Equation 2 · Part 1 · How Scientific Instruments and Metrology Actually Work
Symbol N
What this part means
N is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Its job in the formula
N is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Full expression→Symbol N→Article meaning
The passage around this formula
The GUM’s central move is to treat every measured or estimated quantity a result depends on as a random variable with its own estimated standard uncertainty, and then to propagate those uncertainties through the mathematical relationship that produces the final result. If a measurement result y is a function of N input quantities, y = f(, , , ) , the combined standard uncertainty is obtained from a first-order Taylor expansion of that function:
Learn the underlying idea
A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.
Open the illustrated variables: a letter stands for a value guide →
See this notation across published equations →
Sources cited in the article section
- [2] Evaluation of measurement data — Guide to the expression of uncertainty in measurement (GUM), JCGM 100:2008 ↗
- [3] Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results ↗
These citations provide research context; check each source for the exact claim it supports.