Check out my demo and review of the Testo 557 digital manifold.
Check superheat and subcooling very easily and quickly. Built in pressure temperature chart for many refrigerants.
I dunno by grapes (c) copyright 2008 Licensed under a Creative Commons Attribution (3.0) license. http://dig.ccmixter.org/files/grapes/16626 Ft: J Lang, Morusque
Weather HipHop Instrumental Track by Xalpheric (c) copyright 2015 Licensed under a Creative Commons Attribution (3.0) license. http://dig.ccmixter.org/files/Xalpheric/49261