[BillA]

some comments from someone who has bought a lot of test equipment, done a bunch of testing, and then upgraded the equipment to start the cycle again, several times - and it is ongoing

I would suggest that the goal be clearly identified, and the experiment designed accordingly
the methodology used must yield data that answer the experimental goal
and the equipment used must have the capability of producing accurate and repeatable results

I state the obvious as it is apparent that some are not familiar with the 'design of experiments'
if one wishes to quantify a system's performance, then that is what is tested
if however one wishes to quantify the capability of a component, then the individual unit should be tested in isolation from the effects of limitations imposed by other parts of the system
-> this is the purpose of bench testing
(a simplistic analogy would be running an engine on a dyno vs. running the car on the track)

given that it is desired to quantify the capability of a component, what are the appropriate tests ?
since wbs are the topic of the day, and several are reported to be starting test programs, lets consider how such a program could be setup

the first step is to identify those use factors impacting wb performance
then to approximate the range of those conditions
then to identify the equipment necessary to create that range of conditions
then to identify the instrumentation necessary to quantify the actual conditions at that moment of testing
and finally to develop a written procedure (or checklist) so that all variables will be addressed in the same way each and every time
-> obviously detailed records must be kept both for data analysis, and more importantly, to be able to re-create a specific setup when some data 'won't fit' - to be able to retest

now this is a chore for component testing, it is a HUGE chore for systems testing

returning to wbs, what are the salient variables ?
specimen preparation (bp flatness and finish - how to quantify ?)
connection bore dia (stock, modified)
coolant flow (accuracy required)
pressure drop vs. flow rate
coolant temp (accuracy required)
heat source area
applied power (How Quantified ?, this is extremely crucial)
goop application (how thick ? - how do you know ? - did you measure ? -> big problem here)
clamping force (must be quantified, with numbers)
influence of ambient temp and air movement
die temp (the biggest problem of all)

quite a list
and any 'tester' who does not address each of these variables (one way or another) is ignorant, or a bull shitter
(feel free to quote me)

moving right along here
what equipment, with what degree of accuracy, is necessary to quantify these variables
different testers will have different 'standards', and budgets
but each of those variables listed needs to be quantified

pHaestus has commented on accuracy, and has discussed an article illustrating error propagation in calculations
I hope he does write this (soon !) as there are too many without the technical background to appreciate what constitutes a 'good' number
accuracy and resolution are not the same, and without some method of calibration its all make believe

do look at a tester's equipment list, and see what is said about calibration

all thermodynamic testing is 'touchy', and with the very small components WCers use the measurement increment is small as well
low resolution uncalibrated equipment can totally mask, or misrepresent, what we might think are 'significant' differences between units

almost forgot to mention that enough trials should be run to establish confidence in the results

testing is not so easy
BillA

EDIT: added pressure drop to wb variables