TY - JOUR N2 - Varistors are commonly used elements which protect power supply networks against high-voltage surges or lightning. Therefore, quality and endurance of these elements is important to avoid losses when an expensive laboratory equipment would not be protected from random overvoltages. Additionally, excessive leakage currents generate serious costs due to high energy consumption. The paper presents shortly properties of varistors that comprized different ZnO grain types and can have various quality which changes continuously during exploitation (due to exposition to overheating and overvoltage pulses). Therefore, it is important to monitor varistors during their ageing (causing changes within their microstructures). A few methods of varistor property diagnosis were considered and compared with the methods currently applied in laboratory or industry applications. A new measurement (diagnostic) system that can monitor varistors during ageing and can be widely applied in power networks is presented. The proposed system fulfills requirements of the industrial customers which demand various methods for power line protection. The proposed system can be simply developed into a more advanced wireless diagnostic system of long power supply lines. L1 - http://journals.pan.pl/Content/89935/PDF/Journal10178-VolumeXIX%20Issue2_19paper.pdf L2 - http://journals.pan.pl/Content/89935 PY - 2012 IS - No 2 EP - 404 DO - 10.2478/v10178-012-0034-7 KW - varistors KW - quality KW - ageing A1 - Smulko, Janusz A1 - Olesz, Marek A1 - Hasse, Lech A1 - Kaczmarek, Leszek A1 - Lentka, Grzegorz PB - Polish Academy of Sciences Committee on Metrology and Scientific Instrumentation DA - 2012 T1 - Problems of Varistor Quality Assessment During Exploitation SP - 395 UR - http://journals.pan.pl/dlibra/publication/edition/89935 T2 - Metrology and Measurement Systems ER -