Nicr-Ni (Type K) temperature sensors

(Type K Thermocouple Ratings At 1200°C)

Hi everyone,
A thermocouple is a sensor used to measure temperature. Thermocouples are made of two wires made of different metals. These wires are welded together at one end to form a junction called a hot spot, which is where the temperature is measured. When the hot spot experiences a change in temperature, a millivoltage is generated. This signal is then calculated by a temperature controller to provide an accurate temperature reading.

The most common type of thermocouple we stock in various lengths with diameters of 3 & 6mm are the K and J types.

K Type Thermocouples
K Type Thermocouples are the most popular thermocouple temperature sensors on the market today. While more expensive than J Type Thermocouples, K Type is versatile in that it can withstand temperatures ranging from 0°C to 1260°C. This higher temperature range makes it much more useful in extreme heat than J Type, but its increased cost means it doesn't tend to beat J Type thermocouples in lower temperature ranges.

In addition to an increased temperature tolerance range, K Type Thermocouples have another advantage in resistance and capacitance – different metallic makeups. While J Type thermocouples are made of iron and constantan, K Type thermocouples are made of nickel/chrome alloy (chromel) and nickel/aluminum alloy (alumel), which provide better protection against iron limbs than J Type.

Therefore, K Type Thermocouples are excellent in oxidative environments and in environments with corrosive atmospheres or when immersed in an oxidizing or corrosive liquid. In fact, K Type Thermocouples work best in a clean oxidizing atmosphere, where a J Type can oxidize and be damaged. K Type thermocouples are also more useful at very high temperatures, up to 1260°C, and can accurately measure temperatures even at these temperatures.

However, their slightly increased cost compared to J Type thermocouples helps ensure that J Type thermocouples continue to be used in low-temperature applications and in non-oxidizing environments that are perfectly suited for temperature measurement. As temperature sensors, K type and J type thermocouples may be superficially similar, but they are suitable for a wide variety of applications.

It also demonstrates high stability at temperatures below zero and error limits are guaranteed at cryogenic temperatures, which is useful for the production and application of low temperature phenomena such as -150 °C. The average temperature range is between -185 °C to +300 °C, making it the best thermocouple for measuring low temperatures.