That makes sense and I've never had to replace any of the o-rings. I was
just curious.

On 3/11/2019 11:15 AM, wrote:
On Monday, March 11, 2019 at 4:56:13 PM UTC, Dan Marotta wrote:
Not being a mechanical engineer, could anyone enlighten me as to why the
o-rings are installed internally in the socket rather than externally on
the probe?Â* In either case the o-rings are getting rubbed each
installation/removal cycle and it seems light lubrication, like the skin
oil from one's nose, would work nicely. That's how I lube the probe on
my Stemme.

And, BTW, the o-rings would be oh so much easier to replace...

In ESA probes the UN sockets (eg for triple probes) have the O-rings in the socket and the ST sockets (eg for TE/Static double probes) have the O-rings on the aluminium probe fitting but those ones are more prone to fractures of the fitting on older probes - at the O-ring groove of course.

--
Dan, 5J