Oven thermometer

Home ovens often run hotter or cooler than the dial says, and they cycle above and below the set point as the heating element turns on and off. An oven thermometer, either a dial type or a digital probe, is placed on the middle rack so you can read the true temperature and adjust the setting.

For baking, this matters a great deal. A cake, cookie or soufflé baked in an oven that is off by even a modest amount can sink, spread or brown too quickly. Bakers check it after a full preheat, and moving it around the oven also reveals hot spots that call for rotating pans.