I have no practical experience with sensors but for those gained from a few university courses. In one course, we were re-assembling systems on a weekly basis,

I have no practical experience with sensors but for those gained from a few university courses. In one course, we were re-assembling systems on a weekly basis, and the touch-screens we used would all return somewhat quirky offsets, so I had to calibrate the input after each re-assembly because I could never be sure which module I was working with. I learned to never really trust a sensor. And this was an undergraduate course. I would have assumed that in safety-critical applications, in a mature industry, performing every possible check on a sensor reading would be the obvious thing to do. Was this particular case just out of the ordinary, or is it really that uncommon to do that?