The Playground

rb0 ,

Clearly we have irreconcilable differences of opinion on the Optris emissivity and alumina, etc. We are at an impasse.

So let's move on to another subject for a fresh start.

Dewey once claimed that there was a little problem of a serial number on the water meter (AKA flowmeter).

Do you suppose that by serial number, he meant the actual serial number, or maybe instead the model number? (Since the reported (by Murray, Exhibit 5) model number seems so unsuitable for the required purpose).

Below are two images of the model specified by Murray, albeit the one used on the mW plant might not have used the steel cover and electric counter sending unit with convenient 100kg (~L) increments.

The flow rates on the label are as Murray described. Note there is both a model number tag and a serial number. If the model number was transcribed wrong by Murray, then perhaps a water meter that was operating within it's certified range was actually installed and used.

Lets not shuffle along to the next subject just yet.

Rbo - Didnt Rossi claim that IH made the Lugano reactors?

Sorry MrSS - no need to dabble in the hypothetical.

Since no one bit on the Lugano reactors question - they were made by IH in Raleigh with Durapot 810, which per Cotronics, has between 75% and 85% alumina powder in the cement, batch dependent. You then get to factor in another tidbit - the Lugano reactor was apparently painted in Lugano by either Rossi or one of the testers. Specific paint color, make and model unknown.

Painted?

Before or after the test?

Para - the reactor was painted before the test.

Dewey,

If it was high emittance paint, it won't do a whole lot to the camera readings (as adjusted to ε around 0.95), but would do weird things to the total power compared to using the alumina total emissivity.

Should run cooler, overall, than plain alumina, being a more effective radiator.

There are not a lot of high emittance paints/coatings available in off-white, but there are a few. (Visible color is a weak indicator of IR emissivity).

Noted Para - so much for the 99% pure alumina IR camera settings.

The Cotronics Durapot 810 is listed as being "tan" colored.

I notice that the rods seem to be tan, but not so the reactor, except in a patch on the RH side in the Lugano report photo with the scale.

Then there is problem is that if a high emittance paint was used, the total hemispherical emissivity will go up from around 0.4 to probably close to 0.8, making a COP close to 2 even with around 800°C with the camera emissivity adjusted to 0.95 .

Unless perhaps the Lugano device was painted with nearly pure alumina... explaining why it is white. An alumina coating would have to be thick, though, to have much effect on emissivity. At least 1.5 mm of alumina to become the dominant spectral emission source (optically thick enough), which seems not to be the case.

@Dewey,

The Lugano reactors were made by IH, but never pre-tested prior to providing them to the Swedes? Not even the ON/OFF mode? Seems kind of curious to provide such a mode if never tested before-hand by IH.

quotes are from rb0. #1509 above. I'm quoting nearly all of it.

rb0 - if you'd rather conduct a dialog in private with TC himself you could probably find his e-mail. He stated here that he e-mailed the Lugano authors with an early draft of his correction before going public. If not I bet the admins here can relay messages. When here TC always seemed willing to discuss matters, in private or public.

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In the Lugano paper itself is demonstrated that Allumina pipes have an emissivity much lower then the BB.

In that case it was possible for the group of scientists to measure the actual emissivity using reference dots.

The value obtained was compatible with the value of the total emissivity found in literature for pure Alumina the temperature of the pipes.

This is distraction tactics. No-one real is disputing the total emissivity figures in the Lugano report. TC uses them. They may not be precisely accurate, but are a decent approximation.

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There was at least another version around.

The version you are linking looks well printed..... but completely ill based.

No. There was not another version of the TC paper. Maybe you are confusing it with the Bob Higgins paper (which had pictures)? TC referenced Bob but did not follow him because Bob leaves out the key issue (he actually has a gap in his logic where the issue lies).

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You can't do a calculus like TC (? is the real author ) propose.

The TC paper does that (numerical integration). I can lead you through the theory, of the numerical code that does it, if you like? You saying "it cannot be done" when it has been done with the details included in the TC paper is absurd.

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First all the argument of the band emissivity is wrong ( Paradigmoia I have tried to explain that to you many times )

P and I agree 100%. And we have both educated you until you have gone away because unable to sustain a connected logical argument on the matter. Unfortunately the half-life of Forum retention of technical details is pretty small and maybe we need to redo this now. P has understandably lost patience - he has been doing the repeat explaining for quite a while.

I'll happily do this now. It is blindingly obvious that an IR camera that estimates temperature from IR output sensed in a specific band must depend on the emissivity in that band, not the emissivity in other bands. Since emissivity depends on spectral frequency you cannot work out other bands from the Optris band. Therefore the total emissivity (integrated over all frequencies and Planck curve for given temperature) cannot be enough. What do we need....? 1...2...3...

We need the band emissivity

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Second even if you would like to do so you would have to consider the actual band sensitivity of the camera vs wave length (i.e. light "color" in IR band ), that is not a flat ( constant ) function and depends on optics and sensor ( in fact each pixel is different ).

Good, now we are near to agreement. Yes, you need to consider the camera bolometer spectral characteristics. Do we need this exactly? Well, TC tried various spectra over the 8-13um range and you do get a difference in results, but it is not very large. That is because over most of this range Al2O3 has a high spectral emissivity so how this is weighted by the camera has a relatively small effect, especially when you include Planck weighting, I can lead you through the numerical calcs, or, if you have Python 2.7, You could try the code yourself, and see what happens with different assumptions about Optris non-flat sensitivity. TC used (in absense of other data) a constant value close enough to the generic IR bolometer spectral sensitivity curves referenced by Bob Higgins [1]. This is undoubtedly a source of error but for the reason above not large error. In any case your point here (correct, of all your many points the one I agree with) shows that the Levi et al method was clearly wrong.

[1] https://drive.google.com/file/…4cOM2Zl9FWDFWSUpXc0U/view

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I really think that diffusing this kind of false information could be against law in that case because of the ongoing trial, and I presume that any scientist who may have read that paper had thrown it in the bin in just few seconds.

Scientific disagreement is not against the law. Sometimes things are written that are just wrong, as in the original Lugano calculations. I would not say those authors have committed any crime and while persisting in wrong views is annoying it is unfortunately commonplace. We can all, when we do not engage in careful dialog with contrary views, be guilty of it.

I am offering to defend every sentence of the TC report (with the exception of the one very minor mistake).

Regards, THH

Quote from Dewey Weaver

Para - the reactor was painted before the test.

That is interesting! This is the Lugano reactor? Or the earlier Ferrara one which was painted black? if the paint is black body in the IR wavelength the TC adjusted temp calcs stay the same but maybe the output power changes.

Quote from Paradigmnoia

Then there is problem is that if a high emittance paint was used, the total hemispherical emissivity will go up from around 0.4 to probably close to 0.8, making a COP close to 2 even with around 800°C with the camera emissivity adjusted to 0.95 .

Agreed. If high emissivity and optically thick we would have COP=2! Redemption of the Lugano authors in sight? Except they claimed no paint and pure alumina surface.

Tom

Looks like NASA managed to get optically thick plasma sprayed alumina thicknesses as low as 0.5 mm.

https://ntrs.nasa.gov/archive/….nasa.gov/19780018205.pdf

Shane - no confusion. Off-white paint. We have the brand and product number.

We also have the same batch of Durapot 810 and a leftover virgin reactor from that production run. Planet Rossi may hear more about that later.

No comment on Levi having the material sample tested and coming back with 99% alumina except....say no more say no more.

Quote from Dewey Weaver

No comment on Levi having the material sample tested and coming back with 99% alumina except....say no more say no more.

Was the sample ground up?

99% alumina, 1% high emissivity paint?

I don't doubt the Bologna professors analysis of the material he rcvd and tested but it certainly was not a sample of the Durapot 810 Lugano reactor material which was / is between 75% and 85% alumina based cement. This one is not hard folks.