I calibrate my hygrometers every year to keep my incubator humidity accurate. You should also be checking your thermometers for accuracy before using them. If it does not have one built in, I add 2 inside. If my incubator has a built in thermometer I add another one inside. Use 2 different thermometers/hygrometers to check it. To test an incubator, turn it on and leave it on for at least 48 hours. Now obviously if you're hatching in succession you don't need to stop and test between hatches, but if the incubator has been off for any length of time you need to test it before setting eggs. You want to make sure your incubator is holding steady before you add eggs to it. Settings can get bumped, the incubator shell could have developed a crack during storage or the heating element could have burned out. Whether it's a brand new incubator or the same one that you use every year, it needs tested before each hatch to make sure the temperature and humidity are correct.

Not testing your incubator: Every incubator should be tested before every hatch. These are the ones that end badly every single time. Another year with those and I moved on to 1 then 2 cabinet incubators and I've learned quite a bit in all those years of hatching! Here are the 4 biggest mistakes I've made. I hatched chicks, ducks, quail and guineas using those for a few years before moving on to small Brinsea incubators. Within a few months I needed more space so I moved up to 2 Styrofoam incubators with and without turners. I started by making my own incubator, which is easier than it sounds. I've been hatching my own chickens since 2009.

Diy egg incubator turner