EDIT - I am happy with the comments to the first question, so I will replace it with a different question that I would like answers to. The 2 scopes in question are the Tektronix TBS1072B and the Rigol DS1054Z.
The Tektronic has a CAT II 300Vrms input voltage safety rating.
The Rigol has a CAT I 300Vrms input voltage safety rating.
I need to do some 240Vrms mains measurements and would like to know the difference between the safety rating categories mentioned above.
I'm assumming the tektronic is the much safer scope to use for mains probing due to the higher CAT safety rating?
But can the Rigol still be safely used for isolated mains measurements (DUT through an isolating transformer with ratio 1:1 or 10:1)?
Or should I be considering differential probes as well?
Thanks for the replies.