In this paper

the structural principle of capacitor voltage transformer（CVT）withou t intermediate tap is simply introduced

the capacitance and dielectric loss measurement on the upper and lower section capacitor cells are discussed;the self-excitation measurement method and error are briefly analyzed item by item and the specific preventive measures are proposed.It is known by the analysis that the onsite measurement error in which the dielectric loss is creased due to insulation drop of "δ"terminal（or the secondary winding）and bad contact of intermediate flange shall be especially eliminated and

at the same time

such error factors as leakage current

bridge lead and electric field interference shall also be prevented and controlled at site.