Handling faults, not the analyser, produce most misleading DGA results. The gas signatures that identify air ingress, degassing loss and contamination, and the order to rule them out.
Partial discharge monitoring cost is driven less by sensors than by channel count, outage timing and integration. How to compare two quotes honestly.
Online DGA monitor brands share a product category, not a measurement. Compare them by principle, gas coverage, consumables and retrofit fit before you quote.
Partial discharge detection methods compared by physics, not marketing: what UHF, HFCT, AE and RF each sense, where they mount, and what each one cannot hear.
Transformer fault diagnosis means choosing a method whose failure edge you know. Ratios, the Duval triangle and ML classifiers each stop answering somewhere.
Online vs offline partial discharge testing is not a sensitivity contest. One is pC-calibrated and brief, the other relative and continuous, and they answer different questions.
IEC 60422 sets transformer oil test frequency by equipment category and risk. Its scope also excludes dissolved gas analysis, which is where a schedule stops being enough.
Bushing partial discharge monitoring begins at the flange tap. The condenser core is a coupling capacitor, and the tap is the port it was always meant to be read from.
The transformer oil sampling procedure is the first measurement in dissolved gas analysis. Flushing, container and transport decide what the lab can still see.
Partial discharge source location turns a detected pulse into a position. Why it needs nanosecond timing and multiple UHF sensors, and where it fails.
