There are many different types of food thermometers:
Dial Oven-Safe (Bimetal) can be used in roasts, casseroles, and soups and can remain in food while it's cooking.
Digital Instant-Read (Thermistor) can measure temperature in thin & thick foods but is not designed to remain in food while it's cooking.
Dial Instant-Read (Bimetal) can be used in roasts, casseroles, and soups. The temperature is averaged along the surface of the probe, from tip to 2-3" up the stem. This one is not designed to remain in food while it is cooking.
Thermocouple, also digital,good for measuring temperatures of thick and thin foods, but not designed to remain in food while it's cooking. This one is more costly and may be difficult for consumers to find in stores
Oven Probe with Cord can be used in most foods and also be used outside the oven, it is designed to remain in the food while it is cooking in the oven or in a covered pot. The base unit sits on the stovetop or counter.
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