What if my scope's inputs are marked 300V RMS? (For example DS1054z)
What if I use one, or a pair, of 10x attenuating probes?
What if I use one, or a pair, of 100x attenuating probes?
If the oscilloscope can measure up to 300 Vrms, 220 Vrms the measure can be
However, you must comply with all safety precautions of manual. Usually it is an isolated power supply oscilloscope, for example, an isolation transformer or battery power, the right mode choice and divider probes.
Measurement 220Vrms mains via OWON XDS3102 oscilloscope with battery (see from 15:25, only russian language, sorry):