Some science behind the scenes
Electrical conductivity of various materials
Electrical conductivity or specific conductance measures a material's ability to conduct an electric current. The table below shows the conductivity of various natural materials at 20 °C (68 °F). As you can see, anything that is metal is a good conductor. Pure water in contrast is not a good conductor, but the conductivity of a solution of water is highly dependent on its concentration of dissolved salts and other chemicals that ionise in the solution. Electrical conductivity of water samples is used as an indicator of how salt-free, ion-free, or impurity-free the sample is; the purer the water, the lower the conductivity (the higher the resistivity).
|
Material |
conductivity σ [siemens/metre] at 20 °C |
|
Silver |
6.30×107 |
|
Copper |
5.96×107 |
|
Gold |
4.52×107 |
|
Aluminium |
3.5×107 |
|
Calcium |
2.98×107 |
|
Tungsten |
1.79×107 |
|
Zinc |
1.69×107 |
|
Nickel |
1.43×107 |
|
Lithium |
1.08×107 |
|
Iron |
1.00×107 |
|
Platinum |
9.43×106 |
|
Tin |
9.17×106 |
|
Lead |
4.55×106 |
|
Titanium |
2.38×106 |
|
Manganin |
2.07×106 |
|
Constantan |
2.04×106 |
|
Mercury |
1.02×106 |
|
Nichrome |
9.09×105 |
|
Carbon (amorphous) |
1.25 to 2×103 |
|
Carbon (graphite) |
2 to 3×105 //basal plane |
|
Carbon (diamond) |
~10-13 |
|
Germanium |
2.17 |
|
Sea water |
4.8 |
|
Drinking water |
5×10-4 to 5×10-2 |
|
Silicon |
1.56×10-3 |
|
Sulfur |
10-16 |
|
Air |
3 to 8 × 10-15 |
|
Quartz (fused) |
1.3×10-18 |