An electric thermometer uses electricity to measure temperature. An electric resistor known as a thermoresistor is the key to the electric thermometer. This sensor's resistance is changed by a fluctuation in temperature. A small computer calculates the change and converts the readout to temperature. This technology allows much faster temperature taking at the doctor's office as well as on a building's outside temperature reading display.

Unlike mercury-type thermometers, the electric thermometer can display the temperature in a matter of seconds. The reading from the electric thermometer is considered much more accurate since the typical thermometer is difficult to leave under the tongue for the entire length of reading and testing. By opening the mouth to breathe or even to simply adjust the way the thermometer is sitting under the tongue, the reading can be flawed. By speeding up the process, the reading from the electric variety is more accurate.

The many uses of the electric thermometer are not limited to the doctor's office. This thermometer can be used to activate other electronic devices at a predetermined temperature. Furnace controls in the common home as well as cooling devices within the corner grocery store can both be controlled by an electric thermometer. When the thermometer detects the proper temperature, it sends a signal to another on or off switch that either engages or disengages, turning the cooling controls on or off. The benefit is the automatic and very accurate control of the system as compared to timers or dependency on human interaction.

In a manufacturing setting, the thermometer makes it possible to control heating temperatures of products as well as cooling fluid temperatures to an exact degree. In some critical manufacturing process such as heat treating metal, a fluctuation of the most minimal amount can mean the difference in a quality item or scrap. The same goes with cooling fluids. By maintaining the constant temperature of a cooling fluid, a machine can have a much longer life span and deliver high-quality work with a minimum of breakdown.

An everyday use that affects many people in a much more personal manner can be found in the kitchen. Advancements in the electric thermometer have made it possible for a chef to cook a roast to perfection each and every time. By taking a quick internal temperature reading from an electronic thermometer, the chef can determine the proper cooking time and temperature of the meat. The fast read allows the chef to remove the meat from the fire in the proper time to avoid over-cooking and also ensures that an undercooked product never leaves the kitchen.