I found relay replacement instructions for the PXI-2532 in NI Switch Help and it listes the Meder CRR05-1A. I'm unable to find a data sheet for the CRR05-BV50543 on the Meder website, might I ask the source of that part number and if you know if there's a data sheet available?
I'm a little confused...
PXI-2532 Specification, physical characeristics section, indicates relay contact material is Rhodium
Meder catalog desctiprion for the CRR05-1A indicates gold plated "leads"
I suspect the suffix on the part number you provided may include contact plating options etc. but can't confirm from the Meder website.
The CRR05-1A is an equivalent replacement for the 2532. The relay contact material is Rhodium on both; this refers to the plating on the internal contact and reed, which are sealed in a tube containing a noble gas and vacuum. We use Rhodium because it has no stable oxides and therefore doesn't build up oxidation from the spark that occurs each time we make a connection. Externally, we plate the relay contacts with gold because gold resists environmental oxidation and maintains a lower path resistance than oxidized copper.