We are in a phase where we are developing and testing our methods before we test the next active Celani Wire. Per some excellent suggestions from our followers we are trying several new little experiments while we work towards some calorimetry also.
Stepping up and down
First, we are testing a new way of doing the calibration where we step the power up and then back down again. This is simple and easy to do and will help determine if the cell was at adequate equilibrium for the calibration test. It was suggested by Ed Storms. The results look like this:
When we plotted the upgoing curve vs the downgoing curve and found them to overlap pretty closely. To see the difference, we subtracted one set of points from the other, and got the following graph.
Here is the resulting data set in an xls format stored in google drive: https://docs.google.com/open?id=0ByUU8sU37DYsbVRLRnFyQ2JMODg
Better thermal connection to the glass:
Second, we are trying to enhance the validity of the temperature measurements. Towards this end, we took a small piece of aluminum (roughly 12mm X 36mm X 2.0mm), rolled it to match the glass, and carved a groove for the thermocouple tip to fit into.
Then we installed it on the glass with a little thermal grease under it and some some kapton tape over it. That should make some good thermal contact. Too bad we can't do that inside the glass, too.
Third, more temperatures sensors to explore more about the ambient
Then we also added more temperature sensors. Due to the limitations of the number of columns in the instrumentation software and the fact that we don't know if we'll keep these sensors, we put them in a different test. That test should be available in the data viewer today.
- T_A1 - Left side of air stream in vent hood
- T_A2 Middle of air stream in vent hood
- T_A3 - Right side of air stream in vent hood
- T_G1 - Exterior of glass on the left side (plumbing side)
- T_G2 - Exterior of glass in the middle
- T_G3 - Exterior of glass on the right side
- T_F1 - Middle of the flange on the plumbing side
- T_F2 - Middle of the flange on right side
Look for the range of variation in each part of the air stream. The sensors may have slight offsets. I guess we'll see.
Look for the variation of the temperatures on the glass and the range of noise on each one. Compare that to T_glassout which is now under a piece of aluminum with thermal grease between it and the glass.
Look for the slope of the temperatures on the flanges when the glass looks constant - expect different time constants
Results of Pressure Sweeps at a (mostly) Constant Power
The violet line was a sweep done with the new borosillicate cell with Macor ceramic wire supports. The orange line and light blue line below are with the insulation at the ends of the cell. The orange line is at 48 W and the light blue line is 47W. It showed a tiny amount of improvement in the slope, but definitely shows a trend for the temperature to rise as the pressure decreases. There are still some differences in the geometry between our cell and Celani's but I was expecting the insulation we put in to make more of a difference than it did. I don't really know why the T_glassout sensor seemed to read lower after the insulation was in place, though.
When we divide by the input power, we get a slightly smoother shape. It shows the two runs after the insulation was in place to behave very similarly, but shows the other run in violet to be of a significantly different baseline.
We have been advised to try to mount the cell in a vertical orientation in order to facilitate more consistent convection currents on the inside of the glass. We are going to try to figure out how to do that next.
From the Euro Team: As the team in Switzerland wait for the Celani wire in the EU cell to de-load, we see Nicolas working on a Mizuno type cell and Mathieu talking to Dr. Edmond Storms who is offering his assistance to the project.
With our Euro Cell, we are trying to unload hydrogen from Celani's wire as much as possible.
Unfortunately, we have broken the Nichrome wire 2 days ago.
So we cannot heat the wire indirectly, but rather by applying current into it while pumping the cell to vacuum.
As we do not want to put too much current in the wire, we wrapped a copper sheet around the cell to maximize the internal temperature.
Obviously, in these conditions we are far from the calibration baseline.
Therefor all excess heat data that you might have seen during the last 2 days are not correct.