I am not sure evaporation can be predicted as surely as you suggest, plus it is not the only way water can leave the cell and thus mask a possible recombination. Horace rightfully mentioned electrolyte droplet entrainment, I have witnessed the reality of this phenomenon myself (visible traces of salt remained after letting dry a spoon exposed to the outgoing vapor). Also, recombined water can simply leave the cell in vapor form, leaving no other trace of the recombination than heat.
For all these reasons, I think open cell heat measurements cannot be conclusive. Closed cell rules in this domain, as you know of course. Michel 2009/1/4 Jed Rothwell <jedrothw...@gmail.com>: > Michel Jullian wrote: > >> Evaporation could conceivably have been 5.5cc instead of the 0.5cc >> assumed by Melvin (7.7cc - 7.2cc) . . . > > No, it could not. The physics of evaporation are well understood and can be > modeled and tested in detail. Evaporation is governed by temperature, and > the electrolyte temperature is measured precisely. Experiments producing no > excess heat sometimes have more overall power output (from higher powered > electrolysis) than the experiments that produced excess heat, but the water > level change was exactly as predicted by conventional electrolysis. > > Conventional evaporation and electrolysis are well understood. They do not > suddenly and inexplicably produce 5 cc changes instead of 0.5 cc. Open cell > electrochemistry has been done for well over 100 year. Also, Miles uses > other reliable methods to confirm the flow of gas is as expected, for > example capturing the gas in an inverted, water filled test tube. > > - Jed > >