At 08:07 PM 6/6/2010, Richard Knoppow wrote: > Selenium cells can deteriorate with time even when >stored in favorable conditions. The enemies are heat and >moisture. The cell edges are sealed to prevent entry of >moisture but the seals often break down with time.That is true for cheaply made selenium cells, such as those used on most US lightmeters, Weston being the exception. The cells made by Weston, Gossen, and Metrawatt are simply impervious to leakage save for physical breakage or direct submersion. Those will last for many decades -- I have some Prewar Metrawatt meter which still works perfectly.
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