Electric Conductivity Conversion Hub

Understanding Electrical Conductivity & Carrier Mobility

Electrical conductivity (symbolized by $\sigma$ or $\kappa$) is an intrinsic material property representing the reciprocal of electrical resistivity ($\sigma = \frac{1}{\rho}$). It measures a substance's ability to conduct electrical current, governed microscopically by free charge carrier density ($n$) and carrier mobility ($\mu_e$): $\sigma = n q \mu_e$.

Key Units & International Standards

• SI Metric: Siemens per meter ($\text{S}/\text{m}$) or microsiemens per centimeter ($\mu\text{S}/\text{cm}$).
• IACS Standard: Percentage of the International Annealed Copper Standard (% IACS). Pure annealed copper is standardized at $100\%\text{ IACS} = 5.80 \times 10^7\text{ S}/\text{m}$. Pure silver achieves $\approx 106\%\text{ IACS}$.
• Water Quality Scales: $\mu\text{S}/\text{cm}$ or $\text{mS}/\text{m}$. Pure deionized water has $\sigma < 0.05\ \mu\text{S}/\text{cm}$, while seawater measures $\approx 50,000\ \mu\text{S}/\text{cm}$.

Engineering Applications

Used to verify heat-treatment temper in aerospace aluminum alloys via eddy current testing, monitor reverse osmosis water purification purity, and select conductive silver pastes for solar cell metallization.