How does a digital multimeter measure AC voltage? My guess would be that the AC voltage is rectified and filtered into a DC voltage which is then measured, giving the peak voltage of the AC signal. Am I correct?
A follow up question: I remember reading from somewhere that multimeters cannot very well give accurate AC voltage measurements if the signal is not a sinusoid but a square wave for example. Is this true? If so, why is this? If AC measurement works by rectification into DC as I assume, shouldn't they measure other types of waveforms just as well?