Erik said
The ONLY way to measure switch resistance is to pass a known current and measure the voltage drop.

On going through the above, can i come to a conclusion that i could use a current source with which i could deliver 10mA at its o/p by connecting a series resistor at its o/p. So that all the voltage drops at that series resistor and thus passing the 10mA current only to the reed contact under measurement!

Erik said
You can't specify a voltage, the voltage is the drop across the switch AT a current. If you apply a voltage and the voltage is too high (20 mV may very well be too high) the switch is DEAD (melted)
I got it in this way:
When high voltage is passed through the contact the voltage drop accross the contacts could be 20mV (which is too high) and would lead to melting of contacts!

is it what you described?

- i think this is the case that could happen when the switch rating is exceded.


Suresh.