I bought a thermometer that has a nut for calibration and I used the ice water method. No problem. Then my incubator arrived and the calibrated thermometer said it was way off. I was surprised that a new Brinsea was so far off, but I figured I'd try my cheap digital kitchen thermometer. Since I was killing time waiting for dough to rise, I went with the boiling method and the thermometer was right on. But it disagreed with the calibrated dial thermometer by about 10 degrees F! So I took both back to the kitchen and got the water boiling again, AND set up an ice water bath. The digital kitchen thermometer was spot-on in both tests. The dial one is incapable of being correct - its scale is off. If calibrated to boiling at 212F, it "freezes" at around 40-42F. If calibrated to freeze at 32F, it "boils" at about 200F. This is my first time incubating and I can easily imagine this having become a nightmare of non-hatching mysteries. I'm so glad I had time to kill in the kitchen that day BEFORE I picked up my eggs! (And I was right to be surprised that the Brinsea was so far off - it's not quite a whole degree F off.)
