Construction :
An MI thermocouple is made up of:
Thermocouple wires (e.g., Type K, J, T, N, R, S, or B) that generate a temperature-dependent voltage.
Mineral insulation, typically high-purity magnesium oxide (MgO), which provides excellent electrical insulation and good thermal conductivity.
Metal sheath (such as stainless steel, Inconel, Hastelloy, or Monel) that protects the assembly from mechanical damage, corrosion, pressure, and vibration.
Junction Types :
Grounded junction: Fast response, junction welded to the sheath
Ungrounded junction: Electrically isolated from the sheath, reduced electrical noise
Exposed junction: Very fast response, less protection from environment
Applications
Industrial furnaces and kilns
Power generation and petrochemical plants
Aerospace and gas turbines
Nuclear and research facilities
Food processing and pharmaceuticals
General process control where durability and accuracy are critical
Key Features :
Wide temperature range (approximately 200 C to +1250 C, depending on type and sheath material)
Fast response time due to small diameter and good thermal conductivity
High mechanical strength and resistance to vibration
Excellent insulation resistance, even at high temperatures
Flexible and formable, can be bent to suit installation requirements
Long service life in aggressive environments