EE: Yes, you're on the right track... see my posting at 6/21 at 9:04pm. http://www.mail-archive.com/[email protected]/msg48242.html I would bet that Galantini is making an indirect measurement of the liquid water content as explained in my posting.
-Mark _____ From: aieie brazof [mailto:[email protected]] Sent: Wednesday, June 22, 2011 4:13 AM To: [email protected] Subject: Re: [Vo]:relative humidity Dear all, this is my guess. I hope it's correct, but thank you very much in advance for correction if necessary. -The stated probe only measures relative umidity. If liquid phase is present, then R.U. is always 100%. what follows only applies for vapour-air mixture - knowing the temperature and R.U., data logger can calculate the vapour fraction of the mixture, also known as X=gr(vapour)/kg(dryair). It's just a calculation and no measurement is required. If no dry air is present, such calculation is sensless. -Back to saturated steam: in presence of liquid phase this kind of probe only give us 100% UR. (if not broken down because of too much vapour density and no air!). In order to measure the liquid fraction of a saturated steam, (Mliquid/Mliquid+gas) this probe is completely useless. An "academic" way to carry out the measurement of the liquid fraction of a saturated steam, is based on superheating by isohentalping expansion through a valve. Perhaps there are transducer for this purpose. For sure not the one we are talkin 'bout. Psychrometry is where we have about 30g of water as gas and 1kg of dry air. This is the field of such probes. Saturated steam is not the same. I'm very confused. Sorry for my poor english. Best Regards. EE
