Glossary · Sensors and measurement
Measurement accuracy
Also known as: Accuracy of measurement
German: Messgenauigkeit
In metrology, measurement accuracy is the closeness of agreement between a measured quantity value and the true value of the measurand. It is a qualitative concept; quantitative statements use measurement error or measurement uncertainty.
- Sensors
- Standards
In one sentence
Measurement accuracy is how close a measured value comes to the true value, a qualitative concept expressed through error or uncertainty.
Example
To improve the measurement accuracy of a temperature loop, the team calibrates sensor and transmitter together and corrects the combined error.
How it applies
- Engineering: The measurement accuracy of a loop depends on the whole chain: sensor, wiring, transmitter, analog input and scaling, plus installation and process effects. Datasheet figures of single devices are only part of it.
- Calibration: Calibration against traceable references quantifies the error; Measurement traceability links the result to national standards.
- Quality: Measuring equipment used for product or safety decisions needs defined accuracy requirements and a check that the equipment meets them.
- Documentation: Avoid unqualified statements such as high accuracy. State the error limit or uncertainty and the conditions under which it applies.
Measurement accuracy vs. precision
Measurement accuracy relates to the true value. Precision relates to the spread of repeated measurements. Good precision does not guarantee good accuracy, because a systematic offset can remain.