I looked for this yesterday and couldn't find it, it's a good read.
I don't know how accurate this pdf is since it says the spheres are in a silver bead bath, not water but it then says in the same pdf that the beads were aluminum???
The control sphere only had sand in it according to the same article that I have excerpted below.
The setup is pretty simple but if you wanted to deceive someone, it could be done, but why? Cravens' has a PhD so why would he throw all that away to fake something? Rossi's so called PhD was from a diploma mill so he has nothing to lose and has a criminal history. Then again, Randall Mills from Black Light Power has a chemical engineering degree and an MD from Harvard and has raked in over $60 million dollars which is a pretty good incentive but I think Mills believes he has something, why try to write a TOE if he doesn't so what would Cravens' reason for fraud be?
So what is in that warm golden ball? It contains an activated carbon that holds metal alloy within its pores, some magnetic powder, some hydrogen storage material and some deuterium gas. It is thought that the heat is coming from the fusion of deuterium nuclei to go to helium. However, there are as many ideas of the exact reaction as there are theorists. What is clear is the mixture produces heat because the sample sphere in it is warmer than the control sphere containing a little sand. The two spheres are in a highly conductive bath of aluminum beads in a constant temperature bath designed to be uniform and to hold the temperature constant.
In this article, in the first sentence, there's a link to the pdf under, "full length article".