On 2012-12-13 03:29, Craig wrote:
This is so strange. I set the data in View Test Celani Cell #2, found here:
http://data.hugnetlab.com/
to view back 4 hours. Then I selected only P_Xs Low. Notice that the
excess power is oscillating between 4 watts and 8 watts, in a very
precise rhythm, with each wave appearing to have the same shape, and
with each wave lasting about an hour. I also see that the wave appears
to be tapering with the lows becoming higher and the heights become
lower. There also seems to be a correlation with T_Ambient, but why?
Whatever this is, it didn't happen with the previous overnight run with
power applied to the inert wire (and the active wire partially loaded,
in hydrogen atmosphere). This is a user-submitted image from the MFMP
blog showing it:
http://i.imgur.com/bB383.png
(note that "Power (Red)" actually shows W instead of bar)
From 2012-12-12 00:00 to about 10:00, external glass temperature (under
50W of indirect heating) didn't seem to fluctuate very much with ambient
temperature. However with direct heating (48W) it does quite much.
The main difference between those two runs is that the one with indirect
heating had a starting hydrogen pressure of 2 bar (which increase with
heat, of course), while the latter ones started at 1 bar, probably
offering less thermal inertia (but still not explaining how glass
temperature variations can be larger than ambient ones, assuming that
these are the ones which drive them).
Cheers,
S.A.
