On Dec 9, 2011, at 9:40 AM, Jed Rothwell wrote:
Horace Heffner <hheff...@mtaonline.net> wrote:
The air gap the thermocouple extends out into is large. It is a
gap that is longitudinally between the nut and the manifold, and
radially between the nut outer surface . . .
I do not think so. The insulating material is flexible and fits
tightly. Also, the TC is against the flat surface of the nut,
I don't think so. The wire is against the nut, but it is not clear
the thermocouple tip is.
Here is another view of the thermocouple tip after the insulation was
removed. You can see it extends out beyond the nut, even though the
wire is bent upwards at the time of the photo.
http://lenr.qumbu.com/lenr_spicepics/111010_1C_crop.png
Here is photo of manifold with thermocouple removed. Air space is
probably about 5 mm deep, 2 cm wide? Also threads prevent firm wide
area contact.
http://lenr.qumbu.com/lenr_spicepics/111010_2_crop.jpg
Photos are from Alan Fletcher's site, the page with the nifty FEA
simulations:
http://lenr.qumbu.com/rossi_ecat_oct11_spice.php
and probably it is snugly covered on all sides.
HOWEVER, if you think this is a concern, we can test for it. We can
make a tent as large as you like, and see if it makes a measurable
difference.
The problem is simulating the nature of the manifold, with its very
high thermal conductivity and large contact area between hot and cold
sides. Taping together two hoses does not do this.
The string tent I made is probably bigger than anything in your
description of Rossi's setup. Also my string tent had a cold water
pipe running through it with lots of 16°C water flowing through, 1
cm away from the TC. That seems more extreme than what you are
proposing.
Heckert can also test for this with some insulation.
- Jed
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
