Measuring Relay contact resistance.

[fuzzzy]

relay contact resistance

Hi,

I'd like to measure relay's contact resistance using a NI Data acquisition device interfaced by usb to my PC and LabView.

Do you think are 12bit AD conversion enough to do it?

what is the best way to measure a so little resistance in your experience??

 

[flatulent]

measuring relay contact resistance

You need to use a special set of probes called Kelvin Contacts. You are going to have problems with the instrumentation because the relay contact resistance is probably lower than any other part of your measuring circuit.

The special probes have one set of wires where you put a constant current. Then the other set of wires is used to measure the voltage. You may have to solder the wires to the relay.

 

[fuzzzy]

contact resistance relay

I thought i could measure it using some circuital configuration like wheatstone bridge or something similar. could it work?

I need a fast sistem not particularly precise.

 

[DrWhoF]

measure relay

12-bit is not enough.
For 4.095V at 12-bit you have 1mV resolution and this will be not near resolution which you may need to measure such low resistance. I think you should look at at least 16-bit A/D.
DrWhoF