Onzekerheidsmeting

Onzekerheidsmeting, or uncertainty measurement, is a fundamental concept in metrology and scientific experimentation. It quantifies the doubt that exists in the measurement of a quantity. No measurement is perfectly exact; there will always be some degree of variability or deviation from the true value. Onzekerheidsmeting aims to express this deviation in a standardized and meaningful way.

The International Organization for Standardization (ISO) provides guidelines for expressing measurement uncertainty, most notably in the Guide to the Expression of Uncertainty in Measurement (GUM). This guide defines uncertainty as a parameter, associated with the result of a measurement, that characterizes the dispersion of the values that could reasonably be attributed to the quantity being measured.

There are generally two types of uncertainty contributions: Type A and Type B. Type A uncertainty is evaluated by statistical methods, typically by analyzing a series of repeated measurements. Type B uncertainty is evaluated by means other than statistical analysis of series of measurements, such as manufacturer's specifications, calibration certificates, or expert judgment.

The overall measurement uncertainty is usually expressed as a standard uncertainty, often denoted by 'u', which is a standard deviation. Sometimes, an expanded uncertainty, denoted by 'U', is provided. Expanded uncertainty is obtained by multiplying the standard uncertainty by a coverage factor (typically 2), providing a wider interval within which the true value is likely to lie with a specified level of confidence. Understanding and quantifying onzekerheidsmeting is crucial for interpreting experimental results, comparing measurements, and ensuring the reliability and validity of scientific and industrial data.