Length of heater wire in the rods
A few weeks ago I did some analysis using data from the MFMP thermal dogbone test based upon the adapted emissivities which I found to limit the errors between thermal and applied powers.
I assumed two different length of heater wire in the rods, 4 cm and 6 cm.
These leads to two different heating distributions and thus also to two different power densities under the ribs.
Based on the found power densities I recalculated from the MFMP data the temperatures of zones 5 through 9 if the emsissivities would have been those of alumina.
For 4 cm of heating wire in the rods I calculated a temperature of 510.69 degree C.
For 6 cm of heating wire in the rods the temperature found was 440.78 degree C.
Since the temperature of 440.78 for the 6 cm heater wire in the rods is the closest to the reported 449.9 degree C in the Lugano report, it is an indication (as far as my assumptions about the MFMP test hold) that indeed the length of the heating wire in the rods is probably more then the 4 cm assumed.
Note also that the if we assume inflated temperatures due to using broadband emissivities on the Optris, that the average temperaure for zones 5 through 9 in Lugano would have been 376.7 degree C.
This value is largely outside the temperature range of 441 through 511 found by recalculating the MFMP data for different heater wire lengths in the rods.