(Jordan V., Gerardo M.)
Today we replaced the MKS gauge at FC-C-1, this is the first 6 way cross inside the filter cavity tube enclosure, we installed serial number 390F00490, twice, yes two times. It turns out that the flange has some scratches on the knife edge, and it was not going to seal regardless of the effort that we put into it. Once the gauge was removed the scratches transferred to the copper gasket. We replaced it with serial number 390F00495, this one seems to be doing good. New conflat was leak tested and no leak was detectable above 2.42e-10 torr*l/sec.
The old gauge serial number is 390F00406 with a date code of June 2021.