Kapton is a leading material of choice for insulating electrical wires in temperature-critical applications. It can be incorporated into conventional wiring designs, where single or multi-strand conductors are encased in a protective insulating sheath.
In this case, the insulator is a patented polyimide, used in aviation and space exploration, offering excellent thermodynamic stability and superior dielectric performance in vacuum conditions.
Allectra develops Kapton-insulated wires in a broad array of configurations and formats. These include traditional types for standard signal transmission, as well as coaxial cables and flexible ribbon harnesses for low-loss signal transmission in high-vacuum and ultra-high vacuum (HV/UHV).
Among their various precision Kapton-insulated wire products, Allectra also offers a selection of Kapton thermocouples for temperature-critical vacuum processes.
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What are Thermocouples?
A thermocouple is a temperature sensor that consists of a cable made of two different metallic conductors fused at one end to create a junction, which is exposed to the sensing environment. Readings from inside the chamber are transmitted to an external indicator through a hermetically sealed feedthrough, allowing for real-time continuous monitoring of in-vacuum temperatures.
Thermocouples do not read temperature directly but instead enable advanced software to calculate temperatures as a function of charge separation or electromotive force (EMF).
This process is dependent on material combinations. Type K thermocouples consist of Chromel (90 % nickel and 10 % chromium alloy) and Alumel (95 % nickel, 2 % aluminum, 2 % manganese, and 1 % silicon alloy) wires are among the most common thermocouple wire pairs.
Type K and Type N Kapton Thermocouples
The alumel-chromel (type K) pairing is commonly used due to its accuracy, reliability across an extensive temperature range, and cost-effectiveness. Type K thermocouples are utilized in various demanding working environments, enabling temperature measurements from -200 °C up to +1250 °C.
Type K thermocouples are compatible with a range of feedthroughs and measuring instruments. With excellent performance across a broad temperature range, they are optimal for temperature sensing in fields such as alternative energy research and advanced surface science.
Type N thermocouple wires provide high stability over time, with temperature measurements ranging from -250 °C to a maximum of 1300 °C.
Allectra supplies Kapton-insulated Type K & N thermocouples for temperature-critical vacuum processing. It is important to note that Kapton withstands temperatures up to +300 °C. Allectra now offers new 301-Type K & N Kapton-insulated thermocouple wires that are UHV compatible and radiation resistant.
This information has been sourced, reviewed and adapted from materials provided by Allectra Limited.
For more information on this source, please visit Allectra Limited.