I have 3 Coopers that measure temp and humidity. they are accurate and all 3 read the same thing. Here is a link for a new one but you can get them used in like new condition for a fraction of this price.
naw no probe but the whole thing sits in the lg incubator and doesnt take up space. got it to check humidity and also wanted to double check the wafer. so after getting it they both so the same temp so guessing they are both right. what ya need a probe for? you have a homemade with no windows?
No, I read about this trick of using one of those kids toys with the liquid inside that you squeeze, shaped like a tube, has little floaties in it? You can put the probe inside and it will help you gauge what temp the eggs are (vs. the air). You can then use it to calibrate the incubator. Sounds like a good idea. BYC'ers, please feel free to debunk this if it's not.
I haven't hatched anything yet...but I'm thinking I better make sure I can get everything right before starting...