I am using 34401A for 4-wire resistance measurement at the point of contact between gold-plated copper contacts. These contacts are just physically touching under a normal force which varies between 1 to 100g. I am using the default sampling rate of 34401A, 51/2 resolution and using LabVIEW to record data. I get values between 18-22mOhms but there are some points recorded as '0.0'. A value of 0 resistance is unexpected. I checked the wirings to see if that could be loose to cause it but to my findings wiring issue would only lead to a high resistance value, not low.
So, I want to know under what conditions 34401A can give 0.0 resistance reading. Could it be an issue of resolution that a measurement below least possible reading can result into this? What could be other reasons?