The Incandescent W Experiment
Run 7 - 25AUG98
Run 7 was essentially a repeat of Run 6, this time with the cell temperature sensor connected from the start. We used fresh electrolyte (0.5M K2CO3) and exposed about 2 cm of the thoriated W rod for this run.
The run begins with the equilibration period necessary for an energy balance measurement. Note that Tcell leveled off at 40° C and that Pout closely approached zero before the input power (Pin) was applied. When the input power was applied, the energy integrals were reset to zero so that they would reflect only the energy balance for the actual run.
Again we applied warm-up electrolysis power for about 10 minutes until Tcell reached ~75° C. Then we turned up the voltage to about 175 volts, which caused an intense incandescence accompanied by a loud throbbing rumbling from the cell. Note that the input power reached >300 watts briefly (the power scale is -50 to +450 watts for this plot).
We left the cell voltage constant and Pin declined rapidly as the W rod eroded away. After 10 minutes or so, the rod was virtually gone and we turned off the input power. The calorimeter was allowed to run for another hour to collect all the heat energy stored in the cell.
The Ein and Eout traces tell the remainder of the story. As in Run 6, at the very end of the run, Eout is about 2.5% lower than Ein. This is a relatively small error but we are still surprised by it. It is possible that this discrepancy is a result of the anomalously high gas evolution rate from the cell during incandescent operation. We measured 4.8 times more gas evolving from the cell than expected from ordinary electrolysis during this run!!!
Thanks to the excellent contributions of our colleagues on the Vortex-L Internet discussion group, we will now endeavor to analyze this "excess gas" phenomenon.
By the way, we continue to employ capacitors only across the cell, which are located inside the calorimeter enclosure. As you can see from these scope traces, taken during incandescent mode in Run 7, the current (lower trace) is definitely erratic but it is free of the very high frequency components that tend to cause difficulty with electrical measurements.
Comments and suggestions are welcome.