Internal Surface Roughness Can Turn a Probe into a Contamination Reservoir

What the evidence preview establishes

The new probes had rougher internal surfaces than older probes, and process residues were retained within their mechanical imperfections. This supported a connection between inadequate internal finish, cross-contamination, and signal instability.

Why this case matters

Specify and verify internal as well as external finish on fluid-handling probes. Pair surface imaging with residue chemistry, cleaning validation, and functional carryover testing rather than relying on alloy designation alone.