Type K Thermocouple Extension Wire Flexible Durable Stranded Construction for Industrial Environments
NiCr-NiSi (Type K) thermocouple wire is commonly used for temperature measurement in various industrial applications. The "NiCr" refers to the nickel-chromium alloy used for the positive leg of the thermocouple, while "NiSi" refers to the nickel-silicon alloy used for the negative leg. Type K thermocouples are among the most widely used thermocouples because of their broad temperature range and relatively low cost.
Compensating wire is used to extend the thermocouple’s measuring range and to prevent errors from ambient temperature effects. It is often made of materials that mimic the electrical properties of the thermocouple for a limited distance.Type K extension wire is used to extend the connection between the thermocouple probe and the measurement device without introducing significant measurement errors. The extension wire is designed to have the same thermoelectric properties as the thermocouple it is paired with.
The compensating and extension wires are not intended for direct temperature measurement, but rather for signal transmission, so they are usually made of materials that closely match the thermoelectric characteristics of the thermocouple.
Color codes of thermocouple wire (K type)
Positive wire is yellow, negative wire is red.
Thermocouple temperature range and tolerance
Themcouple No. indexing |
Compensation wire type |
Usag classification |
Measuring junction temperature/
℃
|
Standardc EMF value/μV |
Presion grade |
General grade |
Tolerance/μV |
Thermal EMF range/μV |
Tolerance/μV |
Thermal EMF range/μV |
K |
KX,KCA OR KCB |
G |
-25 |
-968 |
±40 |
-924~-1012 |
±80 |
-880~-1056 |
100 |
4096 |
4052~4140 |
4008~4184 |
H |
-25 |
-968 |
±40 |
-924~-1012 |
±88 |
-880~-1056 |
100 |
4096 |
4052~4140 |
4008~4184 |
200 |
8138 |
8094~8182 |
8050~8226 |
Compensating Wire Reciprocating Resistance
Compensation wire type |
Reciprocating Resistance (Ω/m20℃ less than) |
0.2mm² |
0.5mm² |
1.0mm² |
1.5mm² |
2.5mm² |
KCA |
3.5
|
1.1 |
0.7 |
0.47 |
0.28 |
KCB |
2.6 |
1.04 |
0.52 |
0.35 |
0.21 |
KX |
5.5 |
2.2 |
1.1 |
0.73 |
0.44 |
Key features of NiCr-NiSi (Type K) Thermocouple Compensating and Extension Wire:
1. Material Composition:Positive Leg (NiCr): Made of a nickel-chromium alloy, which is highly resistant to oxidation and performs well in high-temperature environments.Negative Leg (NiSi): Made of a nickel-silicon alloy that complements the positive leg and contributes to stable thermoelectric properties.
2. Temperature Range:Type K thermocouple wire can typically measure temperatures from -200°C to 1372°C (-328°F to 2502°F). Extension and compensating wires typically match the temperature range of the thermocouple itself.
3. Electrical Characteristics:The thermoelectric voltage produced by the Type K wire increases with temperature.
The wire pairs (NiCr-NiSi) generate a predictable and stable voltage over a wide temperature range, which is essential for accurate temperature measurement.
4. Resistance to Corrosion and Oxidation:NiCr (Nickel-Chromium) and NiSi (Nickel-Silicon) alloys are highly resistant to oxidation and corrosion, making them ideal for high-temperature and harsh environments.
This resistance ensures long-term stability and reliability, even in extreme conditions.
5. Durability and Flexibility:
Type K compensating and extension wires are designed to be flexible, allowing easy installation and handling in tight or complex spaces.
They are also durable enough for continuous use in industrial applications, ensuring long service life.
6. Compatibility with Thermocouple Probes:Extension wires and compensating wires are designed to be compatible with Type K thermocouples, ensuring seamless integration for accurate temperature measurements.
Compensating wire helps minimize errors due to temperature differences between the thermocouple and measurement device.
7. Accuracy:Thermocouple Extension Wire is designed to have the same thermoelectric properties as the thermocouple itself, ensuring minimal measurement error when the wire is used for signal transmission.
Proper calibration of the extension wire is crucial to maintain the accuracy of temperature readings.
8. Cost-Effective:Type K thermocouples and their associated compensating and extension wires are cost-effective solutions for temperature measurement compared to other types of thermocouples (e.g., Type R or Type S).
9. Standardization and Industry Use:Type K thermocouples and extension wires are standardized, widely used in industries such as automotive, chemical processing, food and beverage, electronics manufacturing, and metallurgy.
Extension wires typically comply with industry standards, such as ASTM E230 and IEC 60584.
10. Ease of Use and Installation:Extension wires are designed for simple installation, typically with color-coded insulation (for Type K, yellow insulation with a green stripe for the negative leg), ensuring easy identification during installation and maintenance.
11. Reduced Measurement Errors:Compensating wire helps reduce measurement errors due to the temperature difference between the thermocouple junction and the instrument. It’s typically used when the thermocouple is located far from the measuring device.
12. Insulation:Insulation material: Common insulation materials include PVC, Teflon, and Fiberglass, which are chosen based on the operating environment and temperature range.These materials ensure safe operation and protect the wire from mechanical wear, chemical exposure, or environmental damage.
13. Safety:Type K extension and compensating wires are often designed to meet safety standards and ensure proper insulation to prevent short circuits and electrical hazards.
These features make NiCr-NiSi Type K thermocouple compensating and extension wires suitable for a broad range of applications where accurate and reliable temperature measurements are required.
Applications:
- Industrial Temperature Monitoring: Found in furnaces, kilns, ovens, and exhaust systems.
- Chemical and Pharmaceutical Industries: Used for monitoring processes in reactors and distillation columns.
- Food and Beverage: Common in temperature monitoring for cooking and pasteurization
Considerations:
- Accuracy: Type K thermocouples are quite accurate within their specified range, but care should be taken when choosing the right type of wire, as poor-quality extension or compensating wires can introduce errors.
- Temperature Calibration: Type K wires must be properly calibrated, and the connection points should be kept free of contaminants that could alter the thermoelectric characteristics.


