AerOpak® Mineral Insulated Thermocouple

AerOpak®is a trade mark for Okazaki metal sheathed ceramic insulated cable and thermocouples. The AerOpak®construction result in thermocouples wires that are surrounded by a compacted mineral insulation (MgO) and contained in a sheath such as stainless steel or heat resisting steel. On the basis of this AerOpak® construction, a wide variety of otherwise difficult applications are possible. Compared with general-purpose (Protection tube type) thermocouples, sheathed thermocouples
have many advantages.

Basic thermocouple theory

A thermocouple is a closed Loop circuit that consists of two dissimilar metal wires welded together at both ends. When a temperature difference exists between the two junctions, thermal electromotive force (EMF) is generated and an electric current flows in the closed circuit. The direction and magnitude of the EMF generated depend upon the temperature of the two junctions and upon the materials making up the thermocouple, and are not affected by the size or length of the thermocouple wire. Temperature can be measured by knowing beforehand the change of EMF per degree change of temperature for a certain thermocouple.

Features and specifications of AerOpak®thermocouples

AerOpak® thermocouples have the following advantages over conventional protection tube or wire-insulator styles.

  1. A wide application in measurement
    Small diameter thermocouple is very useful for the place where space is at premium. AerOpak® construction is resistant to high pressure and also used at wide range of temperature from – 200 C to +1050 C.
  2. Quick response
    AerOpak® thermocouples have small heat capacity due to the small sheath size, The small thermal mass is highly sensitive to change in temperature and gives a very fast response.
  3. Easily bent for installation
    The ability to form AerOpak® thermocouples on a radius twice the sheath diameter makes for simple and on-the-spot installation into complex configurations.
  4. Long life span
    Contrary to conventional thermocouples which suffer from deterioration of electromotive force or wire disconnection, etc., AerOpak® thermocouples wires are insulated with chemically stable magnesium oxide, thus assuring a longer service life.
  5. Excellent mechanical strength and pressure resistance
    The composite construction is resistant to extremely high vibration levels, and by choosing appropriate sheath material, it is reliable to use in corrosive atmospheres and abnormally high or low temperatures,. Though it has small diameter, it can be withstand 3500kg/cm2 at a temperature of 650 C.
  6. Custom sheath outer diameter available
    Sheath outer diameter sizes between 0.15mm and 19.7mm can be provided.
  7. Custom long length
    Length are available up to a maximum of 400m. Maximum length is dependent upon the sheath outer diameter.
  8. Compatible with special needs
    We have our own factory for making many kinds of metallic sheathed cables, therefore, we can correspond to various needs from customers.
  9. Fabrication
    AerOpak® sheath can be welded, brazed and soldered without changing insulation resistance using normal care of the metals and thickness involved.
  10. Sheath anneal
    Sheath will receive a full solution anneal, corresponding to type of sheath material
  11. Storage and shipping
    Each length AerOpak® cable is sealed at both ends with a silicone resin or shrink or both. This can be removed (preferably in a dry atmosphere) by a sharp knife or razor. This seal is suitable for short duration air shipments. For sea shipments, it is suggested that both cable ends be glob welded.
  12. Surface finished
    Metallic, 32 micro inch RMS finish or smoother, slightly dull to bright or polish finish. Scratches or pits not to exceed 10% of wall thickness or 0.001 Inch, whichever is greater.