A thermocouple is a device, which senses temperature by using two different metals joined at one end. This article will tell you more about the functioning, types, and uses of this device.
Thermocouples are largely used in the fields of science and electronics as a temperature sensor, which are quite easy to handle and use. The functioning is based on the Seebeck effect, common in case of electrical conductors, that experiences a temperature gradient along their length. These sensors are simple, rugged, do not need batteries, and have the ability to measure very wide temperature ranges. They consist of two different metals, joined together at one end. Whenever the junction of the two metals is heated or cooled, a voltage can be obtained, that is proportional and can be correlated to the temperature, that was given when the sensor was heated. Thermocouple alloys are usually available as a wire. They are quite cheap, but their main drawback is their accuracy.
Why do you need to measure temperature? Think of all the ways temperature measurement is important in your life. If you know the temperature outside, you know how to dress to go out. If you know the temperature inside your oven, you know if it is hot enough to cook a pizza. You can probably think of many more examples. Different types of thermometers can be used to measure temperatures. Since solids, liquids, and gases usually expand when heated and contract when cooled, almost any substance could be used in a thermometer. The choice usually depends on the way the thermometer will be used…
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Quiz on Vocabulary associated with Temperature and Thermometric Properties
Wonderful animation on how to calibrate an alcohol-in-glass or mercury-in-glass thermometer.
1. How could you make this experiment more accurate?
2. How could you use this experiment to calibrate other types of thermometers?