> Completed synthetic counterpart: `virtual-validation.html`, regenerated by `python run.py`. `completion.json` records the executed cases. The physical procedure below is retained for a real installation; it is not presented as unfinished computational work or as an executed physical test.

# Physical calibration procedure — not executed

1. Record the selected bridge, ADC, excitation/reference arrangement, common-mode range, analog filter and mounting configuration. Confirm overload and environmental limits from actual component documents.
2. Stabilize the assembly and log unloaded output and temperature. Record warm-up time, sampling rate and full raw counts. Confirm the pan is empty before applying tare or zero tracking.
3. Use traceable reference masses spanning the intended working range. Record their certificate uncertainties and loading procedure. Collect multiple ascending and descending cycles, with dwell periods sufficient for settling.
4. Fit calibration from designated calibration cycles only. Validate on withheld loads and cycles. Plot residuals against mass, direction, time and temperature; a small fitted residual is not sufficient evidence of accuracy.
5. Measure repeatability, creep under a sustained load, hysteresis and zero recovery. Repeat over the intended temperature range. Replace the synthetic inputs and assumed uncertainty bounds with this evidence, retaining correlations where appropriate.
6. Apply a load step and verify noise and settling using time-aligned reference events. Check clipping, aliasing, excitation disturbances, electromagnetic interference and restart behavior.
7. Verify that a sustained real load is not removed by software. Keep automatic zero tracking off unless the external empty-pan indication is trustworthy for the application. Test mistaken or missing confirmations explicitly.
8. Produce a dated calibration record with reference-mass identities, environmental conditions, fitted coefficients, covariance, residuals, accepted working range and uncertainty. Nothing in this download is that record.