Basic Materials
Type T thermocouple (copper-nichrome): Positive electrode: pure copper; Negative electrode: copper-nickel alloy (nichrome)
Type K thermocouple (nickel-chromium - nickel-silicon / nickel-aluminum) Positive electrode: nickel-chromium alloy; Negative electrode: nickel-silicon alloy.
Comparative Analysis by Item
1.Temperature measurement range
T-type: Temperature measurement range -200℃ ~ +350℃
Good at measuring temperatures at low and normal levels. Once the temperature exceeds 350℃, the copper wire will easily oxidize and become brittle and unusable. It cannot be used at high temperatures.
K-type: Temperature measurement range -200℃ ~ +1200℃
Can handle both high and low temperatures. It excels in high temperatures. It can measure temperatures as high as 500℃ or 900℃. It is the most commonly used universal model in industry.
2.Temperature measurement accuracy
T-type > K-type: The T-type has better overall linearity and stronger thermoelectric potential stability. It has extremely small errors in the low-temperature range and is the highest precision level among commonly used thermocouples. When measuring temperatures ranging from 70 to 200 degrees or even higher, the T-type provides more accurate readings with smaller fluctuations. It is the preferred choice for laboratories and precise temperature measurement. The K-type has sufficient accuracy for normal applications, but its low-temperature accuracy is slightly inferior.
3.Antioxidant properties and durability
High-temperature environment: K type outperforms C type. Copper itself is not resistant to high temperatures. When the T type is used at 300℃ for a long time, it极易 oxidizes and turns black, resulting in inaccurate signal drift. The K type nickel-based alloy is resistant to high temperatures and oxidation, and can maintain stability in the furnace and during heat treatment under high-temperature conditions.
Damp and normal-temperature environment： T type is more stable. In normal-temperature and damp environments, the T type is more resistant to corrosion and has better control over signal drift, and is less likely to experience temperature fluctuations.
4. Anti-interference and Stability
T-type: Extremely strong low-temperature stability, even slight temperature changes can be accurately detected;
K-type: Excellent medium-high temperature stability, the K-type is almost always the preferred choice for operations above 500℃; however, for small-scale temperature measurements within 200℃, the error is slightly larger than that of the T-type.
5. Cost price
The T type contains pure copper, and the raw materials are more expensive. The unit price of the same specification wire is higher than that of the K type; the K type has a large production volume, excellent versatility, and the highest cost performance. It is the most affordable and easiest to purchase on the market.
Applicable scenarios
T-type thermocouple wire
Low-temperature equipment, cold storage, cold chain temperature measurement
Laboratory instruments, environmental test chambers, precision thermostatic boxes
Food baking, pharmaceutical sterilization, small constant-temperature ovens
Precise electronics, semiconductor low-temperature detection (requiring precise temperature measurement) - for projects with high precision requirements, the T-type is the main recommendation. This applies to temperatures ≤ 350℃.
K-type thermocouple wire
Heat treatment furnaces, quenching furnaces, kilns, injection molding barrels, die-casting high-temperature equipment
Boilers, hot air ducts, industrial high-temperature drying lines
If the temperature exceeds 350℃, K-type is highly recommended.
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