Kontrollwert

Kontrollwert is a German term meaning control value. It denotes a reference numeric value used to verify the proper operation of a measurement system, instrument or process. In quality management and laboratory practice, a Kontrollwert is typically a known control material or reference material with an assigned value that is measured regularly to monitor performance.

Purpose and use

Kontrollwerte serve to assess both accuracy (trueness) and precision of measurements. They help detect systematic bias, drift or random error and support traceability to standards. In laboratories, control materials with predefined Kontrollwerte are analyzed at specified intervals, and the resulting results are tracked on control charts. If a Kontrollwert falls outside predefined tolerance limits, corrective actions such as recalibration, maintenance or method verification are initiated.

Relation to other terms

Sollwert (target or setpoint) refers to the intended value of a process, whereas Kontrollwert is the actual measured result from a control sample used to judge the measurement system. Kontrollen are part of broader quality assurance practices, including internal quality control (IQC), external quality assessment (EQA), calibration, and method validation.

Applications

Kontrollwerte are widely used in clinical chemistry, environmental analytics, metrology, and manufacturing quality control. They underpin instrument performance checks, method verification, and routine quality assurance, contributing to reliable and traceable results.

Limitations

A Kontrollwert reflects the performance of a measurement system under defined conditions and is not a direct measure of patient samples or process outcomes. It relies on proper selection of control materials, appropriate tolerance ranges, and valid interpretation within a quality management framework.

See also

Sollwert, Qualitätssicherung, Kalibrieren, Kontrollkarte, Westgard-Regeln.