[murphyv310]

Originally Posted by G8UWM-MildMartin

Does you Hameg do differential measurements?
Some could: A X10 probe in each channel, select "invert" for one channel and "add".
One probe tip to chassis, t'other used as normal. Both "earth" clips removed or safely taped up out of the way.

Hi.
Although that will work I still feel its not the safest approach.
Personally I'd be buying an isolation transformer before other test equipment.