Atomika Conductivity Standards are made to order and meet our exacting quality standards. Conductivity or specific conductance of a solution is a measure of its ability to conduct electricity. The SI unit of conductivity is siemens per meter (S/m), and unless otherwise qualified, it refers to 25 °C. More generally encountered is the traditional unit of μS/cm. Conductivity measurements are used routinely in many industrial and environmental applications as a fast, inexpensive and reliable way of measuring the ionic content in a solution. For example, the measurement of product conductivity is a typical way to monitor and continuously trend the performance of water purification systems. In many cases, conductivity is linked directly to the total dissolved solids (TDS).