula:

Td = T - ((100 - RH)/5.)

where Td is dew point temperature (in degrees Celsius), T is observed temperature (in degrees Celsius), and RH is relative humidity (in percent). Apparently this relationship is fairly accurate for relative humidity values above 50%

On that basis, the dew point last night when relative humidity was 55-60% i.e.:

Td = 16-((100-60)/5)

Peter
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