| Definition: | an adjective that, when applied to a quantity X pertaining to electromagnetic radiation, indicates :
— either that X is a function of the wavelength λ, symbol : X (λ),
— or that the quantity referred to is the spectral concentration of X, symbol : X
in the latter case, in French, "spectrique" is preferred to "spectral"
Xλ is also a function of λ and in order to stress this may be written Xλ(λ) without any change of meaning
NOTE – The quantity X can also be expressed as a function of frequency v, wave number σ, etc.; the corresponding symbols are X(v), X(σ), etc. and Xv, Xσ, etc.
|