Perhaps the volume is expressed for calculations of heating
efficiency.

The volume of the cooking chamber, including the waveguide, is where
the RF energy of the magnetron will be converted, either by
interference with food or with atmospheric water molecules.

A larger volume would result in lower efficiency, as more of the power
is discarded by the forced air flow through or around the outside of
the chamber.

Still, if the volume advertised is greater than the chamber and the
waveguide, I can't see the point, and it would appear to be more of a
sales technique.

--=20
James Cameron
http://quozl.netrek.org/
--=20
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