Thermocouple Connectors ensure the Temperature measurement signal (millivolts) from the thermocouple sensor or lead wire is accurately transmitted to the display or control Instrumentation.
The 3 Things you should know in selecting the correct thermocouple connector.
1 - Ensure the Thermocouple Alloys within the connector Match those in the thermocouple sensor and or lead wires. It sounds very basic, although have seen well established organizations make this mistake and the resulting issues.
- 9 Different pairings of Thermocouple Alloys are used in the primary thermocouple connectors. It is common for these alloy pairs to be referred as Calibrations and use letters to designate the type of thermocouple.
- J, K, T, E, and N calibrations represent the most commonly used designs, sometimes referred as Base Metal thermocouples. Type C, R/S, U (B) thermocouples are utilized in much more specific, and many times higher temperature ranges or applications.
2 - A Color Coding system is used to help identify and match the connectors to the thermocouple sensors and wire. This Coloring System can be confusing and there are several specific important points to understand in this methodology.
- The USA color coding is Different than the international guidelines and other countries across the globe.
- The thermocouple wire leads you attach to the connector achieved is primarily achieved by Coloring the Insulation. Typically these insulations are high temperature plastics or fibers.
- The IEC (International Electrotechnical Commission) match the insulation color of the Positive thermocouple wire and the color of the outer jacket insulation to the color of the Thermocouple Connector.
- The USA or ANSI has some Exceptions to the insulated thermocouple wire color code system.
- For example thermocouple grade wire has a Brown colored outer insulation jacket, although the color code on Extension Grade thermocouple wire will match the connector with one exception
- Type J thermocouple connectors are Black although the insulation on the positive wire is White.
- Again Thermocouple Color Codes can be confusing and we provided a chart and other details in this document along with other technical reference on the Evolution Sensors website.
3 - The Functional Temperature range of the thermocouple connector is a Critical selection point to consider in your temperature measurement application.
- The metal alloy pins within the thermocouple connector can be capable of operating temperatures from Below Zero to above 2,000F.
- The Functional temperature range of thermocouple connector is determined by the Connector Body Materials.
- These materials are typically Thermoplastics, Thermosets or Ceramics providing an overall range from - 40 F to 1200 F (-40 C to 650 C). Each material provides specific temperature range and mechanical capabilities along with cost considerations.