for conductivity measurement
Conductivity is a parameter used to measure electrical properties of a solution. The more salt, acid or alkali in a solution, the greater its conductivity. The unit of conductivity is S/m, often also S/cm.
Conductivity measurements are used for applications such as in the production of ultrapure water or determining the salinity of saltwater.
Conductivity is measured by making a measurement of the electrical resistance. The simplest kind of measuring cell used consists of two similar electrodes. An alternating voltage applied to one of the electrodes causes the ions in the solution to migrate towards the electrodes. The more ions in the solution, the greater the current which flows between the electrodes. The instrument measures the current and uses Ohm’s law to calculate first the conductance of the solution and then – by taking the cell data into account – the conductivity.