DB13/T 5255-2020 "Determination of square resistance of graphene electric conductive ink, four probe method" This standard specifies the measurement method of square resistance of graphene electric conductive ink, which is suitable for the detection of square resistance of graphene electric conductive ink and Miscellaneous carbon material electric conductive ink. The standard uses the four probe method for measurement, and the square resistance value is calculated by applying a current and a measurement voltage to the surface of the thin film sample. The test conditions include temperature (1535 ° C), relative humidity (45% 75%) and atmospheric pressure (86106 kPa). The test steps include sample preparation, film thickness measurement and square resistance test. The final result is expressed in the form of "what is the square resistance value at a certain thickness". This standard provides a scientific basis for the quality control and performance evaluation of graphene electric conductive inks.