Mathematical Relationship Between Hotspot Temperature, Emissivity and Distance in Thermographs for Condition Monitoring of Electrical Equipments

Abstract

Heat is an effective indicator for condition monitoring of electrical equipments. Heat is measured using thermal camera, which maps heat patterns into thermographs. Hotspot or coldspot indicates an anomaly. Periodic recording and analysis of thermographs indicate the health of these electrical equipments. However hotspot/coldspot temperature is also dependent on emissivity and distance at which thermographs are acquired. Hotspots are extracted using thresholding based image segmentation. Hence the proposed work aims at deriving a relationship between hotspot temperature, emissivity and distance. Both one dimensional and two dimensional relationships relating the above three parameters are obtained. Hence the actual temperature can be obtained using these equations from thermographs.