Verification
5/5 calculation tests · Production surface contract 1/1
- Golden tests 0 / 0
- Boundary tests 0 / 0
- Property tests 5 / 5
- Production surface contract 1 / 1
}
- Engine tested Yes
- Source checked Yes
- Artifact integrity PASS
- Production attestation Embedded snapshot: STALE · Last attested schema matched 1.0.0 snapshot / local build · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · Public/cache ✓ · Origin ✓ · Live production status PASS (0 stale; 164 CURRENT) @ 2026-09-18T02:44:05.986Z
- Semantic contract PASS
- Evidence attested at 2026-09-18T02:44:05.231Z
- Last production check 2026-09-18T02:44:05.231Z
- Public / cache PASS
- Origin PASS
- Supplemental domain review Not performed
- Named expert review Not performed
- release artifacts aligned PASS
Fingerprint sha256:972a238c52de065d2f64860739d19d48f25546ba56ff2fcf069e6d0327eaa2e7
Input schema sha256:e0952670b41b6a8e44743cd8bfd90a0a3e9a0546a7171f049f83b414bbbfc9db · Output schema sha256:a9150d32f3b394410472be0f139614d280219a6c446223ebbb7ee49210fd11a1 · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write
(published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.
Engine identity and declared limitations.
- Tool
- cutthroat-flume
- Engine
- cutthroat-flume
- Engine build
- 2026-09-18
- Evidence core
- 2026-09-18T02:23:57.439Z
- Rendered
- 2026-09-18T03:31:40.489Z
- Last reviewed
- —
Assumptions
- Skogerboe cutthroat free flow: Q_cfs = C Ha_ft^n; C=3.50 W_ft^{1.025} (L_f/3 ft)^{0.020}; n=1.56 (L_f/3 ft)^{0.026}; SI W, L_f, Ha, Q; C and n are reported, not inputs
- No diverging section; L_f is independent flume length, not weir crest L; W < L_f; L_f∈[0.4572 m, 2.7432 m]; W∈[0.0508 m, 1.8288 m]; Ha∈[0.03048 m, 1.2192 m]
- Not Parshall 4 W_ft Ha^{1.522 W^{0.026}}, not thin-plate weir, not broad-crested (2/3)^{3/2} √g, not Manning n, not Q=Av, not orifice, not submerged Hb
Limitations
- Skogerboe cutthroat free flow: Q_cfs = C Ha_ft^n; C=3.50 W_ft^{1.025} (L_f/3 ft)^{0.020}; n=1.56 (L_f/3 ft)^{0.026}; SI W, L_f, Ha, Q; C and n are reported, not inputs
- No diverging section; L_f is independent flume length, not weir crest L; W < L_f; L_f∈[0.4572 m, 2.7432 m]; W∈[0.0508 m, 1.8288 m]; Ha∈[0.03048 m, 1.2192 m]
- Not Parshall 4 W_ft Ha^{1.522 W^{0.026}}, not thin-plate weir, not broad-crested (2/3)^{3/2} √g, not Manning n, not Q=Av, not orifice, not submerged Hb
Sources
Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.
- Skogerboe, G.V.; Hyatt, M.L.; England, J.D.; Johnson, J.R. — Design and Calibration of Submerged Open Channel Flow Measurement Structures, Part 3: Cutthroat Flumes — 3-ft family free-flow rating
Supports: C=3.50 W_ft^{1.025} and n=1.56 at L_f=3 ft; L-scaled n and C; not a Parshall 4 W rating
- ISO 80000-4 — Mechanics — Volume flow rate
Supports: Q is volume flow; W, L_f, and Ha are lengths
Published checks
Golden, boundary, and property cases included in this evidence build.
| ID | Kind | Status | Detail |
|---|
property-ctf-q | property | pass | 3 ft / 1 ft / 1 ft Ha → 3.50 cfs |
property-ctf-n | property | pass | n=1.56 at L_f=3 ft |
property-ctf-not-parshall | property | pass | Q≠Parshall 4 cfs |
property-ctf-roundtrip-Ha | property | pass | Ha invert |
property-ctf-model | property | pass | cutthroat_skogerboe_free |
