>If you work on hardware long enough you run into all kinds of things that make you realize just how little you know. I was part of a team commissioning all of

>If you work on hardware long enough you run into all kinds of things that make you realize just how little you know. I was part of a team commissioning all of the process analyzers in a new chemical plant. We had an oxygen analyzer (measures oxygen content in a process stream) that kept giving off problematic readings. Every single flange and tubing fitting upstream of the analyzer, as well as the analyzer itself, was leak checked repeatedly to no avail. One of the chemical engineers recommended we start leak checking downstream. Problem solved. Ambient oxygen was getting into the system downstream, diffusing upstream against the process flow, and was being detected by the analyzer. All the non-chem e's were mindblown.