This is a method used by Standex Electronics to test its contact resistance on reed relays, reed switches and reed sensors. Essentially we operate the reed contacts at about 100 times per second and look for the a measurement of the contact resistance about 1 millisecond after the contacts close. If the contacts are clean (no contaminants on the contacts) and the reed switch is tact, we usually get a good reading. But if there is the slightest problem, the contact resistance will not have settled down within one millisecond, and we reject it.
