Knowledge
Symbols for types of compensating lead wires
Check the type and accuracy of the thermocouple and select the type.
| In combination You use. Thermocouple type |
Conductor material | JIS C 1610-1995 | JIS C 1610-2012 (IEC standard colour) |
Compensating contact Temperature (℃) |
Tolerance(μV) | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| ＋ | － | Symbol 1995 |
Color Category 1 |
Color Category 2 |
Symbol 2012 |
Color | Class 1 | Class 2 | ||
| J1 | J2 | J3 | ||||||||
| B | Copper | Copper | BC |  |
 |
BC | |
0～100 | – | – |
| R | Copper | Copper nickel alloy | RCA |  |
 |
RCA |  |
0～100 | – | ±30 |
| Copper | Copper nickel alloy | RCB |  |
 |
RCB | |
0～200 | – | ±60 | |
| S | Copper | Copper nickel alloy | SCA |  |
 |
SCA | |
0～100 | – | ±30 |
| Copper | Copper nickel alloy | SCB |  |
 |
SCB | |
0～200 | – | ±60 | |
| N | Nickel chrome alloy | Nickel silicon alloy | NX |  |
– | NX | |
-25～200 | ±60 | ±100 |
| Copper nickel alloy | Copper nickel alloy | NC |  |
– | NC | |
0～150 | – | ±100 | |
| K | Nickel chrome alloy | Nickel alloy | KX |  |
 |
KX | |
-25～200 | ±60 | ±100 |
| Iron | Copper nickel alloy | KCB |  |
 |
KCA |  |
0～150 | – | ±100 | |
| Copper | Copper nickel alloy | KCC |  |
 |
KCB | |
0～100 | – | ±100 | |
| E | Nickel chrome alloy | Copper nickel alloy | EX |  |
 |
EX | |
-25～200 | ±120 | ±200 |
| J | Iron | Copper nickel alloy | JX |  |
 |
JX | |
-25～200 | ±85 | ±140 |
| T | Copper | Copper nickel alloy | TX |  |
 |
TX | |
-25～100 | ±30 | ±60 |
| Note1） | Symbols for types of compensating lead wires shall be expressed in terms of the type of thermocouple used in combination and the material of the core wire. Symbols for symbols indicating extension type core wires composed of the same material as the thermocouple used in combination shall be C for symbols indicating compensating type core wires composed of different materials from the thermocouple used in combination. Symbols for compensating core wires shall be classified by A or B if they are classified by allowance or compensation contact temperature. |
| Note2） | Symbol KCA is a symbol KCB at the time of revision in 1995, which was called WX at the time of revision in 1981. Symbol KCB is a symbol KCC at the time of revision in 1995, which was called VX at the time of revision in 1981. |
