In most situations you are going to want the top heat source considerably hotter then the bottom for an even bake. The stone is transferring heat via conduction, it has a big advantage. In this situation that may not be the case. I could be wrong, but I think the dome here is more of an insulating refractory, in which case the hot air will be doing all the top cooking. If that is the case measuring the air temperature like originally asked about will probably be the better way to go.