Cuprothal®

Thermocouple stripDatasheet

Datasheet updated 2024-09-05 11:41 (supersedes all previous editions)

Disclaimer: Recommendations are for guidance only, and the suitability of a material for a specific application can be confirmed only when we know the actual service conditions. Continuous development may necessitate changes in technical data without notice. This datasheet is only valid for materials under the trademark Kanthal^®.

Cuprothal® thermocouple strip is an austenitic copper-nickel alloy (CuNi alloy) with low specific resistance. It is used for the negative conductor of the following types of thermocouples and compensation cables: E, J, T, and KCB (VX). Cuprothal® can be used at temperatures down to 20 K, where the Seebeck coefficient is approximately 8 μV/K.

Thermocouple Type E has the highest electromotive force among common thermocouples, and for this reason, it is used in thermoelectric generators (thermopiles).

Cuprothal® Type T is used in combination with electrolytic copper (ASTM standard B3). Thermocouple Type T is used in both laboratory and industrial applications.

Cuprothal® Type KNCB (VNX) is used in combination with electrolytic copper when used as a compensating wire for Thermocouple Type K.

Chemical composition

	Ni %	Mn %	Fe %	Co %	Cu %
Nominal composition	44.0	0.5	0.5	0.3	Bal.

Mechanical properties

Wire size	Yield strength	Tensile strength	Elongation	Hardness
Ø	R_p0.2	R_m	A
mm	MPa	MPa	%	Hv
1.50	250	480	30	100-130

Physical properties

Density g/cm³	8.9
Electrical resistivity at 20°C Ω mm²/m	0.49

Temperature factor of resistivity
Temperature °C	100	200	300	400	500	600
Ct	1.002	1.002	1.001	1.005	1.017	1.037

Coefficient of thermal expansion
Temperature °C	Thermal Expansion x 10^-6/K
20 - 100	14

Thermal conductivity
Temperature °C	20
W m^-1 K^-1	21

Specific heat capacity
Temperature °C	20
kJ kg^-1 K^-1	0.410

Melting point °C	1280
Magnetic properties	The material is non-magnetic

Thermoelectric properties

CUPROTHAL™JNX

Nominal emf values vs Iron
Temperature °C	100	200
mV	5.269	10.779

ITS 90 - Reference junction 0°C

CUPROTHAL^®TNX

Nominal emf values vs electrolytic copper (ASTM B3)
Temperature °C	100	200
mV	4.279	9.288

ITS 90 - Reference junction 0°C

CUPROTHAL^®ENX

Nominal emf values vs Thermothal P (KP)
Temperature °C	100	200
mV	6.319	13.421

ITS 90 - Reference junction 0°C

CUPROTHAL^®KNCB (VNX)

Nominal emf values vs electrolytic copper (ASTM B3)
Temperature °C	100
mV	4.096

ITS 90 - Reference junction 0°C

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Cuprothal®

Chemical composition

Mechanical properties

Physical properties

Thermoelectric properties

CUPROTHAL™JNX

CUPROTHAL®TNX

CUPROTHAL®ENX

CUPROTHAL®KNCB (VNX)

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CUPROTHAL^®TNX

CUPROTHAL^®ENX

CUPROTHAL^®KNCB (VNX)