The voltage breakdown tester is the core equipment for evaluating the insulation performance of materials, and its testing principle is based on the dynamic game between electric field strength and dielectric strength. When the electric field strength exceeds the critical value of the material, the insulating medium will undergo irreversible breakdown discharge, which reveals the electrical limit of the material under certain conditions.
Test principle: Ladder boosting and transient capture
The tester applies a stepped up electric field to the sample through a high-voltage generator, and the boosting rate can be precisely adjusted to simulate different working conditions. For example, in power equipment testing, the boost rate may be set to several hundred volts per second to simulate overvoltage surges; In material research, a slow boost of several volts per second may be used to observe the effect of thermal effects on breakdown. When the electric field strength reaches a critical value, a conductive channel is formed inside the medium, and the sudden increase in current causes a voltage drop. The instrument captures this transient change within 0.1 seconds through high-precision sensors and automatically cuts off the power supply to protect the sample. During this process, the instrument synchronously records the breakdown voltage, current waveform, and time parameters, providing data support for subsequent analysis.
Breakdown mechanism: the result of the synergistic effect of multiple factors
The essence of breakdown phenomenon is the critical point at which the electric field energy breaks through the confinement of the medium. In solid media, electrons accelerate and collide with lattice atoms under strong electric fields, causing electron avalanche and damaging the lattice structure, resulting in a sudden increase in conductivity; Liquid media may form bubbles due to local ionization, leading to chain discharge; When the electric field strength in a gas medium exceeds the ionization energy level of the gas, an arc discharge channel will be formed. In addition, factors such as temperature, humidity, and impurities significantly affect the breakdown characteristics: high temperatures intensify molecular thermal motion and reduce breakdown voltage; A humid environment may introduce conductive ions, leading to partial discharge; Impurities or micro pores can lead to electric field concentration, causing local breakdown.
Application value: Security protection from laboratory to production line
The voltage breakdown tester provides key performance data for power equipment, electronic components, and aerospace materials. In the design of high-voltage transmission lines, the insulation distance and material selection can be optimized by testing the breakdown voltage of insulators; In the field of new energy vehicles, the withstand voltage test of battery casings ensures that they can withstand high voltages above 300V without being broken down; In semiconductor manufacturing, the reliability of wafer insulation layers is evaluated through pulse voltage testing. This device eliminates safety hazards from the source by quantifying the ultimate withstand voltage capability of materials, becoming a "safety guardian" for electrical safety testing and material science research.