Prongs and inserts match thermocouple calibrations to maintain sensing accuracy. Alloy and polarity are identified by symbols molded into body. Molded from a glass filled thermoset compound for high strength, these connectors are color coded to thermocouple calibration and can be used in ambient temperatures of a continuous 400 degrees Fahrenheit and an intermittent 500 degrees Fahrenheit. High temperature connectors are all color coded 'Red,' with an ambient temperature of a continuous 800 degrees Fahrenheit and an intermittent 1,000 degrees Fahrenheit. Inserts have a spring loaded collet assuring full positive contact. The negative insert is larger preventing mismatching.
For ANSI platinum or tungsten calibrations, extension grade alloys are used.