"Searcher7" wrote in message
news:fe1a23c1-9b49-49c9-856c-
On Dec 13, 5:36 pm, Tim Wescott wrote:
There are no "normal" environmental conditions -- only the
environmental
conditions that people of limited imagination assume is normal.

So that you will understand what I meant, the switches will not have
to operate in space, under the ocean's surface, immersed in harsh
chemicals or substances, or temperatures below or above what humans
consider comfortable.

Harsh chemicals include ammonia from cleaners and sulphur from eggs.
Silicones can cause some strange problems when they break down in
electric arcs too.