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 Type B 
 Temperature sensors 

High-temperature thermocouple for extreme applications up to 1800 °C, ideal for furnaces, metallurgy, and laboratory environments.

 Maximum precision
+/- 0,5°K

 Minimum temperature
600°C

 Maximum temperature
+1820°C

 Minimum dimensions
1 x 1 x 1

 Response time
Low

 Internal Resistance
High

 Linearity
High

Price
High

What is a Type B thermocouple ?Operating principleTechnical specificationsVoltage / Temperature CurveCompatibility / CompensationApplication areas

What is a Type B thermocouple?

The type B thermocouple is a high-precision temperature sensor based on two alloys of platinum and rhodium.

It is specifically designed to measure extreme temperatures (up to +1,820 °C) while providing excellent long-term stability.

It is the preferred choice for laboratories, industrial furnaces, and glassworks.

Operating principle

The type B exploits the Seebeck effect: when there is a temperature difference between the hot junction and the cold junction, a voltage (in mV) is generated.

Simplified formula:

E = S × (T_hot - T_cold)

where S is the Seebeck coefficient, specific to each type of thermocouple.

For type B:

S ≈ 10 µV/°C around 1,000 °C

The voltage produced is proportional to the temperature difference between the two junctions.

Technical specifications

Parameter Typical value
Measurement range +600 °C → +1 820 °C
Sensitivity 10 µV/°C to 1 000 °C
Tension at 1,000 °C ≈ 6,4 mV
Tension at 1,800 °C ≈ 13,8 mV
Materials Pt-30Rh / Pt-6Rh
Oxidation resistance Excellent
Response time (6 mm diameter sheath) 6 to 10 s
Reference standard IEC 60584-1, ASTM E230

Voltage/Temperature Curve

The type B curve is almost linear at high temperatures, and the voltage remains nearly zero between 0 °C and 100 °C, making this thermocouple unsuitable for low temperatures.

Compatibility / Compensation

The type B thermocouple is used in 2 wires, connected to a measuring instrument via a compensation or extension cable suitable for type B.

Application areas

🧱 Industrial furnaces, metallurgy, ceramics, glass

🔬 Reference and calibration laboratories

⚙️ High-temperature process control

🧪 Research in materials and high-energy chemistry




Should I choose a Type B thermocouple?

Strengths points

  • 🔥 King of High Temperatures
         → The type B measures up to +1,820 °C continuously without degrading — it is the choice for furnaces, glassworks, and melting laboratories.
  • ⚗️ Exceptional stability over time→ Thanks to its platinum-based alloys, drift is almost nonexistent even after thousands of hours at high temperatures.
  • 🧠 Reproducible precision
         → His performances are extremely consistent, making him a benchmark for industrial calibrations.
Thermocouple type B sensors

Weaknesses points

  • 💸 High price
         → Platinum and rhodium are expensive: this sensor is reserved for critical applications, not for everyday use.
  • 🌡️ Insensitive to low temperatures
         → Below 600 °C, the signal becomes too weak for a reliable measurement.
  • 🐢 Slow response time
         → The refractory sheath necessary to withstand high temperatures slows down the thermal response.

Useful information

Here is some useful information regarding Type B thermocouples.

(Reference: cold junction at 0 °C, IEC 60584-1 standard)

Temperature (°C) Tension (mV) Temperature (°C) Tension (mV)
600 0,291 1 200 5,891
700 0,944 1 300 6,965
800 1,708 1 400 8,136
900 2,586 1 500 9,413
1 000 3,584 1 600 10,809
1 100 4,703 1 700 12,324
1 180 5,600 1 820 13,820

💡 Between 0 and 600 °C, the voltage remains almost zero (< 0.3 mV), which is why it is not used for low temperatures.

Class Tolerance (°C) Usage area
 Description
Class 1 ±(0.5% of the value) 600 → 1 700 °C High precision
Class 2 ±(0.5% or ±2.5 °C, the greater of the two)** 600 → 1 700 °C Industrial standard
Class 3 – Not applicable The type B does not have a class 3 according to IEC
🔹 Even class 2 offers sufficient accuracy for the majority of industrial processes.

🔸 Example 1 – Calculation of the generated voltage

If the measured temperature is 1,200 °C,

and the cold weld is at 0 °C, then :

E = 5,891 mV

If the cold weld is at 25 °C, we correct with the equivalent voltage (~0.018 mV), so:

E_corrected = 5.891 - 0.018 = 5.873 mV

✅ Actual tension to read ≈ 5.87 mV


🔸 Example 2 – Calculating temperature from a measured voltage

Measured voltage: 10.809 mV (cold weld at 0 °C)

→ By consulting the IEC table, this value corresponds to:

T=1600°C

✅ Measured temperature ≈ 1,600 °C

The type B thermocouple produces a voltage of a few millivolts.

It therefore requires a precise differential amplifier, cold junction compensation, and a high-resolution analog-to-digital converter.

🔹 Typical components

Component
 Function
Thermocouple type B (Pt30Rh / Pt6Rh)
 Generate the Seebeck voltage
Differential amplifier (e.g., AD8495-B, INA333)
 Amplify the signal µV → V
Compensation sensor (NTC or integrated sensor)
 Measure the temperature of the cold weld
ADC 16–24 bits Convert the amplified signal
Microcontroller / data acquisition system
 Calculate the final temperature
🔹 Functional diagram (ASCII)
 [HOT JUNCTION]──(Thermocouple B)──[AMPLIFIER]──[ADC]──[µCONTROLLER]
                                      │
                                      └──(Compensation sensor)
💡 This setup ensures accurate measurement even at 1,800 °C, with an error of less than ±0.5 °C if properly calibrated.

 We integrate any sensor into any probe 

Smooth tube probe

 Smooth tube 

Waterproof probe

 Waterproof

Bayonet probe

 Bayonet

Slot probe

 Slot

Ambient probe

 Atmosphere

Head connection probe

Termal block

Stick-in probe

Stick-in

Thread probe

Thread

Contact probe

Contact

Jacketed probe

Jacketed

PCBA Design

PCBA design

Winding probe

Winding

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