T.O. 33B-1-1
4-77
4.7.1.24
Measurement Of Conductivity.
Absolute values of conductivity are usually determined by measuring the resistivity of a metal under very closely
controlled laboratory conditions. Conductivity is calculated as the reciprocal of resistivity as follows:
C=1/R
Where:
C
=
Conductivity mhos/inch
R
=
Resistivity ohm.inch
Conductivity can be converted to % IACS units as described in section 4.2.2.1.1.3
4.7.1.25
Field Measurement Of Conductivity.
For determination of electrical conductivity under production and field conditions, eddy current instrumentation is
employed. The eddy current instruments are calibrated against standards of known conductivity. When available,
instruments designed specifically for measurement of conductivity are used. These instruments measure conductivity
directly in % IACS.
Table 4-7. Electrical Conductivity Ranges for Aluminum Alloys
Electrical Conductivity
(%IACS)
Alloy and Temper
Minimum
Maximum
1100 (All tempers)
57.0
62.0
2041-0
48-5
51.5
2013-T3XX
31.5
35.0
2041-T4XX
31.5
35.0
2013-T6XX
37.0
41.5
2024-0
45.5
50.0
2024-T3XX
28.0
33.0
2024-T4XX
28.5
32.5
2024-T6XX
35.0
41.0
2024-T8XX
36.00
42.5
2219-0
43.0
46.0
2219T3XX
27.0
31.0
2219-T62X
31.0
35.5
2219-T8XX
31.0
35.5
3003-0
44.5
50.0
6061-0
47.0
51.0
6061-T4XX
35.5
41.5
6061-T6XX
40.0
45.0
7075-0
44.0
48.0
7075-T6XX
30.0
35.0
7075-T73X
38.0
42.5
7075-T76X
36.0
39.0
7079-0
44.0
47.0
7079-T6XX
30.0
35.0
7079-T6XX
30.0
35.0
7178-0
43.0
47.0
7178-T6XX
29.0
34.0
7178-T76
35.0
39.0
