Mineral Insulated Thermocouples

 Wide choice of Sheaths, Cold and Hot Ends and Conductor Types

 Approval to Power Station Standards

 Standard and Customised Designs

 Special Tolerances to order

General Description

Our mineral insulated thermocouples are manufactured from superior grade materials.  We provide technical expertise, advice, design and a manufacturing facility second to none.

Thermocouple Types

Type Conductor Materials Standard Tolerances (cl2)
K Nickel-Chromium /Nickel-Aluminium

40C to 333C            :         2.5C
333C to 1200C       :          0.75%

J  Iron/ Copper-Nickel

-40C to 333C          :           2.5C
333C to 750C          :          0.75%

T Copper/Copper-Nickel

-40C to 133C          :           1C
133C to 350C          :           0.75%

E Nickel-Chromium/ Copper-Nickel

-40C to 333C          :          2.5C
333C to 900C          :         0.75%

N Nickel-Chromium/ Nickel-Silicon

40C to 333C            :         2.5C
333C to 1200C        :        0.75%

B Platinum-30%Rhodium/ 
Platinum-6%Rhodium

0 to 600C                   :        1.5C
600C to 1700C        :        0.25%

R Platinum-13% Rhodium/ Platinum

0 to 600C                   :        1.5C
600C to 1600C        :        0.25%

S Platinum-10% Rhodium/ Platinum

0 to 600C                   :        1.5C
600C to 1600C        :        0.25%

Class 1 tolerances available to order

Applicable Standards

EMF VALUES:-

 IEC 60854:1195, ANSI mc 96.01
Tables of EMF values are available from Jagjan. Refer to Technical Data Sheets JAG/TYPK, JAG/TYPJ, JAG/TYPT, JAG/TYPE, JAG/TYPN, JAG/TYPB, JAG/TYPR and JAG/TYPS

Colour Codes:- IEC 584-3:1989
A thermocouple colour code chart is available from Jagjan. Refer to Technical Data Sheet JAG/TCC

Tolerances:-   IEC 60584-2:1982, ANSI MC 96.01

Hot End Junctions:-

Insulated Junction:- 

Insulated hot end junctions are suitable for most applications, especially where low EMF pick-up is essential. High insulation resistance is enhanced due to extreme compaction of the high purity MgO powder insulation.

Grounded Junction

Bonded or grounded junctions offer a slightly faster temperature response than the insulated junction type. Not recommended for multi-point instrumentation.

Exposed Junction :-

Bare or exposed junction thermocouples provide extremely fast temperature response. Although the exposed MgO is completely moisture sealed, it is not recommended for corrosive environments or temperatures in excess of 300C.

Extended Tip Junction :-

 

Extended tip junctions can also be provided to special order. Their solid end makes this type of construction ideal for spot welding or peening to the contact surface. The standard version has a pointed tip 15 mm long. Other shapes can be provided.

Reduced Tip Junction :-

 

Reduced tip junctions are ideal for applications where low mass and extremely fast response times are required, together with good mechanical strength. 

Sheaths and Conductors :-

A wide range of standard sheath materials are available, including 310, 304, 316, 321 Stainless Steel,  Inconel 600, Incolloy 800 and Cupro/Nickel. Thermocouple types J,T,K,E and N can be supplied as standard, in simplex, duplex, and in most cases triplex configurations

Special Sheaths :-

Special sheaths are available including AISI 446 Stainless Steel, 347 Stainless Steel, Nicrosil, Hastelloy etc. 

Special Conductors :-

A wide range of special conductors are available including Platinum-Rhodium/Platinum, Platinel and Tungsten/Rhenium.

Special Coatings :-

A wide variety of fluoroplastic coatings can be provided to meet corrosive environments. Standard coatings include PPS, PVDF or PFA. Fluoroshield, a fluorocarbon polymer, can also be provided.

The table below shows the sheath/conductor combinations which are the most common, and are  available at short notice from Jagjan  

Type K- Nickel chromium/Nickel Aluminium
Sheath material Outside Diameter (mm)
8.0 6.0 4.5 3.0 1.5
310 Stainless Steel
Inconel 600
316 Stainless Steel
Type J- Iron/Copper-Nickel 
Sheath material

Outside Diameter (mm)

8.0 6.0 4.5 3.0 1.5
316 Stainless Steel
Type T- Copper/Copper-Nickel 
Sheath material

Outside Diameter (mm)

8.0 6.0 4.5 3.0 1.5
316 Stainless Steel
Type E- Nickel-Chromium/Copper-Nickel 
Sheath material

Outside Diameter (mm)

8.0 6.0 4.5 3.0 1.5
316 Stainless Steel
Type N- Nickel-Chromium/Nickel -Silicon
Sheath material

Outside Diameter (mm)

8.0 6.0 4.5 3.0 1.5
Inconel 600

                                                   = Simplex
                                                                                                                                                                    = Duplex

Fittings :-

A wide range of termination glands and adjustable compression fittings are available to suit thermocouples of all diameters.

Sliding Compression Fitting

Transmitter Baseplates :- 

 

Thermocouples can be manufactured with DIN mounting plates to suit temperature transmitters. 

Moulded Plugs :-

 

The heavy duty plug is a standard round 2 pin moulded plug suitable for 1.0 mm, 1.5 mm, 2.0 mm, 3.0 mm, 4.5 mm and6.0 mm diameter thermocouples. Maximum ambient temperature is 270oC. A duplex version is also available .

The smaller plug is a miniature flat 2 pin moulded plug which can be fitted to 1.0 mm, 1.5 mm, 2.0 mm and 3.0 mm diameter thermocouples. 

Both heavy duty and smaller can be supplied in socket end versions. An alternative range of high temperature plug and socket combinations is available with ceramic bodies.

Standard Seals :-

 

A Wide variety of standard and custom designed seals can be manufactured to suit specific applications.

The C Pot is a stainless steel crimped - on epoxy resin seal, suitable for 1.5  mm, 3.0 mm, 4.5 mm,  6.0 mm and 8.0 mm dianeter thermocouples.

Maximum ambient temperature is 85oC when fitted with PVC tail wires and 180oC when fitted with PTFE tail wires and high temperature epoxy. 

Threaded Seals :-

The A Pot is an M8 threaded epox.y resin seal for  1.5 mm,  3.0 mm and 4.5 mm thermocouples.

The B Pot is an M10 threaded epoxy resin seal for 3.0 mm, 4.5 mm,  6.0 mm or 8.0 mm thermocouples. Locknuts can be supplied. Maximum ambient temperature is 85oC when fitted with PVC tail wires and 180oC when fitted with PTFE tail wires and high temperature epoxy.

Thermocouple Material Selection Chart:-

T/C
Type

Sheath Material

Maximum Operating Temperature

Some Typical Applications

Remarks

K 310 Stainless Steel

1100oC

Blast Furnace Gases, Open Hearth Furnace Flues, Re-Heat and Annealing Furnaces, Brick Kilns, Power Station Boilers, High Temperature Superheater Tubes, Vitreous enamelling.

Good oxidation resistance properties but should not be subjected to subsequent mainpulation. Satisfacotry in sulphur-bearing atmospheres.

K Inconel 600

1100oC

Heat Treatment Processes, Chemical Reactors, Annealing Furnaces- Trailing Thermocouples, Soaking Pits, Glass Tank Flues, Cement Kilns, Incinerators and Aircraft Engines.

Excellent high temperature strength and resistance to oxidation but should not be used in sulphur-bearing atmospheres above 550oC. Very good chemcal resistance, almost immune to chloride- ion stress cracking

K 321 Stainless Steel

800oC

Nuclear Energy 'In-Pile' Instrumentation, Annealing Furnaces, Chemical Acid Production (Acetic, Nitric etc.), Boiler Steam and feed water, Turbo -Alternator Steam Measurement, Heat Exchangers. Food and Beverage Processing.

Excellent resistance to corrosion in a wide range of industrial applications, retaining good ductility properties. This grade is titanium stabilized for improved welding characteristics.

K 316 Stainless Steel 900oC

Applications as 321SS, but with improved resistance to a wide range of more aggressive chemicals. Widely used in paper Digesters.

Best corrosion resistance of the austenitic stainless steels, widely used in chemical processing, offers useful resistance to H2S, dry chlorine gas and sodium chloride.

E 321 Stainless Steel 800oC

Annealing Furnaces, Chemical Acid Production (Acetic, Nitric etc), high EMF output ideal for low temperature sensitivity.

Excellent resistance to corrosion in a wide range of industrial applications, retaining good ductility properties. This grade is titanium stabilized for improved welding characteristics

J Inconel 600 800oC

Polyehylene Manufacture, Tar Stills, Paper Manufacturing Plant.

Excellent oxidation resistance, but should not be used in sulphur -bearing atmospheres at temperatures above 550oC. Very good chemical resistance, almost immune to chloride-ion stress cracking.

J 321 Stainless Steel 750oC

Re- heat and Annealing Fumaces aluminium Heat Treatment, Chemical Reactors, Plastic injection Moulding Machines.

Excellent resistance to corrosion in a wide range of industrial applications, retaining good ductility properties. This grade is titanium stabilized for improved welding characteristics.

T 321 Stainless Steel 400oC

Producer Gas Plant, Oil Lubricant Temperature Measurement, widely used in Cryogenic applications. Type T thermocouples are more accurate than other base metal types.

Excellent resistance to corrosion in a wide range of industrial applications, retaining good ductility properties. This grade is titanium stabilized for improved welding characteristics.

- Nicrobell 1300oC

Blast Furnace Gases, Heat Treatment, Brick Kilns, Power Station Boilers, Nuclear 'In-Pile' instrumentation, Semiconductor Manufacturing.

Lowest drift of the base metal thermocouple group, particularly good at extreme temperatures and nuclear applications. Can replace expensive platinum types in some applications.