The dielectric loss tester (also known as the dissipation factor tester) is a professional instrument used to evaluate the insulation performance of high-voltage electrical equipment



It sensitively determines whether the insulation is damp, aged, or has other defects by measuring the dielectric loss factor (tanδ) and capacitance (Cx) of the equipment.

⚙️ Working Principle

When an AC voltage is applied to a dielectric (insulating material), part of the electrical energy is converted into heat and lost, which is called dielectric loss. The dielectric loss factor tanδ is a key parameter that measures the magnitude of this energy loss. The larger the tanδ value, the greater the loss of the insulating material and the poorer its performance.

The basic principle of the tester is to construct a measuring bridge (such as a digital variant of the Schering bridge), which internally contains a highly stable standard capacitor (Cn) and the device under test (Cx). The instrument applies a stable high voltage to both, and by precisely measuring the amplitude and phase difference of the currents in the two circuits, it calculates the tanδ and Cx values of the device under test through vector operations performed by the internal microprocessor.