a measure of the ability of anything to transmit radiation, equal to the ratio of the transmitted flux to the incident flux; the reciprocal of the opacity. For a plate of material the ratio of the flux leaving the entry surface to that reaching the exit surface is the internal transmittance
Symbol: τ. Compare reflectance, absorptance
transmittance in American English
(trænsˈmɪtəns; trænzˈmɪtəns)
noun
1.
the act or process of transmitting
2.
the ratio of the radiant energy transmitted by a body to the total radiant energy received by the body