Rossi Lugano/early demo's revisited. (technical)

LDM ,

I will go over the spreadsheet, as well as the one before, soon.

I have been a bit distracted by the SK presentation and the resurrection of Doral, but that will soon pass.

BTW, I think that I have the world record for highest total emissivity conflated with IR measurement spectral emissivity fake COP. I challenge the rest world to beat it. (4.8 “COP”, using the Lugano Protocol). I think a 5 can be done with minor difficulty. 6 will take sone serious attention to details. Gold medal at the COPlylimpics!!! Yay!

Quote from LDM

This is one of the strongest indications that the Lugano dummy run temperatures where measured correctly and thus where not inflated.

Interesting.

I imagine that the Dummy has to be pretty close to reality, otherwise the Professors would have started diagnosing the problem right away.

The method they ended up using seemed to come up with reasonable numbers, and off they went.

However, the report explicitly goes through the inflation explanation and demonstrates it fully in action with several tables.

Note that the overall uncertainty estimated for the Dummy in the Lugano report is fairly generous.

Quote from LDM

Lugano ECAT convection correction

Due to the close spacing of the ribs of the Lugano ECAT, the convective heat transfer of the ribs is less effective. Thus there needs to be applied a correction to the calculated convective heat transfer of the ribs.

Without a correction the convective heat transfer is calculated based on the calculated convective heat transfer coefficient for the base tube with a diameter of 20 mm.

The convected power is then calculated by multiplying the convective heat transfer coefficient of the tube by the area of the fins and the difference temperature of the surface and the ambient temperature. The formula :

Q = h x Af x (Ts - Ta)

---------Q--------The power

---------Af-------The area of the fins

---------Ts-------Temperature of the surface

---------Ta-------Ambient temperature

However due to the fins being close to each other and their respective convective heat flows interacting, the convective heat transfer will be less effective and will result in a lower convected power.

Evaluating the above formula it means that the convective heat transfer coefficient has a lower value then one would expect when calculating it based on a bare tube. (which is the basis for the calculation in the Lugano report). The question now is how to determine the correct value of the convective heat transfer coefficient for a finned area as used on the Lugano ECAT.

The method followed was to calculate with the CFD software the convected power for two different section lengths of a finned area, the second section having halve the length of the first section.

The sections where simulated with a temperature of 445 degree C and an environmental temperature of 21 degree C.

Subtracting from the power of the longer section the power of the halve section yields the power of a halve section.

Since for both simulated sections the convected power of the sides at the ends is equal, this power of the sides is then automaticcaly removed by the subtraction and only the power of the finned area is calculated in this way.

Deviding the calculated convected power of the halve section by the fin area of the halve section and by the difference between section temperature and ambient temperature gives the convective heat transfer coefficient.

This convective heat transfer coefficient obtained in this way was found to have a value of 9.99

Since the value for a bare tube of 20mm diameter, tube temperature of 445 degree C and an ambient temperature of 21 degree C is 13.28 the convective heat correction factor becomes :

-------------------------Correction factor = 9.99/13.28 = .752

The conclusion is that due to having the fins next to each other without additional spacing in between, the convective heat transfer of the finned area is lower then one would expect based on the calculation in the Lugano report.

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I felt the need to drag this out and go over it a bit more.

It seems wrong that the ribs reduce the effective convection as compared to a regular cylinder (no ribs).

How does the above Correction Factor method compare with a Fin Effectiveness factor (which compares the fin base area to the bare tube area)?

Dewey Weaver ,

Interesting. Probably we can't do much with info that except frown at this point.

LDM ,

Alright, got myself back up to speed.

It looks to me like your 0.752 Correction Factor is roughly equivalent to a Fin Effectiveness of about 1.57 .

Quote from LDM

Was the Lugano broadband emissivity iteration done on the Optris ?

From the text written in the Luagano report it has been concluded that broadband emissivities where used on the Optris and thus the measured temperatures where inflated.

The Lugano report describes in detail how using an iterative procedure which uses emissivities from the broadband emissivity curve of alumina is used to arrive at the temperature and emissivity used.

It has been assumed that this procedure was done on the Optris and if this has been the case then this would have led to inflated temperatures.

On the other hand we have some indications that this has not been true.

The following investigations contradict the broad band emissivity use on the Optris :

1. Evaluation of the Lugano dummy run

For a non inflated dummy run the difference between applied power and calculated power form radiation and convection was investigated in post #393.

The result was that there was a difference between applied and calculated power of 1.6 %

For a dummy run with inflated temperatures the difference between the powers was -13.5 % (see post #424)

Since the error for a non inflated dummy run is much less then for an inflated one this indicates that the temperatures of the dummy run might not have been inflated.

2. FEM simulation of the Lugano ECAT

Using thermal finite element simulation on a model of the Luagano ECAT we see that the simulated temperatures are quite near those of the reported (Non inflated) temperatures , an other indication that the reported temperatures of the dummy run where correct (See post #465)

3. Evaluation of the power distribution

Comparing the powers dissipated in the rods, the end caps and the ribbed area of the ECAT with the powers dissipated by the heating wires in those sections revealed that for a non inflated dummy run there are several close matches, but there are no close matches for an inflated dummy run. (See post #543)

So there are doubts if what has been concluded from the written text in the Lugano report, that broadband emissivities where used on the Optris, is correct.

So I decided to repeat the different emissivity settings of the iterations shown in the Lugano report with the Optris software itself.

As input the dogbone2_cal_full.ravi file from the second MFMP dogbone thermal test was used with the Lugano style profile for the different measurement areas.

I used the temperature of measurement section 10 with an emissivity setting of 1.

Also the background temperature was decreased from 23 degree C to the 21 degree C as reported in the Lugano report.

The file was then started and then stopped at 24 minutes and 07 seconds at which time the temperature of section 10 was 366.5 degree C, almost the same temperature as the starting temperature of the first iteration in the Lugano report.

Then for all broadband emissivities used during the iterations shown in the Lugano report the Optris temperatures where determined by changing the emissivities with the Optris PI connect software.

The tabulated values together with those reported in the Lugano report are given in the following table :

Emissivity----------Temperatures------------Temperatures

---------------------Lugano iteration----------Optris iteration

----1.00-------------------366.6------------------------366.5

----0.76-------------------426.6------------------------432.1

----0.71-------------------443.1------------------------450.3

----0.69-------------------450.3------------------------458.3

----0.68-------------------454.0------------------------462.4

----0.62-------------------478.3------------------------489.4

----0.50-------------------541.2------------------------559.7

As can be seen there is a difference between the values reported in the Lugano report and those obtained when changing the emissivities on the Optris.

This difference becomes larger for lower emissivity values. For the lowest used emissivity of .5 the difference is 18.5 degree C.

Because the temperatures reported in the Lugano report are different from those obtained with the Optris software this leads to the conclusion that the iteration proces as outlined in the Lugano report can not have taken place with the Optris.

Thus it is also not likely that broadband emissivities in the Lugano report where used with the Optris.This is in agreement with points 1, 2 and 3 above.

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I can confirm that your above Optris conversions agree closely when I tried it using the .RAVI file suggested.

You may have noted that the emissivity adjustment required to align the Optris-DB2 values to the Lugano numbers is only about an increase of 0.02, but ranges from 0.015 to 0.026 from E=0.76 to E= 0.5 .

Unfortunately, when using the Padua Reheat 620 C file, I get different conversion numbers, as below:

Emissivity----------Temperatures------------Temperatures-----------E adjustment to match Lugano

---------------------Lugano iteration----------Optris iteration-Padua

----1.00-------------------366.6------------------------366.5----------------------- 0

----0.76-------------------426.6------------------------429.3---------------------- +0.009

----0.71-------------------443.1------------------------446.7---------------------- +0.01

----0.69-------------------450.3------------------------454.3---------------------- +0.01

----0.68-------------------454.0------------------------458.2---------------------- +0.011

----0.62-------------------478.3------------------------483.9---------------------- +0.012

----0.50-------------------541.2------------------------550.4---------------------- +0.014

The adjustment here required to match the Lugano temperatures is almost exactly half of that required for the DB2 file.

The main differences between the Padua reheat and the DB2 Optris settings are the 150 - 900 C calibration zone rather than 200 - 1500 C zone, and the Optris bolometer emissivity setting of 0.95 instead of 1.0 . 450 C is almost in the middle of this calibration range, so it is the ideal range for this temperature.

I note also that retroactively setting the background temperature or camera bolometer emissivity makes zero difference to the calculations the Optris performs on a stored .RAVI file. The original values are retained, as they are a critical part of the primary measurements.

Based on the above numbers, I suggest that the Optris Device emissivity was set to 0.9 for the Lugano test. (Alternately the Device Transmissivity setting may have been changed).

(The Optris fixed bolometer setting is different from the measurement area emissivity settings, and is located in the software Device settings folder, along with transmissivity settings, background settings etc.)

That should result in correct conversions from one camera emissivity to another that are consistent with the Lugano report Table 2a and 2b.

It may also explain the variances noted for the dummy.

Dewey Weaver ,

Are any of the original Lugano Optris .RAVI files available?

Especially for the Dummy run, but any of the original files would be useful.

LDM ,

I also yesterday tested the emissivity conversions using the GS5.3 .ravi files. In this case the Device emissivity was set at 0.95 and the calibration was for the 200 - 1500 C range. The results were similar to the Padua reheat one I did above, but slightly higher, typically by 1 C.

The reason that being in the middle of the calibration range is important is that the values are well inside the calibration range. This is always the ideal measurement range whenever possible in almost all systems. It is hard to say how important that is with the Optris, but one can assume that since there are different temperature calibration ranges that some error creeps in near the edges of a given range that are less in a range that the temperature/radiance is more centered in. Therefore I would say that emissivity-temperature translations done in the more centered range are more likely to be better than ones near the edge of the temperature range. (Would you prefer to take you own temperature to test for a fever with a thermometer that starts at 35 C and goes to 500 C, or one that starts at 20 C and goes to 50 C?)

Anyways, the general idea was to test the emissivity-temperature translations to see how variable they are. And they are variable, depending on something. It is a good point that the translations don’t seem to match the report values, and there should be a good reason for it.

I think it is strange that the Device emissivity setting has an effect on the measurement boxes, however. That does seem to defeat the purpose. The Device emissivity and transmissivity setting is usually altered by a link to an outside system, like a factory computer that can change the emissivity required for some process need, like liquid vs solid targets, etc. (The transmissivity setting being used for windows or lenses interfering with the direct Optris view.)

The other reason I was testing the emissivity adjustments required to match the Lugano temperature-emissivity translations is that I wanted to see if it was a constant shift, or as it is in this case, a non-linear adjustment. This helps define the source of the difference between our tests with Optris software and the the Lugano results that are posted in the report. The small power law adjustment suggests a minor global difference in the way radiant power is being measured from what we are doing.

I admit that the Device emissivity adjustment seems to be unlikely to be causing the difference, (since the measurement boxes should be independent), but the Device Transmissivity adjustment is quite possible. I think that the effect of a transmissivity adjustment can be evaluated mathematically to compare to the differences we see, and whether it is possibly the culprit. A lens transmissivity adjustment should be equivalent to a bolometer emissivity adjustment. The fact that the calibration range +/- Device emissivity change seems to alter the emissivity difference between the Lugano and our own emissivity-temperature translations linearly, to a power law slope emissivity difference, suggests the answers are to be found in the way the device is “seeing” the radiated heat.

It would be ideal if an owner of an Optris camera would simply film an object at 366 C , E measurement box = 1, and make a few short films with the transmissivity setting changed (1.0, 0.95, 0.9, 0.8) and the separately the Device emissivity changed (1.0, 0.95, 0.9, 0.8) so the effects of the changes can be considered. Once we enable our Optris software to do the temperature-emissivity translations the same as demonstrated in tables 2a and 2b, we can be more confident in what the higher temperatures were doing.

Clearly the Optris calibration range is important. Consider the data below. Although there are minor differences achievable due to mixing hot and cold pixels within a measurement area (emissivity changed here), in general the emissivity-temperature translations are consistent within calibration ranges (150-900 C or 200-1500 C).

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Cleaned up that plot a bit...

Might be neat to see what happens in the 0-250 C calibration range. (If it can actually go significantly higher than 250 C in that calibration range, that is.)

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Edit. All new translations begin with a measurement box at 366.6 C or 366.5 C, set at an emissivity of 1. Lugano line is from the report Table 2a and 2b recursive method demonstration, page 15.

For what it is worth, Optris claims the accuracy is +/- 2 C or +/- 2% , whichever is greater.

Quote from [email protected]

This is really interesting information. Does it prove that the Optris device was easy to spoof, that it's so complicated that 7 scientists misused it? Because this could become valuable information in a lawsuit against the 7 scientists who published their information and I know of some people who moved money into investments on the basis of that report. It could make Optris legally liable for the losses incurred.

Once they file the lawsuit and use your information as the basis for moving against Optris, there could be money in it for you as consultants, that kind of thing. But if you're just playing around on a Playground, it would be easy for a counter deposition to show that you really weren't serious about this.

Why did it take several years to come up with this? Is it real expensive, or is it difficult to generate this spoof?

Like any equipment there is a right way and a whole bunch of wrong ways to use it. The Optris can be “spoofed” a whole bunch of ways, but spoofing people is a bit trickier. In the case of a group of people watching/using the Optris the wrong way must look like the right way in order to not be discovered to be wrong.

In this case the error is substituting the Total normal emissivity (this is a single emissivity value that is equivalent to the integrated emissivity for each wavelength entire IR spectrum for a material, which in this case is alumina) for the camera emissivity setting necessary for the IR camera spectral sensitivity band, which just is a tiny part of the full IR spectrum. The IR camera does not see the entire IR spectrum, just a small window of it. So the emissivity setting for the camera is not the same as the Total emissivity. The Total emissivity value is correctly used and necessary for calculating the radiant Output power, however.

The camera emissivity setting is only used for the IR camera/pyrometer in order to report the correct temperature of the item, and is not used for calculating power. There are several IR detection bands commonly used for IR cameras and pyrometers, and depending on the shape of the emissivty profile over the entire IR spectrum, the different detection bands could have wildly different camera/pyrometer emissivity settings for the same object. All of these could be different from the total emissivity value. For greybody and blackbody objects, the emissivity is the same at all wavelengths, and in that case the camera settings would be the same for all detection bands and the same as the Total emissivity value used separately for calculating radiant power. This can be a complicated subject and I don’t want to write a book on the explanation now if it can be avoided.

Anyway, calibration is suggested by Optris (and all IR camera/pyrometer manufacturers) to ensure the IR camera/pyrometer is giving correct temperature information. Textbook values and chart summaries are a guide, not the law, about what emissivity value the IR camera/pyrometer needs in specific cases. A positive temperature error is multiplied 4 times when calculating power, and vice versa. This means that the IR camera/pyrometer can be remarkably accurate when calibrated properly since the device measures radiant power and derives a temperature as a result of 4th root of measured radiant power.

The Lugano device Dummy was not operated to the temperature levels reported for the Active period. The emissivity problem would have shown up for sure if it had. In fact, I have shown that at about 450 C is where the 4th power really starts kicking in compared to a real dummy unit. (The T⁴ difference starts really going logarithmic at temperatures above 450 C relative to a real dummy temperature. This means that in Lugano the Dummy, even with wrong emissivity values used for the Optris, did not greatly differ from the power expected for the Dummy. Close enough to explain away the discrepancy in measurement uncertainty. At about 800 C the discrepancy in the Dummy power compared to the input power would have been very noticeable. Unfortunately about 450 C (wrong emissivity used) is as high a reported temperature as the Dummy was operated.

The MFMP Dogbone experiments actually showed this effect, years ago, but it was not demonstrated to the level that it might have been. If all the Optris measurement boxes for the Dogbone are set to the emissivity settings from Plot 1, Lugano report, as was done at Lugano, and the radiant power calculated as done in the Lugano report, the MFMP Dogbone would have shown a COP of 3.8 (or something like that). The MFMP data and Optris files are there so the public can finish the job, but this doesn’t show up on any video stream so the public just didn’t notice it, or even ignored those that did do the final calculations. (I will have to find my spreadsheet to see what I actually came up with for Dogbone Lugano Style COP.)

A few notes on "An Indication of..." Levi et al 2012 March Test part.

(I will add notes as I go over this report again)

The length used in calculation [10] is 35 cm, rather than 33 cm described for the ecat length. This seems to be so that the 5 area sections can be 7 cm long. The extra adds roughly 42 W to the dummy output, however, due to 56.5 cm² being added to the area. Subtracting the 42 W from the calculated power output puts the dummy about 119 W short of the reported input. Adding the final 17 W breech area power in (not evaluated yet), leads to a ~100 W shortfall for the dummy combined radiant and convective power.

The report assumes that the total emissivity for power calculation is the same as the Optris emissivity setting. Hard to say how wrong this is. Might be close. Might not be.

0.8 to 0.9 total emissivity seems to be typical for dark/high E enamel paint. (Using a total E of 0.95 gives a decent result)

Trying to hold the Cylinder at 366.6 C E= 1.0 is hard.

Testing to see if a saved temperature can have the emissivity changed...