Estimation of Measurement Uncertainty

Laboratory customers expect accurate and reliable results. Any measurement by any laboratory is estimation of correct result. Testa and calibration labs need to ensure lesser uncertainty in measurement by controlling factors affecting measurement. This course will help students to understand importance of measurement uncertainty, identify factors responsible for uncertainty and step by step approach to calculate uncertainty. Customers expect lab results to be accurate and reliable. Results are considered accurate and reliable when those are repeatable / reproducible in different working conditions at different times. estimated uncertainty indicates probable variation in the results. Lesser the variation, better is accuracy and reliability. This course discusses about various factors which can affect measurement results and ways to control same. Test laboratories are supposed to declare uncertainty in case of borderline results whereas calibration laboratories are supposed to declare uncertainty for each calibration result. Higher the uncertainty higher is risk to customer i.e. accepted product/ result may be non-acceptable. Hence it is always a good practice to ask laboratory about systematic result of uncertainty estimation. Uncertainty is always expressed along with confidence intervals. at 95% confidence interval lab is sure that in 95% of cases of repetitive measurements results will not vary beyond declared expanded uncertainty. Expansion factor depends on confidence interval.