### Strutt Help

Conformal Area Source Propagation Loss
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**Strutt|Propagation|Conformal Area** provides the correction for a conformal area, given the length, width, height and distance in metres from the source.

The image below illustrates that a conformal area has rounded corners, which will result in the conformal area calculation becoming equivalent to a point source calculation for large distances.

This is implemented as:

`x = 10log_10(S)`, where

`S=(A+B)(2C+pi r)+2 pi r(C+r)+(AB)`

Note that this calculation assumes the source is located on a reflective surface; at large dimensions the results from this calculation converge to the same as hemispherical distance attenuation: Spherical Correction.

References:

Arup Electrical Services Guide (red book) - *source of the Conformal Area image above*

Comments or suggestions to
strutt@arup.com