What maintenance of the probe is sensible or required?

In principle, the whole pressure system is maintenance-free, as long as the end pieces of the probes are always greased before insertion, and the measuring heads are wiped from time to time with a clean cloth. Never use compressed air or pointed objects for cleaning / testing! If the heads have been cleaned under running water, please ensure that all water is removed from the tubing before take off - NOT BY USE OF COMPRESSED AIR! The o-rings of the probes with the end pieces ST1 and ST2 should be regularly inspected for wear / tears (magnifying glass!) and replaced if necessary.