Clearance Items

  • @ JedRothwell,

    The fact that I am quoted in a document is no indication that I read that document.


    Which document are you talking about?


    The subject of your previous reply (*) was a comment of mine (1), which was the last thing quoted by you. Immediately thereafter you did write "I have forgotten, or I never read that."


    I just reminded you that for sure you did read my comment (1), because you quoted it in your reply (2).


    Unless you are implying that you are able to reply a comment, without reading its contents!


    (*) Clearance Items

    (1) Jed Rothwell on an Unpublished E-Cat Test Report that “Looks Like it Worked”

    (2) Jed Rothwell on an Unpublished E-Cat Test Report that “Looks Like it Worked”

  • @ bocijn,


    Sounds very much like prior bias to me. did you actually read it?


    If you refer to one of the two hot-cat reports signed by Levi, the Ferrara's and the Lugano's reports, yes, I read them both, just one time, immediately after their respective release. In doing that I had for sure a strong prior bias, a negative one, with respect to their leading author, due to the prior examination of his 2011 report on the calorimetry of the Bologna's demo.


    What mostly struck me in the hot-cat reports was the adoption of a calorimetry technique based on the Stefan-Boltzmann's law. This method was already used by Celani and, after he presented his results in mid 2012, I already had the opportunity to see how it allows to exponentially multiply the effect of any mismeasurement.


    So, I decided not to waste my time any more in examining those reports.


  • Interesting that Celani used this same method. it is in fact perfectly good when used with surfaces that approximate grey bodies, or when properly calibrated at temperature. It is just that alumina is unusually (strikingly) temperature dependent in its total emissivity and has strongly non-grey-body characteristics that hit IR temperature measurement particularly badly.


    If Celani followed good practice IR measurement protocol, calibrating surface temperature against camera reading at all the temperatures used, I see no problem using this method.


    You could say that because it is indirect it requires a bit more care to get right than many other techniques, especially because the effective radiant surface area requires some care when estimating, with proper accounting for self-absorption and re-radiation. That estimate again needs at temperature control, or very great care.

  • I think the point that Ascoli was making (an obvious one) is that the measurement is one of temperature and the calculation of power and energy is a fourth power function of the temperature. Thus, any small error along the way, from the thermal camera itself or because of errors in calibration or emissivity assumptions, those errors are magnified to their fourth power in the result. It is a shitty method, in fact, if you have anything else. And, as I noted many times before, there is something else MUCH better -- a fluid cooled calorimeter which can be operated at the same temps as the hot cat,


    https://gsvit.wordpress.com/20…te-calorimetria-a-flusso/ (use Google translate, it works fine with this paper)


    Finally, again it needs to be noted, to prove that Rossi and Levi really have a discovery instead of a scam, all that is necessary is to rerun the experiment which gave the best results ever for an ecat -- the one by Levi which, sadly, he refused to give raw data for and refused even Dr. Brian Josephson email request to repeat with proper calibration and documentation. Odd that Levi would do that and not even reply to Josephson, don't you think?


    http://www.nyteknik.se/nyheter…energi/article3108242.ece


    IMO, all of the above casts huge doubts about Levi's credibility. If you think not, why not?


    I only recycle this because I keep hearing how persuasive the hot cat is and in particular, Levi's report about it. And that keeps getting recycled.


    Jed doesn't see any errors in Levi's results but other people see lots of POTENTIAL errors. And of course, nobody other than Levi, Rossi and perhaps Penon, had access to the power input system and the output power measurement devices. The credibility of the papers relies on the credibility of the participants.

  • @ THHuxleynew,


    Interesting that Celani used this same method.


    That's probably where the idea of switching from the LT Ecat to the HotCat came from.


    Quote

    it is in fact perfectly good when used with surfaces that approximate grey bodies, or when properly calibrated at temperature.


    A method that gives you an estimation of the heat flux proportional to the 4th power of temperature is only good for mixing up the results. Just the switching from a LT device and a mass flow calorimetry, to a HT device and such an indirect method, is quite suspicious.


    Quote


    If Celani followed good practice IR measurement protocol, calibrating surface temperature against camera reading at all the temperatures used, I see no problem using this method.


    Celani used a few thermocouples placed on the glass tube of his cell. His method was even more simple and direct than using an IR camera. Notwithstanding, MFMP got a lot of problems when they tried for a couple of years to replicate the Celani's results using his method. At the end they decided to build a mass flow calorimeter.

  • Alan Smith ,

    It is a pretty basic device, but the price point is great for the temperature range.


    Importantly, it can calculate temperatures as high as 1600 C, which is handy for basic emissivity tests. I find that the software in most IR thermometers limits the upper temperatures reported to the maximum of their rating. (ie, the Optris software only calculates temperatures as high as 1507 C with the 1500 C camera option).


    A device incapable of reporting as high as 1410 C of course will be of no use in testing (at least qualitatively) whether the correct emissivity user setting for a LWIR thermometer or camera when measuring a roughly 800 C alumina object is closer to, for example, 0.4 or to 0.95

  • I agree about price btw, there is nothing close to it, took me a lot of searching to find this bargain. ,Many similar-looking low temperature ones but this is the only high temperature version I have found.

    When you tested for the appropriate IR thermometer emissivity settings for alumina and for Durapot 810, what were your findings?

  • I haven't tried that IR thermometer yet on anything hotter than my stovetop.


    I haven't heated up anything for a while, but I'm going give it a go again soon.


    I have a 4-channel TC recorder and probably 3 TCs still in good shape.

    Just wound up a ~170 mm long, 6 mm diameter, 12 ohm Kanthal A1 heater coil, with a plan to uncoil one loop every ~39 mm, to make 4 parallel coils (wired still in series) into a roughly 5 cm square, 10 mm thick alumina block, once potted.

  • Post by omraut ().

    This post was deleted by Alan Smith ().