12 May
2010
12 May
'10
11:02 a.m.
Many times I've seen problems with bad sockets
that looked good on the
ohmmeter because I pressed the lead of the IC hard to ensure good contact.
With a scope=2C you can see visually that the contact is good enough and th=
at no
additional pressure is needed. I don't need a low ohms contact with the
scope lead. A less than optimal contact is usually good enough( especially =
with
a 10X probe ).
OK, got you. It's almost doing a 4-terminal mesuremtn where the current
is supplied by the device under test, and the 'scope is the votlage
detector. As you said, assuming a reasonable input impedance on the
'scope, a poor contact at the probe tip won't matter much.
-tony