Lesson F2 gave the lens; this lesson gives the method — how a steam audit actually runs, from the first data request to a report whose numbers survive hostile questions. The difference between an audit and a walk-around is discipline: measure first, estimate second, and label which is which. That honesty is also what separates the audits that get funded from the ones that get filed.

Phase one: the desk (before any site walk)

A day with the plant's own records finds half the story. Fuel and steam ledgers — twelve months of fuel purchases against production: the ₹/1000 kcal trend (B2) and the specific steam consumption per unit of product (F9's benchmark number). The evaporation ratio — steam metered ÷ fuel burned, against what B2's arithmetic predicts (~4.2 on practice-plant husk): a gap here is boiler drift or meter fiction, both findings. Make-up water — the single most revealing meter in the plant: make-up ≈ un-returned condensate + blowdown + losses, so one reading sizes wastes 2 and part of 1 before you have packed a bag. Drawings and set-points — the steam distribution scheme, PRS settings, trap schedule if one exists. Plants without these records get their first finding free: the audit's precondition is measurement (D8).

Phase two: the walk — instruments, not opinions

The kit is modest and decisive: an IR thermometer (surfaces, insulation gaps, trap lines), a contact/ultrasonic trap tester or at minimum the temperature-and-listen method of D5, a flue-gas analyser for the boiler (O₂, stack temperature — B4's indirect method live), a camera (every finding photographed with its tag number), and the F2 map as the route. The walk's rules: full production conditions (a Sunday audit measures a Sunday), every claim tied to an instrument reading or explicitly labelled an estimate, and the operators interviewed as colleagues — the fitter who nurses the far dryer knows waste №7 by first name, unlabelled.

1 · desk ledgers · ratios · make-up 2 · walk instruments + F2 map 3 · quantify each lesson's arithmetic 4 · rank ₹ · cost · payback · owner 5 · fix → measure again (F8) — the loop, not a line every number in phases 3–4 is labelled M (measured) or E (estimated) — the report's credibility lives in those letters
The method as a loop. Phase 5 is what makes it an engineering programme rather than a document.

Phase three: quantify like the lessons taught

Each finding gets its arithmetic from its home lesson — leaks by hole size (C9), flash by fraction (A8), surfaces by the flange tax (C7), traps by population statistics and spot measurements (D5), boiler losses by the indirect method (B4), return by the make-up meter (D6) — all priced at the plant's own ₹/1000 kcal (B2), never at a brochure's. Two disciplines keep the numbers defensible: label M or E against every figure (measured or estimated — reviewers forgive estimates, not disguises), and state the band, not the point where uncertainty is real ("₹14–19 lakh/yr" survives scrutiny; "₹17.42 lakh" invites it).

Phase four: the register that gets funded

The report's engine is one table: finding · annual ₹ · fix · cost · payback · owner · M/E label — ranked by payback, with the F2 pairings noted (the condensate project that shrinks three wastes at once deserves its combined case). Everything else — photos, method notes, meter lists — is appendix. And the last page is a promise: the re-measurement plan, naming which meters will prove each saving and when (lesson F8's territory). Audits that end with that page get their second year; audits that end with a congratulations paragraph do not.

At site
  • Start every audit at the make-up water meter and the fuel ledger — the two numbers that cannot lie about totals.
  • Walk at full production, instruments in hand, F2 map as the route, camera on everything. Opinions go in a separate notebook.
  • Label every figure M or E. Read your own report as the plant's most hostile accountant before issuing it.
  • End with the re-measurement plan. If a saving cannot name the meter that will prove it, flag it as such in the register.
Pin this
  • Desk first: fuel ledger, evaporation ratio, make-up meter — half the audit before the site walk.
  • Walk with instruments at full production; photograph and tag everything.
  • Quantify with each lesson's own arithmetic at the plant's own ₹/1000 kcal; label M or E; state bands.
  • One ranked register with owners and paybacks; close with the re-measurement plan.
Steam stories

The measure-first creed has a patron sentence: "When you can measure what you are speaking about, and express it in numbers, you know something about it" — Lord Kelvin, 1883, in a lecture on electrical units. Energy auditors quote him so often the line has become furniture, but the context bites: Kelvin was arguing against Victorian engineers who sized plant by feel and reputation. A century and a half later, every audit that begins at the make-up meter instead of the opinion book is keeping his argument alive.