Thermocouple sensors must be wired with right kind of materials between hot and cold junctions, in order to avoid measurement deviation caused by thermo voltages in connections of different materials. Cable types used are extension wires (X) or compensating cables (C).
Lapp Automaatio's stock items are silicon insulated compensating cables according to IEC 60584, with maximum temperature +180 °C. The wire structure of one pair cables for J, K and S type TC sensors is 2 × 1,5 mm².
Stock items are listed below:
| Product number | Designation | Number of cores and wire size | Colors +/–/sheath | Outer diameter mm |
|---|---|---|---|---|
| 903242 | NiCr/Ni 2G ST 2G K | 2x1.5 | grn/wht/grn | 7.50 (±0.15) |
| 1084278 | NiCr/Ni 2G ST 2G K | 3x(2x1.5) | grn/wht/grn | 9.50 (±0.15) |
| 911884 | NiCr/Ni 2G ST 2G K | 6x(2x1.5) | grn/wht/grn | 13.40 (±0.15) |
| 1084281 | NiCr/Ni 2G ST 2G K | 8x(2x1.5) | grn/wht/grn | 14.90 (±0.15) |
| 903256 | PtRh/Pt 2G ST 2G S | 2x1.5 | ora/wht/ora | 7.50 (±0.15) |
| 1002534 | PtRh/Pt 2G ST 2G S | 2x(2x1.5) | ora/wht/ora | 8.50 (±0.15) |
| 903257 | Fe/CuNi 2G ST 2G J | 2x1.5 SIL | bck/wht/bck | 7.50 (±0.15) |
| 1210658 | NiCrSi/NiSi 2G ST 2G N | 2x1.5 | pnk/wht/pnk | 7.50 (±0.15) |
Color short forms: bck = black, grn = green, ora = orange, pnk = pink, wht = white.
Other cable types and wire structures can be delivered on request.
Lapp Automaatio's stock items of cables for thermocouples are compensating cables.
TC = Thermocouple
Compensating temperature measurement is needed in the point where compensating or extension cable is changed to copper cable. This point - cold junction - can be located e.g. by a terminal block inside a field enclosure or by terminals of a transmitter. More details on page: How do TC sensors work?
Cold Junction Compensating with PR temperature transmitters
