Mid-Calibration Data

Now that we have several calibration cycles done at different conditions, we are starting to analyze the data we have gathered and we are seeing some interesting things.

First, the baseline performance of the cell for the different calibration runs.  

We are seeing a pretty good agreement from run to run.  We are expecting to operate in the 250C range.  At that range, one watt shows approx a 2 degree C rise.  That means if we achieve 5 watts of excess energy we would expect the temperature to be 10 degrees C higher than this baseline.  These aren't final numbers, but it gives us a rough idea of what to expect.

Cal1, Cal2, Cal3 are all Helium 

4 a, b, c, d are all at the conditions we expect to be loading the wire at in a few days:  75%H / 25%Ar at 3.5 bar starting pressure

5 is the same gas mix starting at 2 bar.

When we take the runs from set 4 we get a much tighter agreement (sorry, no graph at the moment).  Malachi has done an error bar estimation from 3 identical runs and found the average +/- 3% within the 95% confidence limit.  Though preliminary and needing more study, it appears we are looking for a minimum of 3 watts excess energy before we could say we have excess energy.  5 watts or more would be easier to identify with certainty, and 15 to 20 watts like Celani demonstrated would be clear as glass.  (And thanks to Nicolas we know exactly how clear that is.)  

The other more intriguing thing we have seen is the impedance of the Isotan 44 wire (the type Celani uses as his precursor) behaving strangely.  See the graph below.

Cal 1 is the first test run in Helium.  Notice the impedance dropping extremely quickly. 

Cal 2 and the rest behave in almost the same way to each other with decreasing impedance as the temperature goes up with a dip that bottoms out at 250C.  This is roughly the temperature that Celani's cell operated at.

Cal 4b is different, though.  This run is the only one in which we heated with the nichrome wire instead of the Isotan.  Though there was still a tiny voltage and current through the Isotan wire, the resistance showed a pretty consistent positive slope with temperature.  That might suggest that the strange resistance curve happens only when a certain amount of current is passing through the wire.  Or maybe only when a certain current runs through it and a certain amount of hydrogen might have absorbed into it.  Suggestions?

It is possible that there was enough residual hydrogen in the cell even after achieving a vacuum in the range of 10^-5 torr before Cal1 that the Isotan wire could have absorbed enough to change its behavior in the very first test.

More to come as it happens.  Stay tuned.