Sensitivity

In an image intensifier, the photocathode sensitivity, measures the efficiency of the photocathode at converting incoming light into electrons.

There are two different measurements of photocathode sensitivity, luminous transmission sensitivity and radiant sensitivity.

Photocathodes have a spectral response, which means that their sensitivity differs depending on the spectrum of the light.

Luminous Transmission Sensitivity

Luminous transmission sensitivity is measured in microamperes per lumen ($\mathrm {\mu A} /\mathrm {lm}$).

Radiant Sensitivity

Photocathode radiant sensitivity is measured in milliamperes per watt ($\mathrm {mA} /\mathrm {W}$).