Mineral Insulated K Type Thermocouple With 2 Contacts Connector
SS304 Sheath Extension Cable Fast Response
For Mineral insulated (MI) thermocouples, the basic parts are
measuring element, insulation, protecting sheath. At most
situation, MI thermocouples matched with flexible connector to add
bending possibilities and compensation cables to improve the
measure accuracy.
Armor Style Thermocouple Structure
- For the measuring wire, there are several common used type: Type K
N E T J
2. Insulation Material: MgO(≥96%), Al2O3(≥99%)
3. Outer Sheath Material:
- 304L & 316L SS: + 700°C
- 310 (25/20) SS : + 1100°C
- Inconel 600 : + 1150°C
- GH3030 & GH3039: 1200°C
4. Mineral Insulated Parts Standards
Wire Diameter(D) And Tolerance | Sheath Thickness(S) Mini Value | Wire Diameter(C) Mini Value | Insulation Thickness(I) Mini Value |
| 0.5±0.025 | 0.05 | 0.08 | 0.04 |
| 1.0±0.025 | 0.10 | 0.15 | 0.08 |
| 1.5±0.025 | 0.15 | 0.23 | 0.12 |
| 2.0±0.025 | 0.20 | 0.30 | 0.16 |
| 3.0±0.030 | 0.30 | 0.45 | 0.24 |
| 4.5±0.045 | 0.45 | 0.68 | 0.36 |
| 6.0±0.060 | 0.60 | 0.90 | 0.48 |
| 8.0±0.080 | 0.80 | 1.20 | 0.64 |
5. Connector:usually this part made by spring to increase bending
possibilities.
6. Extension Cable:when chose the compensation/ Extension type, it
should in line with the thermocouple index
In actual temperature measurement, usually there are long measuring
distance with the measuring device, a thermocouple compensation
wire is generated to compensate the temperature difference caused
by the temperature change between the measuring device and the
thermocouple connecting piece.
The compensation cable has the following advantages: improving
thermocouple temperature measurement line physical properties and
mechanical properties; improving the measurement line flexibility
and making the connection convenient by using multi-strand core or
small-diameter compensation wire; easy to shield external
interference; reducing measuring lines cost.
Thermocouple Cable Grade
A:Extension Grade Cable
Whose wire composition is totally as the same as the thermocouple
wire, remarked by the letter“X”after the thermocouple symbol
number, such as“KX”“JX”“TX”
B:Compensation Grade Cable
Whose wire composition is different from the thermocouple wire, but
its wire electromotive force (EMF) value is the same as
thermocouple wire only at 0-100℃ or 0-200℃. It remarked by the
letter“C”after the thermocouple symbol number, such as“KC”“JC”“TC”
| Thermocouple Type | Alloy Code | Nominal Chemical Composition(%) | Recommend Measuring Temperature |
| Cu | Ni | Cr | Fe | Si | Al | Mn | Mg |
| Type K | KP(Chromel) | | 90 | 10 | | | | | | 0-1200℃ |
| KN(Alumel) | | 97 | | | 1-2 | 1-1.5 | 0.5-1.5 | |
| Type T | TP(Copper) | 100 | | | | | | | | -200-400℃ |
| TN(Constantan) | 55 | 45 | | | | | | |
| Type J | JP(Iron) | | | | 100 | | | | | 0~750℃ |
| JN(Constantan) | 55 | 45 | | | | | | |
| Type E | EP(Chromel) | | 90 | 10 | | | | | | 0~900℃ |
| EN(Constantan) | 55 | 45 | | | | | | |
| Type N | NP(NiCrSi) | | 83-85 | 13.7-14.7 | | 1.2-1.6 | | | <0.01 | 0-1200℃ |
| NN(NiSiMg) | | 93-96 | <0.02 | | 4.2-4.6 | | | 0.5-1.5 |
