Description
B Type Thermocouple is a simplex ceramic tube thermocouple featuring a Pt30%Rh / Pt6%Rh (Platinum-30% Rhodium / Platinum-6% Rhodium) sensing element. Unlike Type S and Type R, which use pure platinum as one conductor, Type B employs platinum-rhodium alloys for both conductors. This dual-rhodium construction provides improved structural stability and greater resistance to grain growth and embrittlement during prolonged exposure to extreme temperatures, making it the preferred choice for continuous service between 600°C and 1704°C.
To protect the noble metal element in severe furnace environments, the thermocouple incorporates a double ceramic protection system using 99.7% high-purity Ker-710 alumina. The twin-hole inner ceramic tube electrically insulates the thermoelement, while the outer ceramic protection tube shields it from mechanical damage and contamination. An SS310 holding tube supports the ceramic assembly outside the hot zone, and a weatherproof die-cast aluminium terminal head with IP65 protection safeguards the electrical connections in industrial environments.
Because the cost of platinum and rhodium alloys is significant and directly linked to precious metal markets, measurement confidence is essential. For this reason, the ABHS can be supplied with calibration certificates issued through Aavad Instrument’s NABL-accredited calibration laboratory, providing nationally traceable calibration documentation for applications where quality assurance and process validation are required.
When industrial furnace temperatures exceed 1500°C, selecting the correct thermocouple becomes critical for maintaining measurement accuracy, process stability, and sensor life. While Type S and Type R thermocouples are widely used in high-temperature applications, Type B thermocouples are specifically engineered for ultra-high-temperature environments, offering the highest continuous operating range among standard thermocouple types.
Key Features
-
Dual-Rhodium Platinum Alloy Construction ($text{Pt30%Rh / Pt6%Rh}$) Eliminates pure platinum grain growth to resist embrittlement and wire sagging up to 1704°C.
-
Widest Ultra-High Temperature Capability Continuous, stable measurement performance across the 600°C to 1704°C operating window.
-
Double Ker-710 High-Purity Ceramic Assembly Impervious 99.7% alumina ceramic sheath shields platinum wires from furnace gas contamination.
-
Traceable NABL Accredited Calibration Certification Verified against national measurement standards to satisfy strict ISO quality control audits.
-
SS310 Metallic Support Holding Tube Provides structural reinforcement and mounting stability where the sensor enters the furnace wall.
-
Weatherproof IP65 Aluminum Enclosure Heavy-duty die-cast terminal head seals wiring connections against dust, moisture, and ambient heat.
-
Negligible Cold-Junction Drift Near Ambient Output voltage between 0°C and 50°C is exceptionally low, often eliminating the need for cold-junction compensation in standard setups.
-
Self-Powered Passive Signal Loop Converts process heat directly into a linear millivolt loop signal without requiring excitation voltage.
Applications
-
Blast Furnaces and Electric Arc Steelmaking Critical thermal tracking in molten steel processing, tundishes, and ladle refining stations above 1500°C.
-
Glass Melting Tanks and Forehearth Crowns Continuous measurement in high-temperature glass tanks, refractory crowns, and feeder channels.
-
Ceramic, Refractory, and Brick Kilns Precision temperature control during high-temperature sintering, firing, and refractory testing cycles.
-
Petrochemical and Gasification Plants Monitoring high-heat thermal reactors, incinerators, and synthesis gas units.
-
Research Laboratories and High-Temperature Test Benches Serving as primary temperature standards and reference sensors for ultra-high-heat research.
Datasheet
FAQs
1. What is a B Type Thermocouple?
A B Type Thermocouple is a noble metal temperature sensor manufactured using Platinum-30% Rhodium (Pt-30Rh) and Platinum-6% Rhodium (Pt-6Rh) conductors. It is specifically designed for continuous temperature measurement in extremely high-temperature industrial processes, providing exceptional stability, accuracy, and reliability at temperatures up to 1704°C.
2. Why choose a B Type Thermocouple instead of Type S?
Type B Thermocouples are generally preferred for applications operating above 1500°C because their dual platinum-rhodium construction provides superior long-term stability, improved resistance to grain growth, and reduced calibration drift compared with thermocouples that use pure platinum as one of the conductors, such as Type S. This makes Type B ideal for continuous operation in extremely high-temperature furnaces and kilns.
3. What is the maximum temperature of a B Type Thermocouple?
The ABHS B Type Thermocouple is designed for continuous operation from 600°C to 1704°C, making it suitable for some of the most demanding high-temperature industrial applications, including glass manufacturing, steel production, ceramic processing, and laboratory furnaces.
4. What is the difference between Type B, Type R, and Type S Thermocouples?
Type B, Type R, and Type S are all noble metal thermocouples but differ in alloy composition and operating temperature range. Type S is widely used for applications up to approximately 1500°C, Type R offers similar high-temperature performance with a different platinum-rhodium alloy composition, while Type B provides the highest continuous operating capability, extending up to 1704°C, with excellent long-term stability at extreme temperatures.
5. Why are Ceramic Protection Tubes used with B Type Thermocouples?
High-purity ceramic protection tubes electrically insulate the platinum-rhodium thermoelements while protecting them from contamination, oxidation, thermal shock, and mechanical damage in extreme furnace environments. Ceramic protection improves measurement reliability, extends sensor life, and ensures accurate performance during prolonged exposure to very high temperatures.
6. Can a B Type Thermocouple be customized?
Yes. Aavad Instrument Pvt. Ltd. B Type Thermocouples are manufactured to meet specific industrial requirements. We offer customized insertion lengths, ceramic protection tubes, single or double ceramic protection, flange sizes, process connections, terminal head configurations, and application-specific designs to ensure reliable performance in high-temperature furnaces, kilns, glass plants, steel industries, and research laboratories.
