I have never before seen a spec of 100uV for a Relay contact under 2A. If you are using CMOS voltages of 0V ( which is less than 100uV), this would be suitable because switching the voltage would easily exceed this criteria.
Although I have investigated many hundreds of relays and dozens of companies for a production environment there is usually a minimum current often 10% of rated current to ensure de-oxidation or "burning surface oxides". I suspect the insulative properties of these contact alloy surfaces has exposed a threshold to normal environmental stress. They don't always tell you how thin the flash gold plating is and what's underneath, whether it is 1u" flash gold plated or 30u".
If a smooth clean conductor in air requires 3kV/mm to bridge the gap then a 100uV minimum voltage would be equiv. to 100uV/3kV/mm = a 33nm gap. which is much smaller than a bug's whisker and other bug parts have been found to cause failures in some telecom relay contacts, especially attracted to some of the lubricants used.
There are many critical factors that make a Relay reliable; (besides V and I rating)
Contact style: Rivet ( high A), Needle ( high pressure), Crossbar (wiping action), Bifurcated Crossbar (best)
Contact plating: all contacts under 2A must be gold(Au) plated to reduce oxidation Contacts > 2A demand special materials for hardness, durability, high temp, high conductance to withstand the arc temperatures of > 5000'K such as Silver with Paladium, Platinum, Tungsten, Cadmium, Nickel, Copper,
Sealed From dust, or moisture or toxic atmospheres.
In truth there are hundreds of detailed electro-mechanical parameters to consider for form, fit and function of a relay which includes quality, load de-rating for inductive , DC or AC
There are just too many specs to teach you how to select a reliable relay and many differences in moving coil with greater sensitivity, wiping action, self diode clamping, automotive, PCB, bipolar latching, momentary, timers etc.
In case you are not familiar with current profiles from startup, these affect contact de-rating factors in the fine print.
- I suggest you start here learning here.
- With more categories here