Understanding Thermometers

To understand how a meat thermometer works, it's important to have a basic understanding of thermometers in general. "Thermo" means heat in Greek, while "meter" is to measure. A thermometer measures heat. With two important elements, the sensor and the reader, a thermometer can measure a physical change in temperature and convert that change into a value that is easily understood. There are many kinds of thermometers, including bulb thermometers, electronic thermometers and bimetallic thermometers. Meat thermometers are bimetallic thermometers.

What is a Meat Thermometer?

A meat thermometer is used to measure the internal temperature of cooking meats. From poultry and lamb to pork and beef, meat must reach a certain internal temperature in order to kill any pathogens that may be living inside. These pathogens can cause food borne illnesses if ingested. The meat thermometer is designed to display temperatures ranging from 140 degrees F to around 200 degrees F.

How Do You Use Meat Thermometers?

A standard meat thermometer has two parts: a display and a temperature rod. The rod is pushed into the meat by pushing on the dial. As the meat's internal temperature increases, the rod transfers the heat to the dial, which keeps track using a small dial. The display can be either digital or the old fashioned dial method. When the meat reaches the desired internal temperature, it can be safely eaten. The meat thermometer is simply pulled out of the meat, washed and stored until next time.

How Does a Meat Thermometer Work?

A meat thermometer takes advantage of the fact that different metals expand and contract at different temperatures. The rod of the meat thermometer contains two different metals that are bonded together. One expands at a lower temperature while the other must reach a higher temperature. The heat causes the strip of metal to bend or twist, depending on the temperature of the meat. The twisting metal triggers the dial and produces the readout on the display face of the meat thermometer. When the metal is no longer being heated, it expands and the dial "winds" down.