Whenever you purchased a new thermometer and about to use it for the first time, you need to calibrate it. Thermometers will also need to be calibrated whenever they are dropped or when going from one temperature extreme to another. Thermometers are a critical measuring equipments for temperature to ensure good hatch rates. There are two methods that you could use to calibrate thermometers - Ice Point Method - Fill a container with crushed ice and water. Ensure that the container have enough crushed ice to provide an environment of 32 degrees F, so you may need to add more ice into the container during the process. It will takes about 4 to 5 minutes for the mixture of water to stabilized. Then insert the thermometer which needs to be calibrated into the appropriate immersion depth. Hold the thermometer away from the bottom and sides of the container to avoid error. If your thermometer is not accurate at 32 degrees F, adjust the thermometer accordingly. Boiling Point Method - Fill a container with distilled water and heat it up. After the temperature in the water has reached the boiling point, insert the thermometer . Be sure to leave at least a two inch gap between the thermometer sensing element and the bottom and sides of the container to avoid error. If your thermometer is not accurate at 212 degrees F, adjust the thermometer accordingly.