Earth fault factor and the arrester TOV curve, why 0.1 Hz cuts source power by 600, the cycle-count trap below 0.1 Hz, and the full four-hour field campaign.

From loss of hydrophobicity to the carbon track: dry band arcing, the inclined plane test, salt fog at component level, and how to write climatic requirements.

Why a transformer can pass every dielectric test and still carry a silent deformation, and how the frequency signature exposes it when the comparison is valid.

Loss physics, the Schering bridge and its digital successor, choosing the measurement mode, individual temperature correction, and eight cases where the number lies.

Where the quantity came from, how the quasi-peak detector weights repetition rate, which standards still require RIV, and how to read a combined RIV and PD campaign.

Cavity, corona, surface and floating electrode physics; the circuit and its calibration; per-family limits; PRPD reading; and the non-conventional methods.