Luminex 993(tm) (magnesium oxide) combines physical land electrical properties that make it suitable for the manufacture of cartridge heaters, thermocouples and heating elements. It has high volume resistance at elevated temperatures, low sulfur content and low moisture absorption. The material can be applied in a thin layer between the sheath and the conductive wires of the micro cartridge, yet it still performs with good electrical insulating properties. The reduced sulfur content reduces the likelihood of corrosion when in contact with some metals, and the material will not distort as a result of swelling from moisture absorption during annealing. It has been engineered to be compatible with nickel-chrome alloys.