Owing to high resistance to corrosion they are quite stable for a long time even under the influence of high temperature or within hostile environments. In a thermocouple, two distinct metal wires are joined at one end called the hot junction, where the temperature is to be measured and the wires at the other end are known as the cold junction. Since Pt or Pt and Rhodium thermocouple alloys are precious metals their market price is very high and fluctuates daily following the precious metals market. Thermocouple refers to a junction or coupling between two different metals which produces a voltage related to the temperature difference most of which are regularly used in various thermocouple applications. Extension wires can be made of the same metals as China ZXEV05-20A Automotive Relays Suppliers that of a higher grade thermocouple but that can be prohibitively expensive. The EMF voltage of the cold junction is measured and hence the temperature at the hot junction can be determined. As well as its practical advantage of being much stronger over long distances, an extension wire is less expensive than the price of the standard platinum thermocouple wires. Thermocouples find their main application as a temperature sensors for measurement and control. Platinum Group metals including Iridium, Rhodium and Platinum are all extensively used for manufacturing thermocouples. The most common diameter of these wires used is 0. Platinum thermocouples have the extension wire made up of an alloy using Copper that has the same EMF as the thermocouple, but can operate at lower temperatures. Platinum wire may be more efficient to use as an extension wire but it can be quite expensive to use this high priced metal wire as extension wire over long distances. When high temperature is applied to the wires, a voltage (EMF) is generated at the cold junction that can be measured. To understand Platinum thermocouple wire, it is first necessary to understand the term thermocouple. Whereas connections to the extension wires do not generate a voltage as they are made up of metals with the same resistance as the thermocouple wire. The solution to this can be to use narrower thermocouple wire at the measuring junction, but to use stronger thicker thermocouple extension wire made from a Copper alloy that can operate at lower temperatures to cover any longer distances. The mass and cost of the thermocouple can be minimized by using wires of smaller diameters, but wires with smaller diameters are more prone to strain, annealing and potential contamination.. Thermocouples play an important role in a number of industrial fields, since their application allows highly accurate temperature measurements to be achieved. Extension wires are used to connect to a measuring instrument which may lie some distance away without using any additional junctions or joins between dissimilar materials which may result in unwanted voltages. Also even in extreme conditions the precision and reproducibility of results are not affected.scrap-platinum.020' that is equal to 24 gauge, but there are wires of many other different diameters too. Very high temperature conditions do not allow the use of wires other than this type of precious metal wire. Thermocouples are supplied fitted with standard metals as connectors including Platinum group metals, and these can also measure a wide range of temperature. There are many types of Platinum wire thermocouple materials like Type S, Type R, Type B, or Platinel precious metal alloys. These are also used to convert heat into electrical power. Thermocouple wires of Pt and Pt-Rh are used whenever there are aggressive conditions in service or high measuring temperatures which can be upto 1600 - 1800 degrees Celsius. To maintain high initial purity up to the final diameter on the delivery spool, special melting procedures and a highly specialized production route are employed when manufacturing thermocouple wire.
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