HB/Z 5110.2-2000 "Electrochemistry deoiling and chemical deoiling solution analysis method, potential Titrimetric method for the determination of sodiumhydrate, sodium carbonate, phosphoric acid trisodium content" standard stipulates the use of potential Titrimetric method for the determination of electrochemistry deoiling and chemical deoiling solution sodiumhydrate, sodium carbonate (Na2CO3 · 10H2O), phosphoric acid trisodium (Na3PO4 · 12H2O) content of the method principle, reagents, instruments, analysis steps and calculation results. It is suitable for the determination of the above chemical substances in electrochemistry degreasing and chemical degreasing solutions. Measurement range is: sodiumhydrate 5~ 55g/L; sodium carbonate 15~ 35g/L; phosphoric acid trisodium 15~ 65g/L. The method is based on acid-base neutralization reaction, using Glass electrode and saturated Calomel electrode for Potentiometric titration, poten-tiometry, and titration endpoints are determined at different pH values according to the dissociation series of different chemicals.