Is Magnetic Scale Resolution the Same as Accuracy?

Magnetic scales are common measuring instruments used in many fields. When measuring with a magnetic scale, we often mention its resolution. But can resolution be simply equated with accuracy? This article explores that question and explains resolution, accuracy, and other evaluation metrics.

Difference between resolution and accuracy:
In magnetic scale measurement, resolution and accuracy are different concepts. Resolution describes the instrument’s ability to distinguish two adjacent signals or objects and indicates the smallest resolvable displacement. Accuracy refers to how close the measurement result is to the true value and represents the correctness of the measurement.

Magnetic scale resolution:
Resolution is the minimal displacement the scale can measure, typically determined by the distance between adjacent magnetic stripes on the scale. For example, a scale with 1 µm resolution can detect 1 µm displacement; actual measurement error may be smaller. Higher resolution allows finer capture of displacement information for more precise results. .

Magnetic scale accuracy:
Accuracy relates to the deviation between measurement results and the true value and is affected by mechanical structure, optical/electronic component precision, and signal processing. Accuracy may be expressed as a percentage or an absolute displacement. For instance, a 0.1% accuracy on a 100 mm measurement could imply a 0.1 mm deviation.

Other performance metrics include nonlinearity (the deviation from ideal linear response), repeatability (consistency across repeated measurements), stability, interference resistance, and temperature drift. These metrics reflect performance under various operating conditions.

Conclusion:
Although resolution provides finer displacement detail, it does not fully represent accuracy. Resolution describes discriminating capability, while accuracy measures correctness. When selecting a magnetic scale, consider resolution, accuracy, and other performance metrics according to application needs to obtain reliable measurement results.