Platinum-Rhodium Thermocouple Wires
Thermocouples are essential for temperature measurement and control in high-temperature environments, including the steel, glass, and semiconductor industries. ISHIFUKU manufactures high-purity platinum-rhodium thermocouple wires that deliver stable and accurate measurements, even under demanding conditions.
In addition to JIS-standard Type S, Type R, and Type B thermocouple materials, we offer ultra-fine wires with diameters of tens of micrometers and expendable thermocouple materials for rapid temperature measurement.
Key Features of ISHIFUKU's Platinum-Rhodium Thermocouple Wires
ISHIFUKU's platinum-rhodium thermocouple wires are manufactured using in-house refined high-purity platinum and rhodium, ensuring strict impurity control and excellent compositional uniformity. This results in stable thermocouple emf characteristics and reliable measurement accuracy over extended use.
Product lineup highlights:
- Standard wires — φ0.1 to 0.5 mm for Type S, Type R, and Type B thermocouples, available in Class 1, 2, and 3 tolerances per JIS C 1602:2015
- Ultra-fine wires — φ0.05 and φ0.06 mm for rapid temperature response
- Expendable thermocouple materials — for extremely short-duration measurements
- Custom solutions — tailored compositions, diameters, and welded assemblies available on request
Type S Platinum-Rhodium Thermocouple Wires
Type S thermocouple wires consist of a Pt-10%Rh (platinum-10% rhodium) positive wire and a pure Pt negative wire. They are widely used for high-precision temperature measurement in high-temperature environments such as furnaces, glass manufacturing, semiconductor processes, and laboratory applications.
ISHIFUKU supplies high-purity platinum and platinum-rhodium bare wires for Type S thermocouples, manufactured to support stable thermocouple emf characteristics and reliable measurement accuracy. For φ0.5 mm wires, the recommended continuous-use limit is 1,400°C, with an upper temperature limit of 1,600°C for short-term use.
| Type symbol | Positive wire | Negative wire | Tolerance classification | ||
|---|---|---|---|---|---|
| Class 1 | Class 2 | Class 3 | |||
| S | Pt-10%Rh | Pt | 0 to less than 1,100℃: ± 1℃ 1,100 to less than 1,600℃: ± [1 + 0.003× (t-1,100)] |
0 to less than 600℃: ± 1.5℃ 600 to less than 1,600℃: ± 0.0025× t |
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Type R Platinum-Rhodium Thermocouple Wires
Type R thermocouple wires consist of a Pt-13%Rh (platinum-13% rhodium) positive wire and a pure Pt negative wire. They are suitable for accurate temperature measurement in high-temperature industrial processes, including heat treatment furnaces, glass manufacturing, and semiconductor-related applications.
ISHIFUKU supplies high-purity platinum and platinum-rhodium bare wires for Type R thermocouples, designed to provide stable thermocouple emf characteristics and reliable measurement accuracy. For φ0.5 mm wires, the recommended continuous-use limit is 1,400°C, with an upper temperature limit of 1,600°C for short-term use.
| Type symbol | Positive wire | Negative wire | Tolerance classification | ||
|---|---|---|---|---|---|
| Class 1 | Class 2 | Class 3 | |||
| R | Pt-13%Rh | Pt | 0 to less than 1,100℃: ± 1℃ 1,100 to less than 1,600℃: ± [1 + 0.003× (t-1,100)] |
0 to less than 600℃: ± 1.5℃ 600 to less than 1,600℃: ± 0.0025× t |
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Type B Platinum-Rhodium Thermocouple Wires
Type B thermocouple wires consist of a Pt-30%Rh (platinum-30% rhodium) positive wire and a Pt-6%Rh (platinum-6% rhodium) negative wire. They are suitable for temperature measurement in extremely high-temperature environments, such as steel, glass, ceramics, and other industrial furnace applications.
ISHIFUKU supplies high-purity platinum-rhodium bare wires for Type B thermocouples, designed to support stable thermocouple emf characteristics and reliable high-temperature measurement. For φ0.5 mm wires, the recommended continuous-use limit is 1,500°C, with an upper temperature limit of 1,700°C for short-term use.
| Type symbol | Positive wire | Negative wire | Tolerance classification | ||
|---|---|---|---|---|---|
| Class 1 | Class 2 | Class 3 | |||
| B | Pt-30%Rh | Pt-6%Rh | - | 600 to less than 1,700℃: ± 0.0025× t |
600 to less than 800℃: ± 4℃ 800 to less than 1,700℃: ± 0.005× t |
Resistance Wires
Overview
ISHIFUKU offers resistance elements for platinum resistance temperature detectors (RTDs) and high-purity silver wire for use as lead wires. We utilize advanced refining and processing techniques to ensure strict purity control.Features
ISHIFUKU provides two types of platinum resistance wires with different resistance-temperature characteristics.
Resistance wire (platinum wire for resistance temperature detectors)
| Resistance wire for temperature sensors | Platinum temperature sensors (JIS C 1604:2013) | ||
|---|---|---|---|
| Product name | Resistance ratio (R100/R0) | JIS symbol | Resistance ratio (R100/R0) |
| R850 resistance wire | 1.3845 to 1.3865 | Pt100 | 1.3851 |
| R916 resistance wire | 1.3916 to 1.3927 | - | - |
FAQ About Thermocouple Wires
ISHIFUKU offers platinum and platinum-rhodium bare wires in standard diameters of φ0.1, 0.2, 0.3, 0.4, and 0.5 mm for Type S, Type R, and Type B thermocouples. We can also provide ultra-fine wires with diameters of tens of micrometers, such as φ0.05 and φ0.06 mm, to meet specific application requirements.
Yes. ISHIFUKU can provide the wires either as bare positive and negative wires or as a welded thermocouple assembly, depending on the customer's requirements.
ISHIFUKU recommends using both the positive and negative wires manufactured by ISHIFUKU. When ISHIFUKU's wires are combined with wires from other manufacturers, the thermocouple emf characteristics are not guaranteed.
Each production lot is inspected by measuring thermocouple emf at the freezing point and specified fixed points, then evaluating the results against the reference electromotive force defined in JIS C 1602:2015.
Use near the short-term use limit should be limited to extremely short periods. In general, thermocouple wires should be used at or below the recommended continuous-use limit to help maintain stable performance and service life.
When assembling the wires into insulating tubes, protective tubes, terminals, or other components, the wires should not be subjected to mechanical stress. Excessive stress may shorten the service life of the thermocouple. Care should also be taken to avoid excessive force or impact on the welded junction as it is a delicate part that affects measurement accuracy.
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