A metrologist wants to know that any variations in measurements are the result of variations of the parts being measured, not variations in the measuring devices or their users. Subjective interpretation of inspection or measurement devices is a complex variable that can influence the quality of the results drawn from that interpretation. Therefore, automatic inspection-and-measurement devices that take users out of the process must be more accurate. Well, maybe.

Interpretation of the device or the data
In this issue of Measurement Matters I am talking about variability in the interpretation of what the measuring device is communicating to the user. This is at the data collection part of the process. Another obvious source of error is from misinterpretation during the analysis of the collected measurement data, but that’s further into the process. Data recorded for future analysis are subject to sources of error due to user misinterpretation of what the measurement device is indicating. In other words, the measuring device may be working with great precision, but the measurement itself may be misinterpreted and lead to errors later.

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