Measurement Uncertainty is a parameter associated with a test result and is best described as the dispersion of values that could reasonably be attributed to the measurand (a measurand is a quantity, property, or condition which is measured).
As an ISO/IEC 17025 accredited laboratory Illinois Crop Improvement must evaluate and properly communicate the uncertainty of test results. Test procedures are grouped into one of four categories for purpose of developing an Uncertainty Budget for each test.
Many of the tests offered by Illinois Crop Improvement do not require Statements of Uncertainty. These include qualitative or semi-quantitative tests (Category 1) and recognized test methods that address major sources of uncertainty and how results are presented (Category 2).
Tests in Category 3 are physical, chemical, environmental, or biological/microbiological test methods that are based on published regulatory or consensus methods for which uncertainty is not defined in the method. This includes Crude Fiber, Oil by Petroleum Ether Extraction, Protein by Combustion (N x Conversion Factor) as well as Oil, Protein, Starch and Moisture and True Density by NIR. The Measurement Uncertainty varies by test and by the measurand. It is relatively easy to communicate that “True Density” is ±0.010%. Proximates such as oil, protein, starch and fiber vary by commodity and product.
Category 4 methods include non-standard methods that need identification of all components of uncertainty and detailed measurement uncertainty budgets. Ethanol fermentation services offered by Illinois Crop Improvement are based on research conducted and published by the University of Illinois. The method is the only service Illinois Crop offers in Category 4. Internal studies have shown that the Ethanol Fermentation Yield Measurement is ±0.030 gallon per bushel.
If you would like more information on the measurement uncertainty for Category 3 tests please contact us. (Posted 9/8/2022)