How is the accuracy of a precision measuring instrument defined?

The accuracy of a precision measuring instrument is defined as the difference between the average measurement and the true value. Accuracy refers to how close a measured value is to the actual, true value of the quantity being measured. When an instrument provides measurements that are consistently close to the true value, it is considered accurate. This definition is crucial in ensuring that measurements taken for maintenance and reliability assessments yield valid results that reflect the actual conditions or parameters being measured.

In contrast, the maximum error possible speaks to the limits within which measurements can vary but does not provide a clear indication of closeness to the true value. Consistency of measurements over time relates more to the reliability or repeatability of measurements rather than their accuracy. The range of measurement, while important for understanding the capabilities of the instrument, does not inherently inform about its accuracy in relation to the true value.