Datasheet specs are the entry ticket; 15-year total cost of ownership and long-term reliability are what decide. On that count, even CIGRE pours cold water: online DGA device life is typically only a quarter of the transformer’s.
Datasheets are written to be compared badly. A weighted nine-dimension scorecard turns an online DGA monitor selection into a decision you can defend in a tender file.
A fifty-transformer campaign is where the complaint \”PD testing system not portable\” turns into a schedule problem. Four field constraints decide what you can actually buy.
A handheld survey and a permanent transformer PD monitoring system answer different questions. Here are the four specifications that decide which one you are actually buying.
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.
Transformer oil testing cost: what lab DGA samples really charge, what fixed-interval sampling misses, and when an online dissolved hydrogen monitor pays off.
How to choose a dissolved hydrogen sensor for transformers in 2026: sensor classes, spec checks, fleet fit, and the path from single-gas alarm to nine-gas diagnosis.
What a transformer oil testing program covers in 2026: the DGA, moisture and electrical test battery, sampling frequency, IEEE/IEC standards, and lab vs online cost.
DGA monitor comparison for buyers: hydrogen-only sensors, multi-gas PAS and GC monitors, and portable analyzers compared by gas coverage, consumables, price and fit.
