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Type J thermocouple like any other thermocouple comprises of two conductors of different materials. The dissimilar conductors remain in contact and produce a voltage when they are heated. The scale of the voltage produced is dependent on temperature difference between other circuit parts and the junction. Besides being used to turn a gradient in temperature into electricity, they are also used to measure and control temperature.
The functioning of thermocouples was initially discovered in 1821 by a German scientist. It was noticed that a junction of metals of dissimilar type will produce an electric potential when exposed to a temperature difference. This theory is known as thermoelectric or Seebeck effect. Thermocouples that are designed for practical use are constructed from standard alloys, which have a repeatable and/or predictable relationship between temperature and voltage.
Different temperature ranges could be measured by use of different alloys. When picking a thermocouple, there are some factors to have in mind. One of them is ability to resist corrosion. In circumstances where the position of measurement is a distance away from the measuring device, the space between may be covered using extension cables. The wires must be made of materials that are less costly than the sensor metal.
Type J thermocouples are standardized against some reference value of zero degrees. They are made of an iron and a copper-nickel alloy wire. The iron acts as the positive lead and is normally colored white. The copper-nickel alloy is the negative lead and is always colored red in most cases. It is the second most popular and most used thermocouple after type K.
This sensor has a sensitivity of over 50 microvolts for every degree centigrade of temperature. That sensitivity works at a temperature range of between -210 to 1200 degrees Celsius. The Curie point of iron in the positive lead which is placed at 770 degrees Celsius limits the range of the device between -40 to 750 degrees Celsius. At the Curie point, iron goes through a molecular change from which it cannot recover.
Type J thermocouple is among the most cheap sensors and works best in certain environments. For instance, they are not supposed to be exposed to high temperatures in oxidizing environment. High temperatures should go with a reduction surrounding. It is a good device for use on general purpose applications that do not involve water of moisture conditions. Heavier gage size devices should be used for applications that involve temperatures that reach the higher limits of the equipment.
The service life of the product depends on the size of the wires. The rate of oxidation in devices with heavier wires is slow hence they last longer than those with fine wires. Oxidation also occurs at a higher rate at temperatures beyond 540 degrees Celsius. If the precautions are followed well, it can be used for measuring temperature in diesel engines, gas turbine exhausts, and kilns.
Type J thermocouple may be acquired from virtually any shop that stocks electrical appliances anywhere worldwide. They are replaceable and cheap. This implies that those that become defective can be replaced with fresh ones. This ensures that operations are not interrupted.
The functioning of thermocouples was initially discovered in 1821 by a German scientist. It was noticed that a junction of metals of dissimilar type will produce an electric potential when exposed to a temperature difference. This theory is known as thermoelectric or Seebeck effect. Thermocouples that are designed for practical use are constructed from standard alloys, which have a repeatable and/or predictable relationship between temperature and voltage.
Different temperature ranges could be measured by use of different alloys. When picking a thermocouple, there are some factors to have in mind. One of them is ability to resist corrosion. In circumstances where the position of measurement is a distance away from the measuring device, the space between may be covered using extension cables. The wires must be made of materials that are less costly than the sensor metal.
Type J thermocouples are standardized against some reference value of zero degrees. They are made of an iron and a copper-nickel alloy wire. The iron acts as the positive lead and is normally colored white. The copper-nickel alloy is the negative lead and is always colored red in most cases. It is the second most popular and most used thermocouple after type K.
This sensor has a sensitivity of over 50 microvolts for every degree centigrade of temperature. That sensitivity works at a temperature range of between -210 to 1200 degrees Celsius. The Curie point of iron in the positive lead which is placed at 770 degrees Celsius limits the range of the device between -40 to 750 degrees Celsius. At the Curie point, iron goes through a molecular change from which it cannot recover.
Type J thermocouple is among the most cheap sensors and works best in certain environments. For instance, they are not supposed to be exposed to high temperatures in oxidizing environment. High temperatures should go with a reduction surrounding. It is a good device for use on general purpose applications that do not involve water of moisture conditions. Heavier gage size devices should be used for applications that involve temperatures that reach the higher limits of the equipment.
The service life of the product depends on the size of the wires. The rate of oxidation in devices with heavier wires is slow hence they last longer than those with fine wires. Oxidation also occurs at a higher rate at temperatures beyond 540 degrees Celsius. If the precautions are followed well, it can be used for measuring temperature in diesel engines, gas turbine exhausts, and kilns.
Type J thermocouple may be acquired from virtually any shop that stocks electrical appliances anywhere worldwide. They are replaceable and cheap. This implies that those that become defective can be replaced with fresh ones. This ensures that operations are not interrupted.
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