Equation 3 · Part 7 · How Scientific Instruments and Metrology Actually Work
subscript
subscript
What this part means
The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.
Its job in the formula
A subscript distinguishes a version, component, step, or member of a quantity. It does not automatically mean multiplication.
Full expression→subscript→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 subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.
Open the illustrated subscripts: which member of a family? guide →
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.