Example 4 — Pressure transmitter, coefficients-only external certificate

Exercises the coefficients-only wizard path — for sensors that arrive with a calibration certificate stating the calibration polynomial directly, with no raw reference/measured data points to re-fit.

4.0 Setup

Asset (Assets → New Asset):

One channel:

Nothing else is required — a coefficients-only calibration doesn't consult accuracy, resolution, or measurement uncertainty (there's no analysis run to fold them into).

4.1 Wizard — Step 1 (General info)

Checking the box swaps Step 2 from raw-data entry to a coefficient-entry form, and the step indicator relabels to "Coefficients" / "Review" instead of "Raw Data" / "Analysis".

4.2 Wizard — Step 2 (Coefficients)

The certificate states: reference ≈ 1.0025 × measured − 0.42 kPa, valid 0–1000 kPa, expanded uncertainty ±1.2 kPa (k=2).

The equation preview reads: $f(x) = 1.0025x - 0.42\ \text{(kPa)}$.

4.3 Wizard — Step 3 (Review) and what gets saved

There's no analysis to run, so Step 3 echoes back the equation, valid range, and stated uncertainty for a final check before saving. On save:

• poly_order = 1, poly_coefficients = [1.0025, -0.42], range_min = 0, range_max = 1000, valid_range_min = 0, valid_range_max = 1000.
• expanded_uncertainty = 1.2, coverage_factor = 2, combined_uncertainty = 1.2 / 2 = 0.6.
• uncertainty_budget = [{ source: "external_certificate_stated", value: 1.2, divisor: 2, standard_uncertainty: 0.6, ... }] — a single row, not decomposed into Type A/B parts, since the certificate only gives one overall figure.
• r_squared, rmse, standard_error, max_error, decision_rule, and conformity_statement are all null — with no raw data there's no fit to score and no assessed error to check against a spec, so Open Gauge doesn't display a CONFORMS/DOES NOT CONFORM badge for this record (see Coefficients-only calibrations).

Expected results