you wrote "People who understand these meters tell me it is not a joke at all. The meter with that probe is fine for that purpose. There would not be much point to making an RH meter probe is intended for a range of temperature up to 300°C that does not work with steam."
My guess (without digging up the probe manual which I've read some weeks ago) is the probe is capable of surviving up to 300 C, not that it correctly measures relative humidity up to 300 C. But this is a moot point because any test that Rossi does is going to have 100% Relative humidity at the end of the hose because the steam is partially condensing already when it leaves the hose. see here http://en.wikipedia.org/wiki/Relative_humidity How can a Relative Humidity probe measure the ratio of the mass of vapor to the mass of liquid droplets when it is pegged at 100%? If Noone Noone comes back with some capacitance thing I'm going to ask him to do some more research because I can't explain science to him.
