Metrology is “the science of measurement, embracing both experimental and theoretical determinations at any level of uncertainty in any field of science and technology,” as defined by the International Bureau of Weights and Measures (BIPM).

Display metrology means using a scientific approach to measure (i.e., quantify) the visual output of a display. The primary output of today’s digital displays is light, which can be measured in terms of a display’s brightness, color, contrast, and other visual qualities.

Spectral power distribution vs. spectral sensitivity

There is more than one approach to quantifying and characterizing a light source, however. We can measure the absolute values of a light’s electromagnetic output, called its spectral power distribution (SPD). The SPD of a light source is typically displayed as a graph that represents the relative intensity of the source at each wavelength.

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