The fault free operation of power #transformers is a factor of major economic importance and safety in power supply utilities and industrial consumers of electricity.
In the current economic climate, Industries/Supply Utilities tighten their control on capital spending and make cutbacks in #maintenance, an increased awareness is placed on the #reliability of the existing electric power supply. Down time is at a premium. Often, the loading is increase on present units , as this will defer purchasing additional plant capacity. Thus the stress on the transformer increases. The net total effect of the thermal , electrical and mechanical stress brought on by increased service needs to be monitored to ensure #electricalreliability.
I have attached a great guide in PDF below.
A GUIDE TO TRANSFORMER OIL ANALYSIS BY I.A.R. GRAY Transformer Chemistry Services