At 07:11 02/17/99 +0000, Nigel Goodwin wrote:
>One final point, what does having the scope earthed protect you against
>anyway?. Is there anything else apart from breakdown in it's internal
>mains transformer), or some kind of short between incoming live and the
>case.

well, the point is that often the scope's case is connected to its earth.
if you have to disconnect the scope's earth from the power earth (which is
approx. your potential), it is because you want to put the scope's earth on
a different potential -- which means, a different potential from =you=.
which would be right on the case, right? now i touch my scope every now and
then when working with it, don't know about others... so i definitely want
to be sure the scope's case it at approx. my potential. connect it to the
power earth is a good means to assure this (except when there is a short in
the scope, but that's another matter).

ge