Cons: Must be checked for accuracy using proven means
The basic incubator thermometer is recognized by its glass tube w/red color alcohol, black or blue numbers, and a clear plastic sheet which is used to rest the thermometer on top of your incubating eggs.
Generally, they are a good purchase. Where money is a consideration, use this type. Buy more than one, so that you can have them in several locations in your incubator. Always test your thermometer.
I always test my thermometers against a proven thermometer in my incubator (that I know to be reliable based on hatches onthe expected hatch dates). However, if the numbers go down to 32, you may put it into ice water. After 5 minutes it should read 32. Adjust your expected hatch temp accordingly. If it says 34, it is two degrees hot, if it says 30, it is two degrees cool. Alternately, test it in warm/hot water against a human medical thermometer. They should read the same. Be dubious of any thermometer more than 3 degrees off. (If put under a healthy persons arm, it should read 97.9-98* (one degree less than oral).
