Am 09.12.2011 18:59, schrieb Jed Rothwell:
Peter Heckert<[email protected]> wrote:
The thermoelement on the tape has a bad contact to the metal and measures
preferrably the air temperature.
This is not a valid test. You have to cover up the thermocouples. Rossi did
not leave them open to the air.
I assume that under the surface of the insulation warm air can distribute.
Probably the air has the average temp of input and output. The
thermoelement would be exposed to this air even if it might be
separately glued on with adhesive tape, but not tightly, or if
glassfiber was between thermoelement and metal.
Remember, for this measurement in Rossis setup there was a typical
delta_t measured of 5 degrees. This means, 0.5 degrees is 10% error.
The problem would be avoided, if a reasonable delta_t of 30° would be
chosen. This is typical for domestic heat radiators and so this would
also give a nice customer-oriented demo.
rossi has missed this chance.
Of course leaving them open will pick up the air temperature. That is
obvious. Yesterday when I removed the foam pipe insulation, the temperature
dropped 1.4 to 3°C, even though the TC was still covered with adhesive
tape. It began fluctuating, no doubt due to air currents.
Putting a layer of tape under the TC in open air might well increase this
problem. You have put everything under insulation.
I see no point to testing for problems that Rossi cannot possibly have.
- Jed
