Mineral insulated thermo­couples

Mineral insulated thermocouples are used for temperature measurements between -200 until + 1,150 °C within gaseous and fluid mediums. A mineral insulated thermocouple consists out of jacket tube, thermo wires of thermo pair and magnesium oxide. The jacket material depends on the to be measured temperature: 1.4571 stainless steel up to 800 °C or 2.4816 Inconel up to 1,150 °C. Isolation of the internal wires consists out of high sealed magnesium. Thermo pair wires are standardized as isolated from the jacket. Mineral insulated thermocouples are available as single or double element.

This construction guarantees:

• high reliability due the special protection of the inner conductor
• fast reaction because of the high thermal conductibility of the magnesium oxide
• high mechanical resistance due to outer metal jacket

Mineral insulated thermocouple advantages:

• flexibility (minimum bending radius is 5x OØ of jacket wire)
• vibration proof
• fast reaction
• high electric strength, as well with small dimensions
• producible in large nominal lengths

Disadvantages:

• insulation resistance failure with humidity penetration (hygroscopic insulation material)
• cement pot head, 120 °C temperature max

Mineral insulated thermocouples are multifunctional. Most common application ranges are machinery and equipment constructions, polymer processing industries, ovens as well as chemical industries.