Determination of changes in NaCl concentration in aqueous solutions using an M-sequence based sensor system

In this paper measurements of changes in NaCl concentration in aqueous solutions are presented. For these measurements a simplified pseudo random binary sequence (PRBS) based sensor system, which is based on the binary noise theorem, is used. The pseudo random noise signal is represented by an M-sequence with a bandwidth of 10GHz. The transfer functions of the sensor with different NaCl concentrations in a fixed tube of a contactless distributed probe are determined and compared to each other. The results show that there is a frequency range with a clear relation between the magnitude of the transfer function and the NaCl concentration. This demonstrates, that it is possible to measure changes in NaCl concentration of aqueous solutions with a PRBS based sensor system.