Mineral insulated thermocouple
Durex Industries

Mineral insulated thermocouples are manufactured with compacted MgO insulation housed in a stainless steel or alloy sheath that protects the thermocouple element from the application environment. This construction provides an incredibly durable design that can be adapted to a wide variety of applications.
The compacted MgO construction offers superior life compared to other types of thermocouples due to the ability to withstand extreme thermal shock and prevent contamination of the element itself.
Mineral insulated thermocouples can be constructed to operate at temperatures up to 2400°F. Termination options for these sensors are wide ranging and include plugs mounted directly to the sheath, cast aluminum or iron terminal heads, and flexible leadwires.
Sheath diameters of .020" to .500" are available with various stainless steels or other alloys depending on the application and are provided in all standard ANSI calibrations. Mounting these sensors can be accomplished through use of compression fittings, fixed bushings, or mounting brackets.