I think it is not necessary to test something that is known and expected from theory and experience. If there is no thermal flow, then there are no temperature differences, this is known from physics. So especially when the measurment location is wrapped with thermal isolation a thermoelement fitted on a tube or on a hose will measure the water temperature. The only necessary condition for this is: the thermal coupling to the water must be stronger than the thermal coupling to environment.
It is necessary to think about unexpected effects: It is clear, in Rossis setup there was a thermal flow and an unwanted temperature difference close to the thermoelement. If the steam inlet was 100 degree and the water outlet was 20 degree then inbetween in the middle symmetry point the temperature MUST be (100+20)/2 = 60 degrees. This is simple to see from the symmetry. This 60 degree location was definitely too close to the thermoelement. It is a waste of time to discuss this, because a skilled engineer would easily recognize and would avoid such a unclear situation. It is also clear, a thermoelement must not have /multiple/ undefined and unknown electrical contact to the environment in a multichannel measurement system. Its a waste of time to discuss this, because it can be easily avoided. Best regards, Peter ----- Original Nachricht ---- Von: Jed Rothwell <[email protected]> An: [email protected] Datum: 08.12.2011 00:04 Betreff: [Vo]:Will tests surface mounted thermocouples on pipe > I wrote: > > > > Try placing at thermocouple on a hot pipe, in various spots, under > various > > covers. You will find the differences are insignificant. > > > > I did this years ago, working at Hydrodynamics. I happen to have a nice > dual input thermocouple, with a T1 - T2 mode, so I will try it again with a > copper hot water pipe, with and without insulation and so on. I will do > this under the kitchen sink. Varying water temperatures do not matter > because I am looking for a difference between T1 and T1 (when they are > mounted differently), and the response is quick. > > I have insulated all of the hot water pipes in my house foam pipe > insulation. Look it up at Lowe's. It works remarkably well. Anyway, I'll > try it with and without that, in air, under bubble wrap and a few other > ways. > > I have different kinds of probes too. I use a shielded probe for cooking > turkey. I'll just use the regular ones for this test. > > I can compare the actual fluid temp to the pipe temp if you like. I'll bet > it is the same to within 0.3 deg C. > > You people should do stuff like this, instead of blabbing for weeks at a > time about magic pots full of water that do not cool down. > > - Jed >
