When using a probe thermometer, one should insert the stem of the thermometer into the thickest part of the food or the center if the food has even thickness. For liquids such as soups or stews, stir the liquid to evenly distribute heat before taking the measurement. Wait at least 15 seconds for the temperature reading to stabilize before recording it. Avoid letting the probe touch the bottom or sides of the container to ensure an accurate reading. Also, probe thermometers should be cleaned and sanitized before and after each use to avoid cross-contamination. Calibration of the thermometer is important and should be done regularly, especially before first use, monthly, and after any incidents like dropping it, using the ice bath method to ensure accuracy. Different types of probe thermometers exist, so it is advisable to follow the manufacturer's instructions on usage and calibration to achieve safe and accurate food temperature measurements.