Instant-read thermometers are not designed to stay in the food during cooking. If you are using an instant-read thermometer, pull the meat or poultry out of the oven far enough to insert the stem about 2 inches into the thickest part of the food but not touching bone. The temperatures should register in about 15 seconds. Before using a food thermometer, read the manufacturer's instructions. The instructions should tell how far the thermometer must be inserted in a food to give an accurate reading.
Most thermometers also come with instructions on how to recalibrate the thermometer.
Most digital thermometers will read the temperature in a small area of the tip. Dial types must penetrate 2 to 3 inches into the food. The reading will only be helpful, however, if the thermometer is placed in the proper location in the product. If inserted incorrectly, or if the thermometer is placed in the wrong area, the reading will not accurately reflect the internal temperature of the product. In general, the thermometer should be placed in the thickest part of the food away from bone, fat or gristle.