The measurement principle of the surface charge analyzer is based on electrokinetic phenomena that occur near a charged surface in a polar solvent, such as water. The strength and type of surface charge (positive/negative) are very important properties for many surfaces. In membrane technology, for example, the operation of nanofiltration membranes is primarily based on surface charge. This analytical data is utilized in membrane research (such as fouling, cleaning during washing, and analyzing modifications to surface properties). The surface charge analyzer is one of the most essential tools for the membrane technology research.