MIMS - Mineral Insulated Metal Sheath Thermocouples:

Description:

There are many types of thermocouples available on today's market. Each has its own particular advantages and disadvantages. In some cases Thermocouples are designed for specific measurement problems. In other cases, thermocouples are manufactured for a wide variety of applications. No one thermocouple will suit all applications. Thermocouples must be selected to meet the needs of a particular application.

The most basic thermocouple is the wire and bead type. The disadvantage of this type is that they all have an exposed junction. Although the exposed junction provides a good response time, it is open to the environment (oxidising and reducing atmospheres) leading to unstable temperature readings.

The Mineral Insulated Metal Sheathed (MIMS) thermocouple overcomes these disadvantages. The MIMS consists of two thermoelectric conductors embedded in highly compacted magnesium oxide insulation and protected by a metallic sheath.

MIMS

Advantages of MIMS Thermocouples:

Small in Diameter
Can be supplied in long lengths
Pliable for ease of installation
No additional Protection is required
Can withstand high pressure and thermal shock
Fast response time
High insulation resistance over a wide range of temperatures
Impervious to water, oil and gas
Thermoelectric conductors protected from oxidisation, environmental corrosion providing more stable temperature readings

Specifications:

EMF Standards and Tolerances

Mineral Insulated Thermocouples are manufactured with Nominal EMF / temperature characteristics complying with the new International Thermocouple Reference Tables which are published in the following standards:

BS 4937 (UK), ASTM E230-72 (USA), JISC 1602 (Japan).

MI Cable Sizes and Sheaths Available

Type	Outer Diameter (mm)	Sheath Material	Maximum Temperature
Type 'K' Single	1.0	310 SS	1100ºC
	1.5	310 SS	1100ºC
	1.5	Inconel 600 *1	1150ºC
	3.0	310 SS	1100ºC
	3.0	Inconel 600 *1	1150ºC
	3.0	Nicrobell *2	1200ºC
	4.5	310 SS	1100ºC
	4.5	Inconel 600 *1	1150ºC
	6.0	310 SS	1100ºC
	6.0	Inconel 600 *1	1150ºC
	6.0	Nicrobell *2	1200ºC
	5.5 Heavy Wall	310 SS	1100ºC
	5.5 Heavy Wall	Inconel 600 *1	1150ºC
	10.8 Heavy Wall	310 SS	1100ºC
	10.8 Heavy Wall	Inconel 600 *1	1150ºC
Type 'K' Duplex	3.0	310 SS	1100ºC
	4.5	310 SS	1100ºC
	6.0	310 SS	1100ºC
	6.0	Inconel 600 *1	1150ºC
Type 'J' Single	1.5	304 SS	750ºC
	3.0	310 SS	750ºC
	6.0	310 SS	750ºC
	6.0	321 SS	750ºC
Type 'J' Duplex	6.0	310 SS	750ºC
Type 'T' Single	1.5	Cupro-Nickel	400ºC
	3.0	321 SS	400ºC
	6.0	310 SS	400ºC
Type 'T' Duplex	6.0	310 SS	400ºC
Type 'N' Single	1.5	Nicrobell *2	1200ºC
	3.0	Nicrobell *2	1200ºC
	6.0	Nicrobell *2	1200ºC
Type 'N' Duplex	6.0	Nicrobell *2	1200ºC

*1 Inconel is a registered trade name of Henery Wiggin & Co Ltd.
*2 Nicrobell is a trademark of Nicrobell Pty Ltd.

Note: The above covers the more common Thermocouple probes. Other sizes and sheath materials available on request.