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| Mineral Insulated Assemblies |
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In Mineral Insulated (MI) thermocouples, elements are surrounded by compact inorganic insulation (MgO) and housed in stainless
steel or heat resistant alloy sheath for protection from the environment. Compared to conventional beaded thermocouples, MI
thermocouples have the following advantages :
- Available in long lengths
- Can be bent, twisted and flattened at any point. Bends or distortions produce neither short circuits
nor ruptures at the sheath or cores. Long units can be wound into coils for easy transportation
- Smallest bending radius : 2 x sheath diameter
- Small sheath diameter and flexibility save installation space and create minimum flow obstruction
- High vibration strength since they contain no movable / brittle parts such as ceramic beads
- High insulation resistance and fast response
- Robust in construction and good mechanical strength
- Available in 1, 1.5, 2.5, 3, 4.5, 6, 8 and 10mm dia
- Available in J, K, T & N calibration
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| Standard Sheath Materials |
Sheath Material, Temperature Range |
| Circuit |
Cross
Section |
Sheath
dia In mm |
Available Sheath Materials |
| J |
K |
N |
T |
| Single |
 |
1.0 |
SS316 |
SS316, INCONEL 600 |
- |
- |
| 1.5 |
SS316 |
SS316, INCONEL 600 |
- |
SS316 |
| 3.0 |
SS316 |
SS316, INCONEL 600 |
INCONEL 600 |
SS316 |
| 4.5 |
SS316 |
SS316, INCONEL 600 |
- |
- |
| 6.0 |
SS316 |
SS316,SS 310 SS446,INCONEL 600 |
INCONEL 600 |
SS316 |
| 8.0 |
SS316 |
SS316,SS 310 ,INCONEL 600 |
INCONEL 600 |
- |
| 10.0 |
- |
SS 310 ,INCONEL 600 |
- |
- |
| Dual |
 |
3.0 |
SS316 |
SS316, INCONEL 600 |
- |
- |
| 4.5 |
SS316 |
SS316, INCONEL 600 |
- |
- |
| 6.0 |
SS316 |
SS316, SS310, INCONEL 600 |
- |
- |
| 8.0 |
SS316 |
SS316, SS310, INCONEL 600 |
- |
- |
| 10.0 |
- |
INCONEL 600 |
- |
- |
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| Calibration |
Sheath Material |
Temperature Range |
| Iron / Constantan (J) |
SS316 |
0 to 600°C |
| Chromel / Alumel (K) |
SS316* |
0 to 850°C |
| Chromel / Alumel (K) |
SS310** |
0 to1000°C |
| Chromel / Alumel(K) |
SS446*** |
0 to 1100°C |
| Chromel / Alumel(K) |
INCONEL 600 |
0 to 1150°C |
| Copper / Constantan(T) |
SS316 |
-200 to 350°C |
| Nicrosil / Nisil (N) |
INCONEL 600 |
0 to 1150°C |
* Available in 6 & 8mm diameters only
** Available in 6mm dia only. No nickel content. Best suitable for sulphur bearing atmosphere |
Minimum wall thickness : 10% of OD
Minimum element dia : 15% of OD
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