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I was using my meter today to measure AC (120V 60hz house wiring) and noticed I couldn’t zero the meter. If I short the probes in Voltage AC mode, I see about 0.0030V. When I press the zero button, that value is shown instead of “zero” on the button. However, the value is not subtracted from the displayed voltage. It continues to read 0.0030V. The same thing occurs when trying to zero to wall voltage at 120V.
The zero function works as expected in DC and resistance mode, so I’m not sure what’s up. Is it not possible to zero the AC?
Hi, this issue still persists in the newest app versions. Does anyone have some input on this?
I’m pretty sure there is no such thing as zeroing in ac-measurements. There is a button for that, but it just does not do anything.. Hopefully.
What would you except to happen when you zero your ac meter? Filter anything below your threshold out or get negative ac-voltages, if you find lower level of voltage than your zero-level?
There will always be some noise when measuring and your example of 3 milli-VAC seems to be a very low one.
I would expect it to zero to the existing voltage, to display offset. So, for instance, I could zero it to the voltage of an AC line, then be able to see the actual change in voltage from the baseline when the circuit is in use. I guess that’s not how it works.
AC voltages always fluctuate, no matter what you do.. It would be much more helpful to use graph-mode or logging for something like that, so you might be able to see what happens on the grid and separate your own stuff from what your neighbor might be doing. But..
I mostly graph/log currents with mooshimeter, as there should not be anything interesting to see on mains voltage :D .. For AC i basically always use current transformers, so it is also much safer and easier.
If i do find some multimeter that offers to zero at mains voltage, i will mash it with a hammer, as it would be really dangerous. At least here in europe with 230/400v.
