I am in a frenzy of packing so I must be brief. I will be off line for a wee while now as well, due to a trans-Atlantic move.
Briefly. Les: Your ramblings pack a punch, I realise I need to start over, I'm very impressed at you being able to make sense of my meandering excellery. I find it almost impossible to follow my own stuff after a few days, let alone anyone elses.
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puzzling over L=0.008m now appearing (rather than the original 0.01m).
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This is the effective L for FB-Water, ie WB+TIM. I was checking the apparent power for all the sensors as sanity check and to try and get a better power average. You will notice that this value is only used for the T2-Water power calculation.
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As I understand you have set the 100% Efficiency as that at a Water Temp of 0c( W=Wo - 0.2635Tw)?
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Correct but at average water temp, not 0C. This is the elusive and as you say somewhat arbitary relationship between W and water temp. As I said above, the curve it is derived from is W vs water temp. This is very dependent on what measurements (at what water temp, voltage, frequency etc) have been taken so I concur, I am not happy either. In fact checking myself I would go as far as to say trash this, it can't be done this way. (Although I think the curves show pretty close to what the behaviour would be, but the offset is the unknown and unfortunately exactly what we're after)
The Efficiency vs W chart. There's another Excel sheet I've put up ("conductivity tester.xls" which a possible situation closer to what is likely to be reality. I agree, a constant CPU-MB dT is unlikely.
I'm missing data. Need MB temp but too many variables in that.
Some approaches show promise, but I think the uncertainties may be too much. Shame, I had some hopes for this approach.
The poly manipulations, a good trick, the Excel command INDEX(LINEST(y,x...x^2...x^3),1...and..2...and...3 ..) can give the constants for any order polynomial. Help is worthless. Check it on the sheet to figure it out. It gives the same numbers as a chart trendline equation but to far more significant figures.
pHaestus. Great data. I wish I had time to look at it immediately. Curious that W is so high.
Summary of the Flux block so far is that it gives a value for W to water, a value for TIM joint C/W, and a value for WB+2nd TIM joint C/W. All dependent on how much one trusts ones sensors.
Secondary paths need more work. Perhaps readings down to very cold water (Swedish winter here I come) would show a "knee" in the power readings which might be the point at which there are no secondary losses i.e. CPU temp<MB. the relationship of CPU temp to "electrical" power needs to be known, distinguishing from secondary loss is difficult.
Cheers guys
Incoherent