A brief short circuit is not sufficient to relax the entire spectrum of the stress accumulated in an insulator during a long time polarization. Following neutralization, a return voltage appears. This phenomenon is used as a routine characterization tool in some areas of electrical engineering. Several experimental results are detailed here supporting the interest of this electrostatic technique as a laboratory characterization tool. For instance, the sensitivity of this technique may be applied to follow the ageing of cables for the aircraft industry, as well as to monitor interfacial polarization build-up at high temperature on polarized alumina plates. It has also been used to demonstrate a photoelectret effect on polyimide films, which is described.

We analyze here the diverse physical processes that may be responsible for return voltage: slow dipolar relaxation processes, interfacial polarization, heterogeneous conductivity and injected space charge motion.

短暂的短路不足以放松长时间极化期间绝缘体中积累的整个应力谱。中和后，出现返回电压。这种现象在电气工程的某些领域被用作常规表征工具。这里详细介绍了几个实验结果，支持这种静电技术作为实验室表征工具的兴趣。例如，该技术的灵敏度可用于跟踪航空工业电缆的老化情况，以及监测在高温下极化氧化铝板上的界面极化累积。它还被用于证明对聚酰亚胺薄膜的光电驻极体效应，对此进行了描述。

我们在这里分析可能导致返回电压的各种物理过程：慢偶极弛豫过程、界面极化、异质电导率和注入的空间电荷运动。