The Incandescent W Experiment
Run 3 - 20AUG98
For Run 3 we removed the 1 ohm series resistor and changed the capacitors in the calorimeter enclosure to 200 mfd of electrolyticd in parallel with a 1 mfd mylar and a .01 mfd ceramic. This arrangement produced very satisfactory suppression of high-frequency noise at the power analyzer.
We used the electrolyte from Run 2.
We employed the 1/4" dia Teflon shield around the W rod again and this time we started with about 2 cm of the rod exposed.
Here you see the screen output from Run 3 in its native DOS-like form. The run began with a 1 hour baseline, followed by a 1 hour electrolysis warm-up at a Pin of about 115 watts.
At 2.4 hours we turned up the voltage to 150 volts to invoke the incandescent mode. Pin rose to about 160 watts and then more-or-less steadily declined as the cathode eroded away over the next 5 hours.
At about 3.6 hours, something happened inside the cell which caused the current (Icell) to drop noticeably with a corresponding drop in Pin. Possibly a portion of the eroding W cathode fell off.
Throughout the incandescent portion of this run, the Pout trace faithfully follows the Pin trace indicating no sign of significant excess heat.
In this plot, as in the one from Run 2, the Pout values have been amended by adding 1.48*Icell to them.
As it turns out, this isn't exactly the right thing to do...but the resulting errors are quite small on the power scale involved. Our power analyzer reports RMS current when queried and this is what is plotted as the Icell trace. What should be used for the gas flow calculations and Pout corrections is the average cell current. In the case of the rather spiky currents in this experiment, RMS current can be quite a bit higher than average current. We observed it as much as 1.4 times higher than average current (as monitored by a Fluke 87 averaging the voltage drop across a precision non-inductive 1 ohm resistor in the circuit). For sine waves, RMS current is 1.1 times higher than average current.
All of the gas flow measurements reported earlier have suffered from the fact that we used the RMS current to calculate the expected gas flow. We should have used the average current and that would have predicted lower gas flows. We will explore these gas flow measurements carefully in Run 4.
Here's a photo of the remains of the W rod after this run. The white candle-like thing is the 1/4" dia Teflon rod that surrounds the rod. About 4 mm of rod is protruding from the Teflon and you can see how severely it is eroded (it started out protruding 2 cm).