Fe-CuNi(Constantan) thermocouple wire(Type-J)

Fe-CuNi thermocouple (type J) is also named Fe- Constantan thermocouple. The positive leg made by pure lron, and the main chemical composition of negative leg Constantan (JN) is Cu: Ni≈ 55%: 45%. Although they are all called Constantan, JN does not give the same EMF output curve as EN and TN, it ca

DETAIL

Fe-CuNi thermocouple (type J) is also named Fe- Constantan thermocouple. The positive leg made by pure lron, and the main chemical composition of negative leg Constantan (JN) is Cu: Ni≈ 55%: 45%. Although they are all called Constantan, JN does not give the same EMF output curve as EN and TN, it cannot be instead by other Constantan.


The operating temperature range of type J thermocouple is-210~1200℃, but it is usually used in the temperature range 0-750℃due to embrittlement of Iron.

 

TYPE AND MAIN CHEMICAL POMPOSITION(%)


Type

Chemical composition(%)

NI

Cu

Mn

Si

Fe

Fe JP

/

/

/

/

100

CuNi JN

45

55

/

/

/

Standard

IEC60584-1

Type

EMF Versus Pt.67 (mV)

100℃

200℃

300℃

400℃

600℃

JP-JN

5.207-5.331

10.717-10.841

16.244-16.410

21.760-21.936

32.956-33.236

Physical property

Type

Density(g/c㎡) at 20℃

Melting point(℃)

Tensile Strength (Soft annealed condition in 20℃)

Elongation% (Soft annealed condition in 20℃)

Resistivity at 20℃(μΩ·m)

JP

7.8

1407

≥240

≥20

0.12

JN

8.9

1220

≥390

≥25

0.49