Re: [Vo]:Re: Regarding Rossi and NASA (+ some Piantelli news)
On Sep 28, 2011, at 12:20 PM, OrionWorks - Steven V Johnson wrote: Rizzi sez: ... I think that the end of the hoax is approaching. I doubt we are witnessing a hoax, though it's possible I am in error. Another thought came to mind in regards to the megawatt reactor design: Why for their first generation of "products" are they building a 1 MW module? Many have stated many times that a smaller less complicated configuration that generates a more modest amount of heat of say 10 - 50 kilowatts of energy would be more than sufficient to prove their point. One theory as to why the 1 MW reactors is being designed for prime time is to prove to prospective investors that the technology can be scaled up immediately. That may be true, but perhaps a more subtle point might be that by assembling a bunch of eCat cores under one hood the engineers increase their chances that at least a decent number of the individual reactors will work. Maybe there are far more individual eCat cores than what ought to be necessary in order to generate 1 MW of heat under the hood. Maye the engineers have discovered the fact that statistically speaking only about 50% - 75% of the individually assembled reactor cores work. I wonder if they have installed enough additional reactor cores to more-or-less guarantee that the entire module will, statistically speaking, generate at a minimum 1 Megawatts of heat. Just a thought... and I suspect it has already been raised by others here. Regards, Steven Vincent Johnson www.OrionWorks.com www.zazzle.com/orionworks Looking at the other side of the coin, the probability of catastrophic failure, suppose there is a 0.1% chance per hour one of the E-cats can blow up spreading steam throughout the container. There is thus a 0.999 probability of success, i.e. no explosion for one E-cat, operating for one hour.The probability that all 52 E- cats perform successfully for a 24 hour test period is then 0.999^ (52*24) = .287. That means there is a 71.3% chance of an explosion during a 24 hour test. The fact it is more difficult to manually monitor 53 E-cats than a single E-cat also means the probability a single E-cat of the 53 blows up in a given hour would be higher than it would be for that E- cat operated singly. It is not even clear facilities to monitor individual critical E-cat conditions, like internal pressure or flow, are present in the 1 MW E-cat. If no individual monitoring is feasible then the probability of individual failure in a given hour should be much larger than when independently operated. Then there is the feasibility of the 1 MW unit producing over a MW just from the huge thermal mass it has, even if all nuclear reactions are shut down. A significant back pressure due to the seam vent pipe being too small could reduce input water flow resulting in suddenly increased boil off of the water in the E-cats resulting in a catastrophic feedback loop and multiple E-cat explosion. The individual probabilities of failure can be made larger in a combined configuration due to additional shared parts. Best regards, Horace Heffner http://www.mtaonline.net/~hheffner/
[Vo]:H2 and O2 bubbles <.15 micrometer burn, damaging electrodes in AC electrolysis -- could complicate cold fusion devices: Rich Murray 2011.09.28
H2 and O2 bubbles <.15 micrometer burn, damaging electrodes in AC electrolysis -- could complicate cold fusion devices: Rich Murray 2011.09.28 [ Rough surfaces on electrodes and other components, with catalytic impurity concentrations and higher localized voltages and temperatures, may cause larger microbubbles to spontaneously combust, increasing surface damage and adding complex reaction products to the electrolyte, producing local heat and more catalytic deposits -- making a bubbling scientific witch's stew... ] http://www.physorg.com/news/2011-09-spontaneous-combustion-nanobubbles.html Spontaneous combustion in nanobubbles September 28, 2011 Enlarge [ black and white images ] Formation of bubbles at the electrodes during electrolysis (can be seen in a and b). Situations c, d, and e show the formation of both hydrogen and oxygen on the left, hydrogen alone in the middle and oxygen alone on the right. Situation e shows combustion taking place on the left. No bubbles can be seen on the electrodes. (PhysOrg.com) -- Nanometer-sized bubbles containing the gases hydrogen and oxygen can apparently combust spontaneously, although nothing happens in larger bubbles. For the first time, researchers at the University of Twente’s MESA+ Institute for Nanotechnology have demonstrated this spontaneous combustion in a publication in Physical Review E. They intend to use the phenomenon to construct a compact ultrasonic loudspeaker. The fact that a violent reaction takes place is already evident from the damage incurred by the electrodes with which the reaction is initiated. These electrodes are used to make hydrogen and oxygen by electrolysis, in the usual manner, in an ultra-small reaction chamber. If the plus and minus poles are continually alternated, tiny bubbles containing both gases arise. The frequency with which the poles are alternated determines the size of the bubbles: the higher the frequency, the smaller the bubbles. Combustion only takes place in bubbles that are smaller than 150 nanometres (a nanometre is a millionth of a millimetre); nothing happens in larger bubbles. Early experiments in microreactors also showed that nothing happened in larger bubbles; the heat can dissipate to the larger internal surface. Meters per second Researcher Vitaly Svetovoy was working on the construction of an actuator for rapidly building pressure when he came across this phenomenon. Such actuators are, for example, used in loudspeakers for ultrasonic frequencies undetectable by the human ear in the medical world. None of the mechanical techniques currently available are suitable for making a very compact loudspeaker of this kind and still achieving a 'deflection' of metres per second on this scale. Svetovoy thought, however, that it might be possible by building up pressure with bubbles. The problem was that the bubbles could be made very rapidly but that they did not disappear quickly enough. The combustion reaction that has now been demonstrated might solve this problem. But it causes other problems too, such as the damage to the electrodes. "That is what we now have to look at", Svetovoy said. This research was carried out by Prof. Miko Elwenspoek's Transducer Science and Technology group of the University of Twente's MESA+ Institute for Nanotechnology. The article 'Combustion of hydrogen-oxygen mixture in electrochemically generated nanobubbles' by Vitaly Svetovoy, Remko Sanders, Theo Lammerink and Miko Elwenspoek appeared in Physical Review E on 23 September 2011. Provided by University of Twente (news : web)
Re: [Vo]:Re: Regarding Rossi and NASA (+ some Piantelli news)
Rizzi sez: ... > I think that the end of the hoax is approaching. I doubt we are witnessing a hoax, though it's possible I am in error. Another thought came to mind in regards to the megawatt reactor design: Why for their first generation of "products" are they building a 1 MW module? Many have stated many times that a smaller less complicated configuration that generates a more modest amount of heat of say 10 - 50 kilowatts of energy would be more than sufficient to prove their point. One theory as to why the 1 MW reactors is being designed for prime time is to prove to prospective investors that the technology can be scaled up immediately. That may be true, but perhaps a more subtle point might be that by assembling a bunch of eCat cores under one hood the engineers increase their chances that at least a decent number of the individual reactors will work. Maybe there are far more individual eCat cores than what ought to be necessary in order to generate 1 MW of heat under the hood. Maye the engineers have discovered the fact that statistically speaking only about 50% - 75% of the individually assembled reactor cores work. I wonder if they have installed enough additional reactor cores to more-or-less guarantee that the entire module will, statistically speaking, generate at a minimum 1 Megawatts of heat. Just a thought... and I suspect it has already been raised by others here. Regards, Steven Vincent Johnson www.OrionWorks.com www.zazzle.com/orionworks
Re: [Vo]:Regarding Rossi and NASA (+ some Piantelli news)
On Wed, Sep 28, 2011 at 3:11 PM, Robert Leguillon wrote: > But, he only really achieved stability when it > WASN'T WORKING. By failing to do proper calorimetry and use proper > controls, he'd fooled himself into thinking it's running smoothly when it > isn't running at all. I agree that this is probably what is happening. The fact is that there is likely no stable operating point with his geometry. He needs a complete design team of multiple disciplined engineers to develop a working product. We can only hope that Defkalion has done just that with Rossi's reaction. T
RE: EXTERNAL: [Vo]:Regarding Rossi and NASA (+ some Piantelli news)
I didn't find the story discouraging so much as just pragmatic, Piantelli has papers, reproducible experiments and decades more experience than Rossi. Even Rossi's head start / foundation was built on Piantelli's research and any new efforts by NASA or other entities are much easier to justify based on Piantelli's research than Rossi's. Due diligence puts Piantelli over Rossi regarding risk mitigation. I still wish Rossi luck with his financial enterprise but it is going to take a national lab to finally understand and optimize this effect. -Original Message- From: Akira Shirakawa [mailto:shirakawa.ak...@gmail.com] Sent: Wednesday, September 28, 2011 2:00 PM To: vortex-l@eskimo.com Subject: EXTERNAL: [Vo]:Regarding Rossi and NASA (+ some Piantelli news) Hello Group, Have a read at Krivit's latest blog post here: NASA Advances Evaluation of Piantelli’s LENR Research Short URL: http://goo.gl/Ei9jW (which is quite interesting and I recommend to read it entirely, although that partially goes outside the scope of this thread). Excerpt from the end of the article: > On Sept. 5 and 6, a team comprising representatives from an investment group > and NASA visited Andrea Rossi’s showroom in Bologna. The team went there with > an explicit agreement about test parameters and opportunities to observe and > evaluate Rossi’s claims. They did not observe any positive results. This isn't very encouraging news. Assuming that Krivit's sources are correct, could this be the reason why Rossi is repeatedly denying any involvement with NASA? Or maybe it's Krivit's misinterpretation of the actual happenings instead? Cheers, S.A.
[Vo]:Re: Regarding Rossi and NASA (+ some Piantelli news)
>As was previously theorized, Rossi may have really been onto something. >Unfortunately, when the reaction occurs, it is difficult to keep stable; it >runs away and needs to be quenched. Robert, Rossi made 58 of “difficult to keep stable” modules and put together. If reaction is so instable, nobody will made a central. I think that the end of the hoax is approaching. From: Robert Leguillon Sent: Wednesday, September 28, 2011 9:11 PM To: vortex-l@eskimo.com Subject: RE: [Vo]:Regarding Rossi and NASA (+ some Piantelli news) My two cents: As was previously theorized, Rossi may have really been onto something. Unfortunately, when the reaction occurs, it is difficult to keep stable; it runs away and needs to be quenched. If you recall, the Defkalion rumors centered around a nonpayment from Defkalion until Rossi achieved stability. In an effort to "tame the cat", and "make it safe" he had tried to find a lower-power stable setup. But, he only really achieved stability when it WASN'T WORKING. By failing to do proper calorimetry and use proper controls, he'd fooled himself into thinking it's running smoothly when it isn't running at all. If Krivit's sources are correct (it is worth reading the entire NET article), NASA really sounds quite excited about LENR, and appears to have made great strides in successful replication. I just wish that they would publish their results openly. They successfully saw anomalous heat in 1989, but were afraid to admit it, until now: ""Tests conducted at NASA Glenn Research Center in 1989 and elsewhere consistently showed evidence of anomalous heat during loading and unloading deuterium into bulk palladium. At one time called “cold fusion,” now called “low-energy nuclear reactions” (LENR), such effects are now published in peer-reviewed journals and are gaining attention and mainstream respectability. The instrumentation expertise of NASA GRC is applied to improve the diagnostics for investigating the anomalous heat in LENR."" http://www.grc.nasa.gov/WWW/sensors/PhySen/research.htm But, Krivit may be onto something. The NASA site I've linked above has the following soon-to-be-link at the bottom. + Download presentation given at a LENR Workshop at NASA GRC in 2011 [available soon]. LENR looks to really be gaining attention. Andrea Rossi may be lost to history, if only by his own behavior. Donating to the World - Two Cents at a Time, R.L. ___ > Date: Wed, 28 Sep 2011 20:00:25 +0200 > From: shirakawa.ak...@gmail.com > To: vortex-l@eskimo.com > Subject: [Vo]:Regarding Rossi and NASA (+ some Piantelli news) > > Hello Group, > > Have a read at Krivit's latest blog post here: > > NASA Advances Evaluation of Piantelli’s LENR Research > Short URL: http://goo.gl/Ei9jW > > (which is quite interesting and I recommend to read it entirely, > although that partially goes outside the scope of this thread). > > Excerpt from the end of the article: > > > On Sept. 5 and 6, a team comprising representatives from an investment > > group and NASA visited Andrea Rossi’s showroom in Bologna. The team went > > there with an explicit agreement about test parameters and opportunities to > > observe and evaluate Rossi’s claims. They did not observe any positive > > results. > > This isn't very encouraging news. Assuming that Krivit's sources are > correct, could this be the reason why Rossi is repeatedly denying any > involvement with NASA? Or maybe it's Krivit's misinterpretation of the > actual happenings instead? > > Cheers, > S.A. >
RE: [Vo]:Regarding Rossi and NASA (+ some Piantelli news)
My two cents: As was previously theorized, Rossi may have really been onto something. Unfortunately, when the reaction occurs, it is difficult to keep stable; it runs away and needs to be quenched. If you recall, the Defkalion rumors centered around a nonpayment from Defkalion until Rossi achieved stability. In an effort to "tame the cat", and "make it safe" he had tried to find a lower-power stable setup. But, he only really achieved stability when it WASN'T WORKING. By failing to do proper calorimetry and use proper controls, he'd fooled himself into thinking it's running smoothly when it isn't running at all. If Krivit's sources are correct (it is worth reading the entire NET article), NASA really sounds quite excited about LENR, and appears to have made great strides in successful replication. I just wish that they would publish their results openly. They successfully saw anomalous heat in 1989, but were afraid to admit it, until now: ""Tests conducted at NASA Glenn Research Center in 1989 and elsewhere consistently showed evidence of anomalous heat during loading and unloading deuterium into bulk palladium. At one time called “cold fusion,” now called “low-energy nuclear reactions” (LENR), such effects are now published in peer-reviewed journals and are gaining attention and mainstream respectability. The instrumentation expertise of NASA GRC is applied to improve the diagnostics for investigating the anomalous heat in LENR."" http://www.grc.nasa.gov/WWW/sensors/PhySen/research.htm But, Krivit may be onto something. The NASA site I've linked above has the following soon-to-be-link at the bottom. + Download presentation given at a LENR Workshop at NASA GRC in 2011 [available soon]. LENR looks to really be gaining attention. Andrea Rossi may be lost to history, if only by his own behavior. Donating to the World - Two Cents at a Time, R.L. ___ > Date: Wed, 28 Sep 2011 20:00:25 +0200 > From: shirakawa.ak...@gmail.com > To: vortex-l@eskimo.com > Subject: [Vo]:Regarding Rossi and NASA (+ some Piantelli news) > > Hello Group, > > Have a read at Krivit's latest blog post here: > > NASA Advances Evaluation of Piantelli’s LENR Research > Short URL: http://goo.gl/Ei9jW > > (which is quite interesting and I recommend to read it entirely, > although that partially goes outside the scope of this thread). > > Excerpt from the end of the article: > > > On Sept. 5 and 6, a team comprising representatives from an investment > > group and NASA visited Andrea Rossi’s showroom in Bologna. The team went > > there with an explicit agreement about test parameters and opportunities to > > observe and evaluate Rossi’s claims. They did not observe any positive > > results. > > This isn't very encouraging news. Assuming that Krivit's sources are > correct, could this be the reason why Rossi is repeatedly denying any > involvement with NASA? Or maybe it's Krivit's misinterpretation of the > actual happenings instead? > > Cheers, > S.A. >
[Vo]:Regarding Rossi and NASA (+ some Piantelli news)
Hello Group, Have a read at Krivit's latest blog post here: NASA Advances Evaluation of Piantelli’s LENR Research Short URL: http://goo.gl/Ei9jW (which is quite interesting and I recommend to read it entirely, although that partially goes outside the scope of this thread). Excerpt from the end of the article: On Sept. 5 and 6, a team comprising representatives from an investment group and NASA visited Andrea Rossi’s showroom in Bologna. The team went there with an explicit agreement about test parameters and opportunities to observe and evaluate Rossi’s claims. They did not observe any positive results. This isn't very encouraging news. Assuming that Krivit's sources are correct, could this be the reason why Rossi is repeatedly denying any involvement with NASA? Or maybe it's Krivit's misinterpretation of the actual happenings instead? Cheers, S.A.
Re: [Vo]:It's the Big One
Sunspot 1302 is waning. I guess we avoided another Carrington Event: http://science.nasa.gov/science-news/science-at-nasa/2008/06may_carringtonflare/ But, a large EMP event is becomes more likely with nuclear proliferation: http://www.futurescience.com/X5DNA/X5DNA.html I guess that I am just spooked from the book I am reading: http://www.amazon.com/One-Second-After-William-Forstchen/dp/0765356864/ref=sr_1_1?s=books&ie=UTF8&qid=1317229664&sr=1-1 T On Tue, Sep 27, 2011 at 3:14 PM, Terry Blanton wrote: > http://www.dailymail.co.uk/sciencetech/article-2042428/Earth-cross-hairs-huge-solar-storm-caused-sunspot-1302.html > > "A sunspot, 62,000 miles across - so big it would dwarf the Earth - is > releasing gigantic solar flares that could in theory wreak havoc with > electrical communications ranging from handheld electronics such as > iPhones to sections of the power grid. > Nasa has detected two X-class solar eruptions from 1302 – the most > extreme possible – in the past week. One that occurred on September 24 > produced an amazing light show over England last night – but it’s far > from over, as the sunspot isn’t yet directly aligned with Earth. > > > > Ground everything! > > T > >
Re: [Vo]:Another cold fusion generator?
Terry sez: > Keshe is quite, er, eclectic! > >> http://keshefoundation.com/home.html >> >> http://www.keshefoundation.com/phpbb/viewtopic.php?f=2&t=229 I'd also add: A lot of talk. A lot of dreaming. But where's the beef? Regards Steven Vincent Johnson www.OrionWorks.com www.zazzle.com/orionworks
Re: [Vo]:Inexpensive steam/water calorimeter
When I say "precise method" I mean the inclusion of the specific data to be obtained, where it is obtained, and the formulas applied. You wrote: "Indeed, continuous experiments easiest way is to use enthalpy sensors, that gives as total enthalpy for any given moment. Even more simple is to measure the steam pressure inside E-Cat, because it gives directly the total enthalpy, but of course we need to first calibrate this kind of enthalpy sensors." There is no such thing as an actual enthalpy sensor. Only specific enthalpy is sensed. Only incremental enthalpies (delta H) of a system can be measured. To obtain energy of a mass of steam, relative to that mass at some temperature, you need to know the mass of the steam. The mass of an army tank differs from the mass of a small car. Measuring only pressure, or specific enthalpy, provides an insufficient amount of information. To obtain thermal power you need to know the mass flow. The water overflow is a significant part of the flow by volume, more than 2% in some cases by volume. This means the specific enthalpy of the steam is almost insignificant in those cases. If x is the liquid portion by volume, then x/((x+(1-x)*0.0006)) is the portion by mass. This gives the following table which I posted here last January: Liquid LiquidGas PortionPortion Portion by Volume by Mass by Mass - --- --- 0.000 0. 100.00 0.001 0.6252 0.3747 0.002 0.7695 0.2304 0.003 0.8337 0.1662 0.004 0.8700 0.1299 0.005 0.8933 0.1066 0.006 0.9095 0.0904 0.007 0.9215 0.0784 0.008 0.9307 0.0692 0.009 0.9380 0.0619 0.010 0.9439 0.0560 0.011 0.9488 0.0511 0.012 0.9529 0.0470 0.013 0.9564 0.0435 0.014 0.9594 0.0405 I consider the big deal about the definition of "steam quality" to be a red herring, a diversion from the important issues of measurement of the thermal power carried by the mass flow of a water steam mixture. Best regards, Horace Heffner http://www.mtaonline.net/~hheffner/ On Sep 27, 2011, at 9:16 PM, Jouni Valkonen wrote: First I would add to my previous message, that I think that Peter's method is more accurate than measuring pressure. That is because in order to find out correlation between pressure and enthalpy we need to do very careful calibration. In short run high accuracy may be difficult to archieve, but if experiment lasts for example 10 years continuously, then of course calibrating pressure sensor for enthalpy calculations will give great pay off. Horace wrote: « You have again not specified the precise method you would use. It would appear you have a case of missing variables. The principle missing variable is mass flow, m dot, which is best to isolate and measure directly. » Actually I have defined but it is so simple that you have probably missed it. First of course, we need to know that system is at equilibrium, i.e. water massflow in and massflow out are both matching. If water inflow rate varies a lot then calculations and calibrations are difficult, if system is overflowing. That means that for sure massflow must be known and it must be measured in calibration. But if system is a kettle boiler that does not overflow, then calibration is very easy. In industrial water boilers this is the most reasonable situation because this ensures high steam quality because we can easily superheat steam to remove that 1-2% natural wettness of steam. This reduces the corrosion. Superheating can also be considered in calculations so this does not reduce the accuracy of method. Pressure can be measured either directly with pressure sensor (easiest and most reliable and it is always available in pressure boilers.) or in kettle boilers boiling water temperature can be measured or last method is to measure steam temperature (this works only if steam is not superheated and is thus wet. I.e. steam quality must be measured, therefore this method is not universal). —Jouni On Sep 28, 2011 7:41 AM, "Horace Heffner" wrote: > > On Sep 27, 2011, at 9:35 AM, Jouni Valkonen wrote: > >> 2011/9/27 Peter Gluck : >>> The simplest solution is to use a Steam Water mixing valve,in >>> which the >>> heated mixture coming out from the demo is mixed with a constant >>> flow of >>> cold water, you can know the enthalpy performance in any moment. >> >> Indeed, continuous experiments easiest way is to use enthalpy sensors, >> that gives as total enthalpy for any given moment. Even more simple is >> to measure the steam pressure inside E-Cat, because it gives directly >> the total enthalpy, but of course we need to first calibrate this kind >> of enthalpy sensors. >> >> –Jouni >> > > > > You have again not specified the precise method you would use. > > It would appear you have
Re: [Vo]:Inexpensive steam/water calorimeter
On Sep 27, 2011, at 9:27 PM, Peter Gluck wrote: Dear Horace, The missing variable is cooling water flow- to be established by Rossi- water that carries the excess heat generated by the 52 (?) Fat Cats and is partially transformed in steam- F1. To achieve accuracy in delta T measuring the condensing water flow rate should be adjusted to the flow rate of the steam. If the flow is too high the delta T is small and even very small errors in measuring T translate into very large errors in delta T. If the device enthalpy varies rapidly then it is much easier to adjust the cooling water flow to a longer term moving average than to instantaneous measurements. The flow of mixing water- condensing the steam is say, 5-10 times greater than F1 see please the "formula" given in my paper. Like most people I don't generally go looking for a URL if it is not provided in a reference. What matters is not the mixer cooling water flow rate but its combined temperature and flow rate. The flow has to be matched to the steam thermal power, mass flow, and cooling water temperature in order to achieve a significant delta T. This problem does not exist when the steam is condensed into a very large thermal mass of water - provided the large mass is kept in a useful temperature range, and the thermal power from the secondary cooling circuit is matched to the device thermal power. If the thermal mass is large enough such matching can take place gradually and even manually, provided it is properly recorded. No peristaltic but other types of positive displacement pumps to be used, I said, "Unfortunately my two peristaltic pumps are too small for this power range." This does not imply that I would even consider trying to buy large peristaltic pumps. Perhaps we have a language barrier. Also, the flow rate for the cooling water should ideally be adjustable to the thermal power output of the device if that is variable and unpredictable. An adjustable flow rate pump, or a selection of pumps, would thus be useful for driving the secondary cooling circuit. e,g. gear pumps- for which the flow is not influenced by counterpressure. The flow rate of gear pumps is influenced by a pumping into a large pressure head, both due to rpm loss (slip) for AC induction motors under load, and due to rotor seal leakage under high pressure. In the case of the new Rossi device, it looked like perhaps the water flow was entirely blocked towards the end of the test. This would create as large a pump pressure head as required to terminate flow. The evidence for flow blockage was the high pressure the device was under at the end. This system measures the enthalpy in any moment, Including the start up period and possibly the heat after death. The mass flow measurement depends on measuring the mixer exit mass flow. This flow likely contains bubbles, is not well thermally mixed, and has fast dynamics requiring fast sampling times. Some degree of smoothing increases reliability of the numbers and reduces the required sampling rate. A large degree of smoothing provides a first principle check on the flow calorimetry numbers. Of course, in the case of Rossi's device any even low precision mass flow calorimetry is an improvement. In the case of my own work I would like some degree of consistency checking. A hybrid method provides this consistency check. The formula for efficiency is actually O/3I because electrical energy is at least 3 times more valuable or expensive than thermal energy That is not a formula for efficiency but relative value. Peter On Wed, Sep 28, 2011 at 7:38 AM, Horace Heffner wrote: On Sep 27, 2011, at 9:35 AM, Jouni Valkonen wrote: 2011/9/27 Peter Gluck : The simplest solution is to use a Steam Water mixing valve,in which the heated mixture coming out from the demo is mixed with a constant flow of cold water, you can know the enthalpy performance in any moment. Indeed, continuous experiments easiest way is to use enthalpy sensors, that gives as total enthalpy for any given moment. Even more simple is to measure the steam pressure inside E-Cat, because it gives directly the total enthalpy, but of course we need to first calibrate this kind of enthalpy sensors. –Jouni You have again not specified the precise method you would use. It would appear you have a case of missing variables. The principle missing variable is mass flow, m dot, which is best to isolate and measure directly. Best regards, Horace Heffner http://www.mtaonline.net/~hheffner/ -- Dr. Peter Gluck Cluj, Romania http://egooutpeters.blogspot.com Best regards, Horace Heffner http://www.mtaonline.net/~hheffner/