One of the best examples of monitoring and measuring equipment is one we're all pretty familair with - the car dashboard and instrumentation. As has been already discussed, most car temp gauges aren't calibrated, but the speedometer should be - because you're likely to risk some kind of penalty (well, in most countries) for either ignoring it (!) or it being inaccurate (I have experience, I nearly got a ticket for that!).
Similarly, fuel gauges are notoriously non-linear (most of the cars/trucks I have owned a plagued with such a gauge) so estimating when to stop for fuel is difficult, given that fuel stations may not be close, as the gauge registers 'E'. We compensate by stopping more frequently to 'top up' rather than trust the gauge - which wouldn't make sense in a business environment.
So, given some journey objectives - to arrive on time, without a blemish on your driving records etc., some car instrumentation needs calibration for measurement purposes, some don't because they are indicators, used to monitor......