> If the objective is to compare the temperatures, then one has to ensure > that the > input _power_ to both coils is identical. It is not enough to just > _measure_ the > input power. It needs to be _actively controlled_ to ensure that it is > identical. >
I beg to disagree. If we have a large COP (> 2), in spite of eventual variations in the input power of the reactors, the difference of temperature will be huge (hundreds of degrees) and the only explanation will be excess heat. > Since P=I^2*R, if the resistance changes, then the current needs to change > too, > in order to maintain constant power. If the coils are in series, and they > have > different resistances, then they must have different powers, since the > current > through both is identical. I completely agree. But I do not believe we are going to see large differences between resistances, except in cases of heater failure. But even if we see large variations of resistance between reactors, we can measure it and take it into account in the input power. If we have significant excess heat, it will be easily visible in the difference of temperature. But, again, I do not expect large changes in heater resistance. Ergo, they can't be placed in series. > They also can't be placed in parallel, since identical voltage over both > would > ensure a larger current through the coil with lowest resistance. > The problem with this approach is that it is impossible to measure the current on both reactors directly (not inductively) with the same instrument without interrupting the current. This interruption, or the use of two different ammeters, will give the skeptics exactly what they need to question the results. > In short each coil needs to be powered and controlled independently, and > power > consumption of each measured and logged to prove that the power > consumption in > both remains the same. > It will be hard to convince the skeptics that there were no hidden sources of power or errors of measurement in this case... I believe the assumption that the resistance of the coils will not change is not a so hard assumption. The wires used for heater coils are designed to withstand large temperatures and other harsh conditions without significant variation of resistance. Regards, Alberto. > > Regards, > > Robin van Spaandonk > > http://rvanspaa.freehostia.com/project.html > >
