I was doing a little research about the maximum voltage rating and found very little info on one particular aspect.
I was interested in the maximum voltage between Input Lo and Sense Lo, but only the manuals of the keysight dmms provide this info (200Vpk), and only for the truevolt series. For the 3458A i couldn't find nothing, same for the keithley dmms.
Do you have any info regarding this limit?
I was also wondering if a voltage present between the Sense lo and Input lo terminals could throw off the measurement on the input side, but i doubt this may be the case.
Edit: for example the manual for rigol dmms regarding 4 wire resistance measurement states:
LO Sense/200 mA-LO protection limits: 0.5 Vpk. The current input fuse
on the rear panel provides the current passing through LO Sense/200
mA up to 500 mA protection.
But it seems a very weird explaination, because if the protection would kick in at only 0.5V this would severly limit the capabilities of the DC ratio function.
Edit 2: so, apparently the rigol shares the sense lo terminal with the 200mA current input and doesn't have DC ratio function, so a limit this low makes sense now.
From siglent manual:
HI Sense-LO Sense protection limitation: 200Vpk.
LO Sense-LO protection limitation: 200Vpk.
It seems the siglent also has 200Vpk between LO input and LO sense, tho in the second line they forgot to write "LO input"and wrote just "LO"