And presumably all that is covered on courses being run these days at ... wherever biomeds get their training these days?
Meanwhile, as background,
here is one of the many articles by John Backes to be found on the web. Others may be found
here.
Now, after re-reading the first article I linked to, I can in part answer some of my own questions. So, here goes:-
The
Differential Method copes with secondary earthing scenarios such as those that may be encountered with isolated mains power supplies in operating theatres (on pendulums, booms
etc. - the clue being that a LIM will be around somewhere nearby). Presumably because it doesn't "need" an earth to take its measurements.
The
Alternative Method can be used to determine current leakage
prior to activating the equipment (why would you want to do that?), or when testing in an IT environment
etc..
Good, practical stuff, then. Although I'm still not clear about the "IT environment" bit, I must admit (no proper earth available, perhaps?).
