Watlow Mineral Insulated Thermocouple

  • Moisture and thermal shock protection
  • High temperature and pressure environments sustainable
  • Variety of sheath materials, diameters and lengths
  • XACTPAK flexible material


The Mineral Insulated Thermocouples from Watlow are fast-responding, durable and capable of handling high temperatures up to 2200°F.  This product features a special mineral insulation that protects thermocouples from moisture and thermoshock. Watlow MI thermocouples are offered in custom options such as special lead lengths, lead wires and terminations.

Additionally, these thermocouples are manufactured with XACTPAK®, Watlow’s trademark for metal-sheathed, mineral insulated (MI) thermocouple material. XACTPAK responds fast because the protective metal outer sheath allows the use of smaller diameter thermocouple conductors. The rock hard compacted MgO insulation further enhances the sensor’s ability to “read” temperature by transferring heat quickly to the measuring junction. The XACTPAK protecting sheath and compacted insulation outperforms bare wire thermocouple in most applications.

Typical Applications

Typical Applications are as follows: Heat treating, Furnaces/kilns, Turbines, Bearing temperature, Power stations, Steam generators, Diesel engines, Nuclear reactors, Atomic research, Jet engines and test cells, Rocket engines, Semiconductor manufacturing, Refineries/oil processing, Catalytic reformers, and Food processing.

We provide engineering and product support for your application.

Technical Documentation

Download PDF files:

Watlow Mineral Insulated Thermocouple Specification

Watlow Mineral Insulated Thermocouple Catalog