The PID insulation tester (TOS7210S) is designed based on the insulation resistance tester (TOS7200) to carry out the evaluation of the PID (Potential Induced Degradation) effect of the PV module precisely and efficiently.
Being equipped with the output ability of 2000 V and the ammeter with nA resolution as well as a polarity switching function, the TOS7210S is also applicable not only to the PID evaluation but also the evaluation of the insulators that requires a high sensitivity of measurement. The tester is equipped with the panel memory that is externally accessible and RS232C interface as standard; it can be flexibly compatible with the automated system.
The PID effect is a phenomenon that the amount of power generation by a cell remarkably decreases when high voltage is applied between the solar cell and the frame for long hours. It is supposed that the higher the applied voltage is and/or the higher and more humid the environment is, the further deterioration accelerates. For example, the potential difference in the string becomes extremely higher when the number of sheets that are connected in series increases even if the output voltage of the crystalline silicon solar cell module is just tens of volts.