Monday, February 25, 2019

Thermocouple Wire Insulation Materials

Thermocouple Wire Insulation

Insulated thermocouple wire is single pair wire that can be made into a thermocouple. Thermocouple wire is available with many types of electrical insulation. The choice of the proper insulation material is based on cost, temperature rating, chemical & UV resistance and wear resistance. Below is a run-down of the most common thermocouple wire insulation materials.

  • Suggested operating range: -85°F to 250°F (-65°C to 121°C)
  • Nylon provides high tensile, impact and flexural resistance.  It has excellent resistance to abrasion and is unaffected by most alkalis, oil, grease, dilute mineral acids and most organic acids.  It is inert to most organic solvents including hydraulic fluid and aviation oil. The individual conductors and outer jacket are extruded.
Fluorinated Ethylene Propylene (FEP) 
  • Suggested operating range: -90°F to 400°F (-67°C to 204°C)
  • FEP retains useful strength and flexibility over broad ranges of environmental temperature or thermal aging. FEP is flame retardant and non-propagating in fire conditions. It is moisture and chemical resistant and accepted for use around food and pharmaceuticals. The individual conductors and outer jacket are extruded.
Perfluoroalkoxy (PFA) 
  • Suggested operating range: -328°F to 500°F (-200°C to 260°C)
  • Flame retardant PFA provides flexibility and toughness with stress crack resistance, resistance to weather, non-aging characteristics and a low coefficient of friction.  PFA also provides outstanding electrical characteristics, as well as resistance to virtually all chemicals.  The individual conductors and outer jacket are extruded.
Tetrafluoroethylene (TFE) 
  • Suggested operating range: -328°F to 500°F (-200°C to 260°C)
  • TFE is flame retardant (passes IEEE 383 & VW-1 flame tests) and has excellent solvent and abrasion resistance.  TFE is unaffected by long term exposure to virtually all chemicals and solder iron temperatures. The individual conductors and outer jacket are insulated with TFE Tape.
Polymide Tape (Kapton) 
  • Suggested operating range: -400°F to 600°F (-240°C to 315°C)
  • Kapton is extremely tough.  It has excellent abrasion, impact and cut through resistance, very high resistance to oxidative degradation, weathering, and all chemicals except strong bases.  Kapton also offers high dielectric strength and insulation resistance.  Kapton does not support combustion; even at extremely high temperatures, it decomposes slowly without visible burning.  It is also resistant to radiation. The individual conductors and outer jacket are insulated with Kapton Tape.
  • Suggested maximum operating temperature: 900°F (482°C) continuous 1000°F (538°C) single exposure {Impregnation maintained to 400°F (200°C)}
  • Fiberglass insulation, with the special binder impregnation, offers good moisture and chemical resistance, as well as good abrasion resistance.  Typical applications include aerospace, foundries, heat treating, plastics industry and a wide variety of other uses.
  • Hi-Temp Fiberglass - Suggested maximum operating temperature: 1300°F (704°C) continuous, 1600°F (871°C) single exposure {Impregnation maintained to 400°F (200°C)}
For more information about thermocouple wire insulation materials contact Duro-Sense Corporation by calling 310-533-6877 or visiting