Type E | GUILCOR SENSORS

Type E
Temperature sensors

High-sensitivity thermocouple delivering accurate measurements at low to moderate temperatures, ideal for cryogenic and industrial use.

Maximum precision
+/- 1,5°K

Minimum temperature
-200°C

Maximum temperature
+900°C

Minimum dimensions
0,5 x 30 x 3

Response time
High

Internal Resistance
Medium

Linearity
High

Price
Medium

What is a Type E thermocouple ?

The type E thermocouple combines nickel-chrome (Chromel) and nickel-constantan (Constantan).

It is distinguished by its high sensitivity — the highest among common thermocouples — with approximately 68 µV/°C.

This makes it a very precise sensor for low temperatures, often used in laboratories, cryogenic systems, and precision testing devices.

Operating principle

Like all thermocouples, type E relies on the Seebeck effect: a temperature difference between the hot junction and the cold junction generates a measurable voltage.

E = Se × (T_hot - T_cold)

For type E:

S_E ≈ 68 µV/°C (around 0 °C)
→ which is about 6.8 mV for a 100 °C difference.

It produces about 61 mV at 1,000 °C, which is a sensitivity 30% higher than type K.

Technical specifications

Parameter	Typical Value
Measurement range	−270 → +1 000 °C
Sensitivity	68 µV/°C to 0 °C
Tension at 1,000 °C	≈ 61,0 mV
Linearity	±0.4 °C over the useful range
Materials	Chromel (NiCr) / Constantan (CuNi)
Oxidation resistance	Medium
Response time (6 mm diameter sheath)	1 s (liquid) / 3 s (air)
Reference standard	IEC 60584-1, ASTM E230

Voltage / Temperature Curve

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

The relationship between temperature and the generated voltage is nearly linear over the useful measurement range (−200 to +900 °C).

Here is an overview of the typical curve 👇

📈 General behavior:

From −200 °C to 0 °C → negative voltage, rapid variation (~−8.8 mV to 0 mV)
From 0 °C to 900 °C → positive voltage, nearly linear (~0 to +55 mV)
Average slope: ≈ 68 µV/°C

💡 This linearity simplifies the voltage ↔ temperature conversion and reduces calculation errors in digital systems.

Compatibility / Compensation

The E type requires a cold weld compensation above ±1 °C of ambient variation.

It is compatible with most SPI/I²C measurement modules (MAX31855-E, MAX6675, AD8495E, etc.).

Application areas

🧊 Cryogenics and cold rooms (-200 °C)

🧪 Laboratories and precision test benches

⚙️ Scientific and thermal instrumentation

🧱 Light industrial applications up to 900 °C

🚀 Aerospace instrumentation / light propulsion

Should I choose a Type E thermocouple ?

Strengths points

⚡ Ultra-sensitive, even in the cold
→ The type E reacts to the slightest variation: perfect for fine measurements where other sensors are still inactive.
🎯 Powerful and precise signal
→ Its high output amplitude limits errors due to electrical noise a real asset for digital measuring devices.
🧊 Cut for the negative
→ It remains stable and usable down to −200 °C, where K or J types begin to drop off.

Weaknesses points

🔥 Bad companion of high temperatures
→ Beyond +900 °C, its accuracy drops and its conductors wear out quickly.
💨 Sensitive to oxidation
→ The Chromel wire does not like humidity or oxidizing environments; it is better to protect it with a suitable sheath.
🔌 Limited compatibility
→ Less common than other models, it requires specifically calibrated type E electronics to fully realize its potential.

Useful information

Here is some useful information regarding Type E thermocouples.

Temperature ↔ Voltage Table (mV vs °C)

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

Temperature (°C)	Tension (mV)	Temperature (°C)	Tension (mV)
−200	−8,825	200	11,486
−100	−4,387	400	23,842
0	0,000	600	36,256
100	5,865	800	48,837
200	11,486	1 000	61,016

💡 Type E generates a voltage of about 61 mV at 1,000 °C, which is the highest of all standard thermocouples.

Accuracy classes (IEC 60584-1)

Class	Tolerance (°C)	Operating temperature range (°C)	Typical usage
Class 1	±1,5 K	−40 → +800 °C	High precision
Class 2	±2,5 K	−200 → +900 °C	Industrial standard
Class 3	±2,5 K	−270 → +40 °C	Low temperature measurements (cryogenics)

🔹 Class 1 offers the best accuracy over a wide range, often used in scientific calibration.

Application example – Voltage/Temperature calculation

🔸 Example 1 – Calculation of the generated voltage

Measured temperature = 600 °C

Cold weld = 25 °C

E_measured = E(600) - E(25)

E_measured = 36.256 - 1.613 = 34.643 mV

✅ Measured voltage ≈ 34.64 mV

🔸 Example 2 – Calculating temperature from a voltage

Measured voltage = 11.486 mV

Cold junction at 0 °C

→ Referring to the IEC table, this corresponds to:

T=200°C

✅ Measured temperature ≈ 200 °C

Integration diagram in an electronic system

The type E thermocouple generates a voltage of a few tens of millivolts. It must be connected to a precise differential amplifier, with cold junction compensation and a high-resolution ADC (≥ 16 bits).

🔹 Typical components

Component	Function
Thermocouple type E (Chromel–Constantan)	Seebeck voltage source
Instrumentation amplifier (e.g. AD8495E, MAX31855E)	Amplify the differential tension
Compensation sensor (NTC or internal sensor)	Correct the reference temperature
ADC 16–24 bits	Analog-to-digital conversion
Microcontroller	Linearization, display, final calculation

🔹 Functional diagram (ASCII)

 	 [Hot junction]────┬────(+) Amplifier
                      │
                      └────(−) Amplifier
                              │
                           [ADC 24 bits]
                              │
                      [Microcontroller]
                              │
                   [Cold welding compensation]

💡 Thanks to its high sensitivity, type E is ideal for precise measurements at low temperatures while remaining economical and robust.