Resistance measurement voltage - multimeters
That will vary by multimeter but most professional level ones will include that information in the datasheet and it can vary by range. Here's the table from the documentation for an Agilent 34461A:



Using that I just measured a cheap "no name" meter and it had a maximum 320 mV voltage across all ranges. So hopefully that gives you a rough idea, and you could find further information in the datasheets for the better brands of meters.