Reflector

And on the 3rd week of school, I learnt something new today! There’s actually DRY STEAM!

Everyone was like “huh” when our indian lecturer talked about dry steam. Like what did he say? Dry steam? Sure or not? Isn’t steam water vapour? Should I believe him or not? Sounds so dodgy… so checked it up on the internet and here’s what it says:
Yes, you can have “dry” steam. A measure of the “wetness” of steam is
called quality. Quality varies from 0 to 1, with a quality of 0 being a
saturated liquid and 1 being a saturated vapor. When steam has a quality of
1, it is considered “dry” steam. If the quality falls between 0 and 1, it
is considered “wet” steam.

And

Look, if one takes the expression “dry steam” literally
it is impossible because “steam” means  “water vapour”
so dry steam would be inconsistent.
But…there are nowadays industrial equipments that
use that expression meaning something else.
So “dry steam” describes a system that produces
a high temperature with “low moisture vapor”. This
vapor contains only 5-6% water and is much less
dense than the air we breathe..
And thanks for asking NEWTON!

from http://www.newton.dep.anl.gov/askasci/gen99/gen99656.htm