The following order helps you avoid wasting time:
- First, the resolution. An instrument that displays readings to the nearest 0.1 mm with a tolerance of 0.2 mm cannot validate anything. No study will be able to make up for that.
- Next, accuracy. All it requires is a calibrated part and an operator: it’s quick, and any significant deviation can be corrected through adjustment or calibration.
- Linearity if the range of applications is broad.
- Save the R&R for last. This is the most expensive process: multiple parts, multiple operators, multiple repetitions. It’s best to start with an instrument that’s already in tune.
Finally, two different instruments that are supposed to yield the same results may differ in several ways, and determining whether they are interchangeable requires a specific study. Comparing two methods assesses whether they can be substituted for one another: it does not indicate whether the methods are valid; it indicates whether they agree with one another.