Les you might be interested in this.
Some early numbers from my evolving test setup.
Quite preliminary at this point but I thought I'd share this with you chaps.
A copper die, 140mm^2, nominally 12x12mm but is a little smaller in reality.
A matching fluxblock with 3 thermistors. Again nominally 12x12x13mm but a little smaller due to lapping and so on. I do have exact measurements.
The "sphere" waterblock.
Calibration of the primary fluxblock channels is good, the middle sensor has a rough cal, the Die sensor is calibrated. Water Ts are roughly calibrated, they are high resolution so their curves are linear, I don't expect much error with these.
~0.039 C/W for a 140mm^2 die. No correction done for heat shadow effects etc.
A logfile
here for those interested.
Many things going on that need to change, a power supply for the DAQ independent from the heater for a start.
I am seeing a few rather curious things happening. Fun to have the resolution to see them finally.
What is good to see is that heat flux through the fluxblock is linear. The deviation is minute. I will not use three sensors in the next 100mm^2 fluxblock, I do not think it is necessary based on the data from this one.