This sensor uses a sodium ion selective electrode that is highly selective for sodium ions. Its working principle is based on the selective ion exchange and diffusion between the electrode membrane and the sodium ions in the solution to be tested, thereby generating a potential difference. By measuring this potential difference and according to the Nernst equation, the concentration of sodium ions in the solution can be determined. Nernst equation: The theoretical response value of the sodium ion selective electrode to a ten-fold change in ion concentration at 25℃ is 59.16mV, which is called the electrode slope (S). However, most electrodes do not show a theoretical slope, so the instrument needs to be calibrated to determine the true slope value of the electrode. In specific use, two standard solutions are used to calibrate the true slope value and zero point of the electrode.

Application fields: agricultural testing, environmental monitoring, industrial production, pulp and paper testing, steam engine power generation, and natural water monitoring.