I recently got a used lab incubator, with a heating element on the bottom of the unit, and I've been trying to make this suitable for hatching eggs. This is what it looks like:
I thought I had the temperature holding steady, so I put my eggs in. The next day, I realized that due to a massive temperature gradient in the incubator, I have probably cooked my poor eggs. I'm leaving them in there for now, to help me try and get the conditions right for the next eggs that I put in.
In these pictures, I have two thermometers in the incubator. You can see one of them on the top shelf. There is another one (the Brinsea Spot Check thermometer) with the probe hanging down right over the eggs in the second picture. There is about a ten degree differential between what the thermometer is reading on the top shelf, and what the Brinsea spot check probe says. If I then move a thermometer to the very bottom shelf, and leave the Brinsea one where it is, the one on the bottom shelf reads 110 and the Brinsea one right over the eggs reads 90. I also have an infrared thermometer that I can use to check egg shell temps. Doing that, the egg shells read between 91 and 100 degrees.
How can I fix the crazy temperature differential in this incubator? I do have a computer fan blowing in there. It's hard to see in the picture, but it's blowing from the left side of the incubator, across the heating element, to the right side of the incubator. We've also tried resting the fan on the bottom shelf and blowing straight up through the eggs, which also didn't fix the problem.