Thanks for remembering this experiment from Simon Brink ! The effect is surprisingly large and my bet is that it only works well with 316 grade SS. If so - that would be good evidence for Mills' theory and the importance of the lowest energy catalyst. Nickel alone should not work as well.
As you suggest, eliminating color change should be attempted but for those who follow Holmlid, another wrinkle would be using a laser pointer Bill Antoni wrote On a related note, Simon Brink proposed a good while back an experiment with electrolytically H-loaded SS316 plates exposed to infrared light; he suggested that excess heat would be generated with high repeatability, using thermometry. http://subtleatomics.com/excess-heat I'm not entirely convinced by this approach as electrolysis could affect surface emissivity (the cathode can turn dark or black after prolonged electrolysis), but it could be a starting point under simpler experimental conditions. Cheers, BA
