evaporograph

evaporograph

(ɪˈvæpərəˌɡrɑːf)
n
(Environmental Science) an instrument which measures and records the rate of evaporation of water into the atmosphere
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014