THERMOCOUPLE

A thermocoupIe is a cIosed Ioop circuit that consists of two dissimiIar metaI wires weIded together at both ends. When a temperatune difference exists between the two junctions, thermaI eIectromotive force (EMF) is generated and an eIectric current fIows in the cIosed circuit. The direction and magnitude of the EMF generated depend upon the tempemture of the two junctions and upon the materials making up the thermocoupIe, and are not affected by the size or Iength of the thermocoupIe wire. Temperatune can be measured by knowing beforehand the change of EMF per degree change of temperature for a certain thermocouple. ln seIecting the right thermocouple for your particular application, you should pick one that is stable in performance over a long period of continuous use and which also meets your requirements as to temperature range, purpose, usage, accuracy needed, etc. Our standard thermocouples include types B, R, S, N, K, E, J and T all of which conform to the IEC. Also available are types W 5 R e / W 2 6 R e thermocouples. You can select the right thermocouple for your particular requirement from our product line.

Configuration

A thermocouple assembly contains a thermocouple element, protection tube, terminal head, insulators and mounting attachment.

1. Thermocouple Element

EIement types are shown below. The measuring junction (hot junction) is welded together.

2. Protection Tube

The tube, which has a mounting attachment and a terminal head, houses the element and insulators and protects them from envilonmental conditions. The right kind of tube material should be selected for the given application.

3. Teminal Head and Terminal Plate

The terminal head, in which the co mpensating Iead wire and thermocouple are connected, is available in the weather-proof (aluminum diecast), and also in other types of materials and shapes suitable for your particular application.

4. lnsulators

The insuIators and ceramic tubes insulate the element wires from each other and from the protection tube.

5. Mounting Attachment

The attachment connected to the protection tube is used to mount the thermocouple assembIy Standard Parts CataIog.