Phil Allison has brought this to us :
Ralph Mowery wrote:


That should be done with any piece of equipment. Practice with it and learn
the odd things about them.

** As Clint Eastwood might have said: " a man's gootta know the limitations
of his test gear ... "


Where I worked there were many wires in a conduit carring 120 volt control
voltage. With a digital meter there was so much induced voltage you could
not tell if a wire was really active or not. You had to put some kind of a
load on them. YOu could take an analog meter and start with a high voltage
range and then switch to a lower range. If the meter stayed in the same or
near the same physical position, it was just showing the induced voltage.
Even with a wire disconnected at each end,it would still shock the crap out
of you due to that voltage.


** Electricians once regularly used 40W bulbs in a protected, hand held
fittings to test if circuits were live - see pic.

https://img1.etsystatic.com/068/0/63...18127_nbxf.jpg

The AC plug was replaced with two probes in the examples I saw.

I guess it was important to test the bulb before each use ...


... Phil


Some used 2 bulbs in paper bakelite tubes wired in series then they
could test line to line or line to neutral with the same device without
worrying about the voltage or about spurious couplings of mythical
voltages like you can get with meters especially Digital meters.

Once in college Elec Eng Lab, a cotractor wanted to test 3 wires,
rubbed 2 together and closed down whole large building. when asked our
instructor agreed that was not the accepted method. :-?

--
John G Sydney.