${\displaystyle s=\frac{Y}{X}}$

Note 1 to entry: If the detector signal is Y₀ in the absence of input, and is Y_t when there is an input X, the responsivity is ${\displaystyle s=\frac{Y_{\text{t}}-Y_{\text{0}}}{X}}$.

Note 2 to entry: The term "sensitivity" is no longer used.

Note 3 to entry: This entry was numbered 845-05-54 in IEC 60050-845:1987.