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conical-directional transmittance

[7.5.3.6] τ(ωt;θt,φt)

The ratio of transmitted flux, collected over an element of solid angle surrounding the direction, to the incident flux limited to a conical solid angle.

Figure 20
Figure 20

Note: The direction and extent of the cone must be specified, and the direction of collection and size of the solid angle “element” must be specified.

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