Correct Incubator Temp - top or bottom of the egg?

[Star Valley]

I just bought a little giant incubator and put 18 Black Star eggs in yesterday. The instructions say to have the temp at 99.5 degrees at the top of the egg.

So I tested two thermometers before I started and they registered the same. I placed one on top of the eggs and have 100 degrees. The one laying on the floor says 93 degrees.

Should I be seeing that much difference? The incubator is heated by a heating element (much like a broiler oven from the top)

Thanks
Mark in Star Valley, Wyoming

 

[johnnalei]

I'm incubating my first hatch right now. I have a Hova-bator, still air. I think that must be pretty normal because I'm seeing something similar. I have three different thermometers in mine (since it's my first time and I don't trust any one thermometer yet). When I was setting it up and letting the temp stabalize, I had all three on the floor and they were very similar, so I assume they are all equally accurate. Now I have eggs in and one digital thermometer on the floor, one digital on top the eggs, and the one that came w/the incubator on top the eggs. The two on top the eggs read around 100 degrees and the one on the floor reads around 96 most the time. So guess it's normal, but I'd be interested to hear what people say!

 

[Star Valley]

Thanks johnnalei. That makes me feel better that this is probably normal. Hopefully we'll get some other input from those with some experience with this.

Mark in Star Valley, Wyoming

 

[Intheswamp]

Quote:
Well, I'm not experienced but I've been reading in one of Jull's books written back in 1938 and it stated that (as best I remember, I don't have the book in front of me) there is up to a 13-degree difference between the top and bottom of an egg that is being incubated by a hen. So 7 degrees doesn't sound abnormal according to his findings. Toward the end of the incubation period the temperature stabilizes much more.

Ed