该方法基于当氟离子选择电极与含有氟离子的水溶液接触时，在测量电极和参比电极之间产生电位差。在规定的某些假设条件下，该方法将不再参考放射性，而是参考氟离子浓度。该方法直接适用于测量0.2 mg/l至2.0 g/l的氟化物浓度。

The method is based on developing a potential difference between the measuring electrode and the reference electrode, when a fluoride ion-selective electrode comes into contact with an aqueous solution containing fluoride ions. On certain assumptions specified, the method will no longer refer to activities, but to fluoride ion concentration. The method is directly suitable for measuring fluoride concentrations from 0,2 mg/l to 2,0 g/l.