RS Pro IEC Mineral Insulated Type J & Type K Thermocouple with KNE Terminal Head

From RS Pro a range of type J and Type K thermocouple temperature sensors or probes that conform to IEC 584 standards. These thermocouple temperature probes have a durable construction and feature a 310 stainless steel mineral insulated flexible sheath that can be bent and formed to suit a wide range of applications. The thermocouple has an insulated hot junction for a reduction in electrical interference. One end of the thermocouple is terminated with a compact KNE terminal head the gives protection to the connections

How does a Thermocouple Work?

A thermocouple is a sensor used to measure temperature in a range of different processes and consists of two wire legs made from different metals joined together at their two ends to form two junctions. The hot, or measuring junction is connected to the body whose temperature is going to be measured. The cold junction or reference junction is connected to a body of known temperature. When the measuring junction is placed on something hot a voltage or potential difference between this and the reference junction occurs. This voltage can then be converted into a temperature measurement using thermocouple reference tables. This process is also known as the Seebeck Effect

What is an Insulated Junction?

An insulated or ungrounded junction is where the thermocouple wires are welded together and fully covered by but isolated from the outer protective sheath. The advantage of this is that there is a reduction in electrical interference and a stable reading.

What is Mineral Insulation?

Mineral insulation is used to insulate the thermocouple wires from one another and from the metal sheath that surrounds them. The sheath is filled with a highly compacted magnesium oxide powder that prevents the conductors from making contact with one another other than at the fixed junction. The high density of the mineral powder enables the thermocouple to have a rapid response as it promotes a fast heat transfer between the conductor and the sheath. Mineral insulation also helps to protect the thermocouple wire from environmental damage including corrosion, prevents electrical interference and allows the cable to be flexible whilst maintaining its mechanical strength

What is a Terminal Head?

A terminal head is designed to provide access to the connections between the sensor and instrument wiring and providing protection from the elements. The KNE terminal head on this thermocouple has an aluminium finish and is IP67 rated. Built into the head is a compensating terminal block and an M20 cable gland. The probe is simply pushed into the head via the probe glands and the flange. The terminating head also features a screw cap and retaining chain

Key Features and Benefits

• Insulated hot junction for reduced electrical interference
• Mineral insulation for flexibility and durability and high performance
• Conforms to IEC 584 standards
• Flexible, can be bent into shape for easy installation
• Stainless steel 310 probe sheath for resistance to corrosion and oxidation
• 6 mm diameter probe
• IP67 rated termination head for connection access and protection
• Simple push-in process via probe glands and flange
• M20 cable gland

Applications

Type K Thermocouples (Nickel-Chromium / Nickel-Aluminium) are the most common type of thermocouple and are both accurate and flexible with a wide temperature range. Typical applications for these mineral insulated Type-K thermocouple probes include heat exchangers, power stations, brick and cement kilns, heat treatment and annealing furnaces, thermostats, food thermometers, vehicle diagnostics and in laboratories

Type J Thermocouples (Iron-Constantan) have a smaller temperature range and a shorter lifespan at higher temperatures than the Type K but have the same reliability. Type J thermocouples are ideal for monitoring the temperatures of inert materials and in vacuum applications. Applications include heat processes such as the manufacturing of plastic and resin and in electrical furnaces