Hi, just wondering if anyone knows what metal is used in the contact zone of a mercury slip ring? ChatGPT tells me silver,gold or platinum but as mercury amalgamates with these I'm not quite certain it is correct? Yes mercury toxic etc but im just curious as to what was used (is used as you can still buy these new)..

Thanks!

 

This company offers various models. They would be an authoritative source of information.

 

I have seen graphite used as a contact material, but that was quite a while ago. It also comes to mind that in the mercury tilt switches of thermostats the contact elements seem to have silvery colored particles bonded to them. So it might be some metal that also bonds with mercury.
So the slip-rings might use a mercury to mercury contact scheme. That could be very reliable.