Wonder if any one can help..I set up a polybox incubator, left the pulse stat free hanging in the polybox, put a digital thermometer probe in the tub,,eggs have been incubating for over 4 weeks, all eggs are alive & growing..however I tested my eggs surface temps as the eggs felt cool..thermometer reads at 88.5 in the tub but the surface temps of the eggs are 84f..have placed the stat probe inside the egg tub & put the temp probe into the poly box..any ideas