Ways Andrea Rossi will know if he is working with the same phenomena that has been observed by other researchers
IMPO Andrea Rossi will have seen many of the effects that go along with the Active Agent and its spin off (also an Active Agent) SR - at least in the macro form. He has not shared microscopic images of studies of his failed reactors, but if the old 'failures' still exist and he has a spare $60, he should get a NURUGO lens and have some fun analysing them or throw them on a laser or scanning electron microscope.
This is not an exhaustive list, but some of these effects include
'excess cooling' [think of the implications]
destruction of reactor structures below normal temperatures
Anomalous glowing without real heat corresponding to the usual 'colour temperature' - IMPO will fool bolometers
misreading of TCs
liquification / disruption of metals, particularly aluminium. The higher the melting point and the lower the conductivity / Electron Affinity, the faster the transition from stable lattice to, well, not how it used to be!
accelerated 'corrosion' such as oxidation with high levels of sulphur production at surfaces in contact with air, particularly if metal is Iron-rich
failure/disappearance of refractory ceramics - particularly alumina
Emission of low energy beta / photons
Emission of broad spectrum photons similar to bremsstrahlung radiation but not necessarily with characteristic x-rays
Intense reverse voltage spikes and/or low voltage reverse current
problems with overheating in inductive parts of control electronics, even those that apparently are isolated
failure of equipment at distance, even those that are not connected
fatigue of operators around reactors that are not properly screened
self-sustaining spheroid or toroidal structures that may leave apparatus
plasmatic like effects at surfaces of materials, particularly metals, particularly aluminium, that look like fire, but are not in fact fire.
impulses that could be used as propulsion source
other directional affects dependent on EM configuration of the equipment
increased appearance of above effects when 'control' power is switched off
element synthesis and transmutation
thing appearing where they were not before