WD6000A Different Frequency Automatic Dielectric is a high-precision instrument, which can be applied to automatically measure electrical loss tangent () and capacitance of all kinds of high voltage electrical equipments on the spot of power plants, substations, laboratory, etc. The instrument is an integrated structure with a dielectric loss test bridge, a variable frequency power supply, a step-up transformer and a SF6 high stability standard capacitor. High voltage source inverter test generated inside the instrument, the transformer voltage for sample test. If the frequency is 50Hz, 47.5Hz*.5Hz, 45Hz-Hz, 60Hz, 57.5Hz2.5Hz, 55Hz5Hz, the digital notch filter is used to avoid the interference of the power frequency electric field to the test, which solves the problem of accurate measurement under the strong electric field interference. At the same time, the utility model is suitable for the occasions that the generator is used for power supply after the power cut. The instrument wit h insulation cup can test the dielectric loss of insulating oil.