The discussion related to Galantini using the wrong instrument to measure steam quality in Rossi's experiment seems to be slowing down.
But here are details on how a relative humidity sensor works (as others have also mentioned). It uses an extremely thin plastic (one manufacturer uses a one micron thick polymer) between two metal plates which creates a capacitor. I assume there are holes in the face of the metal plates so that the water can migrate into and out of the plastic faster. This is because the water couldn't migrate through the bulk fast enough if it just went through the microns thick plastic exposed at the edge. The capacitance changes as the water is absorbed. The manufacturer correlates capacitance with humidity and temperature in air at 1 atmosphere (if they wanted to go to higher pressures then then would have to add a device to measure pressure and add that as a correlation - but few customers would really need the capability for higher pressures) here are details on the construction of Relative Humidity meters: http://www.stevenswater.com/catalog/stevensProduct.aspx?SKU='51122' http://sensing.honeywell.com/index.cfm/ci_id/140576/la_id/1/document/1/re_id/0 http://www.ddc-online.org/Input-Output-Tutorial/Humidity.html http://www.jifbrunei.com/files/083DHumidity.pdf The amount of water absorbed by the plastic depends on how many water molecules hit the plastic per unit time which is directly related to the partial pressure of the water. The sum of the pressure due to the water vapor molecules plus the pressure due to the air molecules equals 14.7 psia. The plastic absorbs more water when the partial pressure of the water is 3 psi than if it is 1 psi, for example. So, for example the vapor pressure of water at 90 C is 10.1 psia and therefore the air has a partial pressure of 4.6 psia (because 14.7 - 10.1 = 4.6). The plastic probably does not even know the air is there - i.e. the capacitance may not change much if the air was taken away while keeping the water at 10.1 psia. At 100 C (boiling), the vapor pressure of water is 14.7 psia and the capacitance is some value. Here is the key point: At 100 C, how much water would the plastic absorb if the steam was 100% quality (i.e. dry) compared to 0% quality (i.e. wet or also known as fog). The answer is the capacitance would be virtually the *same*. So therefore, a Relative Humidity meter can not be used in any way to determine the quality (also known as dryness) of the steam and the supposed expert Galantini made a huge mistake. here are some graphs of water vapor pressure for reference: http://en.wikipedia.org/wiki/File:Water_vapor_pressure_graph.jpg http://www.engineeringtoolbox.com/water-vapor-saturation-pressure-air-d_689.html Here are the specs on one of the probes Rossi used: HP474AC Relative Humidity Probe specifications: 5% to 98% RH >>> -40C to 150 C +/- 2.5% (5%...95%RH) +/-3.5%(95%...99%RH) Temp +/-0.3C Note that it works at 150 C. The probe probably senses a capacitance change as the temperature is increased from 100 C to 150 C but the water pressure would also have to increase so that more water was driven into the plastic of the capacitor. The capacitance changes as a function of water vapor pressure. It does not change as a function of steam quality. here is the Testo 650 relative humidity instrument that also Rossi used: http://www.ipi-online.com.au/test-and-measurement/data-loggers/testo/176-h2-data-logger Galantini wrote the following: "...The instrument used during the tests performed in the presence of Swedish teachers was as follows: 176 Text Code 0572 H2 1766 ." from the Testo data sheet: "...When normal humidity logers are too sensitive, the testo 176 H2 comes into its own. The robust metal housing resists mechanical influences and adverse ambient conditions. It has two connections for external humidity probes which can be positioned in the room according to the individual requirements." 4-channel temeprature and humidity data logger in metal housing with external sensor connections (NTC/ capacitive humidity sensor) * Large memory for 2 million measurement values - robust metal housng (without display) * up to 8 years battery life * Standard battery (AA) replaceable by user * Scope of delivery: Data logger testo 176 H2 incl. wallholder, lock, batteries, calibration certificate and instruction manual Measuring range -20 to +70°C -40 to +70°Ctd 0 to 100%RH Accuracy ± 0.2°C (-20 to +70°C) Resolution 0.1 °C 0.1 %RH / g/m³ Conclusion: Galantini, a chemistry professor (as far as I know) screwed up royally. Keep in mind, Rossi keeps insisting on measuring energy using water vapor that he quickly gets rid of down a drain. Is there a reason he gets rid of the evidence? Is there a reason that Galantini used the wrong sensor for steam quality? -------------------------------------------------------------------------------- Note, I'm a mechanical engineer with 21 years of experience and a masters degree in mechanical engineering. At one job, I helped a company design a pressure sensor that was capacitor based. You can see some of my previous cold fusion work over the past 20 years here: www.waterarc.com And here is my website that gives a beginners guide to Blacklight Power's Randell Mills's theory. www.zhydrogen.com Though I am not affiliated with Blacklight Power in any way (but I'm trying).
