Clariman wrote:How do I make sure I'm properly earthed- stand on the floor with bare feet? Are bare feet on ceramic tiles earthed? Do I touch something metal when doing it?
I know
exactly what they mean.
Over the years I've used a variety of "voltage" detectors. They only work well if your body is fairly well Earthed. Your body is, electrically speaking, a noisy environment. Not sure which is worse, the electrical currents flowing through your body as part of your nervous system or the currents induced into you from impinging radio waves. Probably the latter. Whatever, there are degrees of Earthiness in things, including yourself.
If you hang on to a metal water or gas pipe (with a good electrical connection to our planet) or any metal (class 1) electrical equipment, or indeed anything that conducts and has a good connection to ground then the electrical noise measurable in your body (with respect to ground) will be less.
Many devices rely on your body's Earthiness as a reference for measurement.
So for example the "voltage" detector I currently use is unreliable if I don't hold it. If I prop it up so that the bit I'd normally hold is leaning on something Earthed then it works fine. If I'm up a glass-fibre stepladder it probably won't.
Chris
PS You can test this. If you get an oscilloscope and just touch the probe there will be a humongous signal on the display (usually 50Hz mains hum). If you then touch Earth this pretty much flatlines.)