Thermocouple cables use different metallic alloys in the positive and negative conductors in order to measure temperature. Different types are made from different combinations of metals.
Compensating cable is of a different composition to extension cable and should only be used for joining thermocouples to their measuring instruments. Extension cable can be used for producing a thermocouple junction and for joining thermocouples to their measuring instruments.
These cables are available in single and multipair versions in a range of sizes and materials.
Thermocouple cables are limited in temperature by the rating of their insulation material.
| Thermocouple type | sheath colour | positive core | negative core |
|---|---|---|---|
| B extension (BX) | grey | platinum-rhodium (70/30) | platinum-rhodium (94/6) |
| E extension (EX) | violet | nickel-chromium (chromel) | copper-nickel (constantan) |
| J extension (JX) | black | iron (magnetic) | copper-nickel (constantan) |
| K extension (KX) | green | copper | copper-nickel |
| K compensating (KCB) | green | nickel-chromium (NiChro) | nickel-aluminium (NiAl) |
| N extension (NX) | pink | nickel-chromium-silicon | nickel-silicon (NiSil) |
| R extension (RX) | orange | copper | copper-nickel (low value) |
| R compensating (RCB) | orange | platinum-rhodium (87/13) | platinum |
| S extension (SX) | orange | copper | copper-nickel (low value) |
| S compensating (SCB) | orange | platinum-rhodium (90/10) | platinum |
| T extension (TX) | brown | copper | copper-nickel (constantan) |
| Colours according to IEC584.3: positive cores match the sheath, negative cores are always white. | |||
| Thermocouple cables – popular construction options | ||||||
|---|---|---|---|---|---|---|
| Common Formats: |
| Flat Single Pair (unscreened with oval shaped sheath) |
| Twisted Single Pair (unscreened and without sheath) |
| Screened Single Pair (overall foil with circular sheath) |
| Screened Multi-pair (individual &/or overall foil, circular sheath) |
| Steel wire armour (SWA) available on some types |
| Conductor Sizes: | Sheath Materials: |
| stranded 7/0.2mm (0.22mm²) | PVC (-30 to +70°C) |
| stranded 14/0.2mm (0.44mm²) | LSZH (-30 to +75°C or +90°C) |
| stranded 16/0.2mm (0.5mm²) | high-temp PVC (-30 to +105°C) |
| stranded 24/0.2mm (0.75mm²) | silicone (-50 to +180°C) |
| stranded 48/0.2mm (1.5mm²) | PTFE (-75 to +250/300°C) |
| solid 1/0.3mm (0.07mm2) | PFA (-75 to +250°C) |
| solid 1/0.5mm (0.2mm²) | varnished glass fibre (-60 to +350°C) |
| solid 1/0.8mm (0.5mm²) | ceramic fibre (0 to +1000°C) |
| solid 1/1.29mm (1.3mm²) | hi-temp glass fibre (-60 to +700°C) |
A printable selection guide is available here: Thermocouple compensating or extension cable.
For more available cables view the Products and Specifications page.
If the cable you require is not listed please contact us as we may still be able to help.
