Search results
Results from the WOW.Com Content Network
Relative uncertainty is the measurement uncertainty relative to the magnitude of a particular single choice for the value for the measured quantity, when this choice is nonzero. This particular single choice is usually called the measured value, which may be optimal in some well-defined sense (e.g., a mean, median, or mode). Thus, the relative ...
The measurement uncertainty budget must be re-determined for each measured value. Examples. 1. A measured temperature value is read every day. Decisive influencing variables are ambient temperature and air pressure, which can vary every day. 2. The measurement uncertainty strongly depends on the size of the measured value itself, e.g. amplitude ...
Systematic errors can be either constant, or related (e.g. proportional or a percentage) to the actual value of the measured quantity, or even to the value of a different quantity (the reading of a ruler can be affected by environmental temperature). When it is constant, it is simply due to incorrect zeroing of the instrument.
According to ISO 5725-1, accuracy consists of trueness (proximity of the mean of measurement results to the true value) and precision (repeatability or reproducibility of the measurement). While precision is a description of random errors (a measure of statistical variability ), accuracy has two different definitions:
The mean value calculated from the ... Standard errors provide simple measures of uncertainty in a value and are often used because: ... If values of the measured ...
The "biased mean" vertical line is found using the expression above for μ z, and it agrees well with the observed mean (i.e., calculated from the data; dashed vertical line), and the biased mean is above the "expected" value of 100. The dashed curve shown in this figure is a Normal PDF that will be addressed later.
measured value (uncertainty) In the last notation, parentheses are the concise notation for the ± notation. For example, applying 10 1 ⁄ 2 meters in a scientific or engineering application, it could be written 10.5 m or 10.50 m , by convention meaning accurate to within one tenth of a meter, or one hundredth.
In physical experiments uncertainty analysis, or experimental uncertainty assessment, deals with assessing the uncertainty in a measurement.An experiment designed to determine an effect, demonstrate a law, or estimate the numerical value of a physical variable will be affected by errors due to instrumentation, methodology, presence of confounding effects and so on.