Hioki 3541 - Page 177

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Appendix 2 Temperature Correction Function (TC)
Reference_____________________________________________________
Conductive Properties of Metals and Alloys
Copper Wire Conductivity
The temperature coefficient changes according to temperature and
conductivity, so if the temperature coefficient at 20°C is α
20
and the
temperature coefficient for conductivity C at t°C is α
ct
, α
ct
is
determined as follows near ambient temperature.
For example, the temperature coefficient of international standard
annealed copper is 3930 ppm @20°C. For tinned annealed copper
wire (with diameter from 0.10 to less than 0.26 mm), the temperature
coefficient
α
20
at 20°C is calculated as follows:
Material Content [%]
Density (x10
3
)
[ kg/m
3
]
Conductivity
Temp. Coeff.
(20°C) [ppm]
Annealed copper wire Cu>99.9 8.89 1.00 to 1.02 3810 to 3970
Hard-drawn copper
wire
Cu>99.9 8.89 0.96 to 0.98 3770 to 3850
Cadmium copper wire Cd 0.7 to 1.2 8.94 0.85 to 0.88 3340 to 3460
Silver copper Ag 0.03 to 0.1 8.89 0.96 to 0.98 3930
Chrome copper Cr 0.4 to 0.8 8.89
0.04 to 0.05
0.80 to 0.85
20
30
Carlson alloy wire
Ni 2.5 to 4.0
Si 0.5 to 1.0
0.25 to 0.45 980 to 1770
Annealed aluminum
wire
Al>99.5 2.7 0.63 to 0.64 42
Hard-drawn aluminum
wire
Al>99.5 2.7 0.60 to 0.62 40
Aldrey wire
Si 0.4 to 0.6
Mg 0.4 to 0.5
Al remaining
portion
0.50 to 0.55 36
Diameter [mm]
Annealed
copper wire
Tinned annealed
copper wire
Hard-drawn
copper wire
0.01 to less than 0.26 0.98 0.93 −
0.26 to less than 0.50 0.993 0.94 0.96
0.50 to less than 2.00 1.00 0.96 0.96
2.00 to less than 8.00 1.00 0.97 0.97
α
ct
1
1
α
20
C×
------------------ t 20–()+
-------------------------------------------=
α
20
1
1
0.00393 0.93×
------------------------------------2020–()+
-----------------------------------------------------------------=
≈ 3650 ppm