I just bought the same one for myself today! The "in" temp what the base unit is reading from the vent in the bottom (this is also where the humidity is being read from). The "out" temp is what the probe tip is at. If there is a difference in height of where the two readings are being made, this would explain the difference in your temps. I put the probe in a water wiggler so that the "out" temp approximates what the temp would be inside an egg. Good luck!
Thank you, that answers my question, where can I find a water wiggler? I notice you are from Mass and I am from NH so we kind of have the same stores around. Would anything else work beside that wiggler?
I like the water wiggler, simply because the water will better simulate the inside of an egg and will more accurately mimic the egg's ability to hold it's temperature (due to more similar physical properties). I borrowed my daughter's water wiggler, which she got at an iparty store. Other members have mentioned finding them in the cheap toys aisle at Walmart or the dollar store. I went to our local Walmart and Dollar Tree yesterday and did not find them. The dollar store said they usually carry them. It's kind of hit or miss. You could make your own by filling a zip baggie with water and smushing it into a paper cup or something. Place the probe inside whatever you decide to use and put it at the same height as your eggs (on top of turner if you are using one; on the wire bottom if you are not).