Abstract: The line resistance is the key factor for precise measurement in the dual high precision programmable voltage supply （DVS）. The two sets of data were got by measurement under the condition of two different line resistances. The validating with statistics of the two sets of data was done, and the result of the DVS output voltage, which is independent of line resistance, was proved. It means the DVS circuit omits the affection of line resistance. The statistics method is valued for testing the physical parameters in system. 

Key words: laser, resistance, measurement, statistics