Related Experiment Video
Updated: Jul 13, 2025
10:22
Split Point Analysis and Uncertainty Quantification of Thermal-Optical Organic/Elemental Carbon Measurements
Published on: September 7, 2019
8.3K
Measurement uncertainty
Neda Milinković1, Snežana Jovičić1
1University of Belgrade-Faculty of Pharmacy, Department of Medical Biochemistry, Belgrade, Serbia.
Advances in Clinical Chemistry
|October 18, 2023
Summary
Measurement uncertainty in laboratory medicine requires understanding metrology concepts. Continuous evaluation of all laboratory phases, especially extra-analytical ones, is crucial for accurate results.
Area of Science:
- Laboratory Medicine
- Metrology
- Measurement Science
Background:
- The metrological concept of uncertainty in measurement is increasingly integrated into laboratory sciences.
- Understanding metrology terminology, traceability, and commutability is essential for proper implementation.
- Measurement uncertainty in laboratory medicine considers the entire laboratory process, not just the analytical phase.
Purpose of the Study:
- To highlight the importance of continuous evaluation of all laboratory phases for measurement uncertainty.
- To emphasize the critical role of extra-analytical phases in measurement uncertainty.
- To discuss the challenges and the need for balancing the understanding, evaluation, and application of measurement uncertainty data.
Main Methods:
- Continuous monitoring of all phases of the laboratory process.
- Utilizing internal and external quality control data for uncertainty calculation.
- Applying metrological concepts of traceability and commutability.
Main Results:
- Measurement uncertainty is fundamentally linked to the entire laboratory process, with extra-analytical phases significantly impacting results.
- Internal and external quality control data are key for quantifying measurement uncertainty.
- Increased awareness among laboratory experts regarding measurement uncertainty has been observed.
Conclusions:
- Effective implementation of measurement uncertainty requires a holistic approach, encompassing both analytical and extra-analytical phases.
- Ongoing monitoring and evaluation are necessary to manage and reduce measurement uncertainty.
- Achieving a balance in understanding, evaluating, and applying measurement uncertainty data is vital for practical use.
Related Concept Videos
03:37Uncertainty in Measurement: Accuracy and Precision
73.8K
Scientists typically make repeated measurements of a quantity to ensure the quality of their findings and to evaluate both the precision and the accuracy of their results. Measurements are said to be precise if they yield very similar results when repeated in the same manner. A measurement is considered accurate if it yields a result that is very close to the true or the accepted value. Precise values agree with each other; accurate values agree with a true value.
73.8K
00:59Uncertainty: Overview
570
In analytical chemistry, we often perform repetitive measurements to detect and minimize inaccuracies caused by both determinate and indeterminate errors. Despite the cares we take, the presence of random errors means that repeated measurements almost never have exactly the same magnitude. The collective difference between these measurements - observed values - and the estimated or expected value is called uncertainty. Uncertainty is conventionally written after the estimated or expected value.
570
02:46Uncertainty in Measurement: Reading Instruments
38.3K
Counting is the type of measurement that is free from uncertainty, provided the number of objects being counted does not change during the process. Such measurements result in exact numbers. By counting the eggs in a carton, for instance, one can determine exactly how many eggs are there in the carton. Similarly, the numbers of defined quantities are also exact. For example, 1 foot is exactly 12 inches, 1 inch is exactly 2.54 centimeters, and 1 gram is exactly 0.001 kilograms. Quantities...
38.3K
01:20Random and Systematic Errors
11.0K
Scientists always try their best to record measurements with the utmost accuracy and precision. However, sometimes errors do occur. These errors can be random or systematic. Random errors are observed due to the inconsistency or fluctuation in the measurement process, or variations in the quantity itself that is being measured. Such errors fluctuate from being greater than or less than the true value in repeated measurements. Consider a scientist measuring the length of an earthworm using a...
11.0K
01:10Propagation of Uncertainty from Systematic Error
534
The atomic mass of an element varies due to the relative ratio of its isotopes. A sample's relative proportion of oxygen isotopes influences its average atomic mass. For instance, if we were to measure the atomic mass of oxygen from a sample, the mass would be a weighted average of the isotopic masses of oxygen in that sample. Since a single sample is not likely to perfectly reflect the true atomic mass of oxygen for all the molecules of oxygen on Earth, the mass we obtain from this...
534
00:59Propagation of Uncertainty from Random Error
704
An experiment often consists of more than a single step. In this case, measurements at each step give rise to uncertainty. Because the measurements occur in successive steps, the uncertainty in one step necessarily contributes to that in the subsequent step. As we perform statistical analysis on these types of experiments, we must learn to account for the propagation of uncertainty from one step to the next. The propagation of uncertainty depends on the type of arithmetic operation performed on...
704