أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
Yes in some cases it can be useful.
YES TO ELIMINATE SIGNAL NOISE FREQUENCY.
The most common practice is using earth line that is connected in one end to the instrument (Clean) earth and the other end should be left open to let the noise move to the earth and not let it make noise loop in the earth line.