For a WR 340 heat transfer of height 
with a liquid slab of thickness 
, 
or 
is the physical constant which governs the microwave water heating process [4], [7] :
= 7.35 230 dB.° C/m = 1.690 dB.° C/mm = 0.194 °C/mm where is in mm.
![\[\frac{be}{\beta}= 222,5 mm^3/ ^oC \]](http://bouarfamahi.com/wp-content/ql-cache/quicklatex.com-fd4ce8619d78a18d7235f8bf3d95cfe5_l3.png "Rendered by QuickLaTeX.com")
Using experimental data 
and 
, the value of 
, 
and 
can be deduced through the data given in Figs.1 and 2 in conjunction with the above formulae. 
is a fraction of the total temperature variation .
Fig. 1 Approximate conjugate ratio along the length of the heat tranfer.
For = 0.990 = 4.6 
= 4.6v = 4.6 
For = 0.999 = 6.9 = 6.9v = 6.9
Fig. 2 ratio dependence on the relative error.
For = 0.990 = 
= 0.78 
For = 0.999 = = 0.85
is related to the process parameters with the formula :
°C = 3.79 (KW required)/GPM
