TY - JOUR N2 - Testing of varistors using thermography was carried out in order to assess their protective properties against possible overvoltage phenomena in the form of high-level voltage surges. An advantage of the thermography technique is non-contact temperature measurement. It was proposed to assess the properties of varistors working in electronic devices as protective elements, on the basis of estimating temperature increments on varistor surfaces, registered by an infrared camera during surge resistance tests with standard voltage levels. To determine acceptable temperature increments on a tested varistor, preliminary testing was performed of P22Z1 (Littelfuse) and S07K14 (EPCOS) type varistors, working first at a constant load and presently during surge tests,. The thermographic test results were compared with measured varistor capacity values before and after tests. It was found that recording with thermography temperature increments greater than 6°C for both P22Z1 and S07K14 varistor types detects total or partial loss of varistor protective properties. The test results were confirmed by assessment of protective properties of varistors working in output circuits of low nominal voltage devices. L1 - http://www.czasopisma.pan.pl/Content/90206/PDF/Journal10178-VolumeXX%20Issue4_14.pdf L2 - http://www.czasopisma.pan.pl/Content/90206 PY - 2013 IS - No 4 EP - 688 DO - 10.2478/mms-2013-0058 KW - thermography KW - testing KW - varistors A1 - Galla, Stanisław A1 - Konczakowska, Alicja PB - Polish Academy of Sciences Committee on Metrology and Scientific Instrumentation DA - 2013 T1 - Application of Infrared Thermography to Non-Contact Testing of Varistors SP - 677 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/90206 T2 - Metrology and Measurement Systems ER -