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    "USBR 1–8 ft Parshall free flow: Q_cfs = 4 W_ft Ha_ft^n, n=1.522 W_ft^{0.026}; SI W, Ha, Q; n is reported, not an input",
    "Ha is the specified-gage upstream head, not weir crest head H; W∈[0.3048 m, 2.4384 m]; Ha∈[0.03048 m, 1.6764 m]; free nappe only",
    "Not thin-plate (2/3) C_d L √(2g) H^{3/2}, not broad-crested (2/3)^{3/2} b √g H^{3/2}, not Manning n, not Q=Av, not orifice, not submerged Hb"
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    "USBR 1–8 ft Parshall free flow: Q_cfs = 4 W_ft Ha_ft^n, n=1.522 W_ft^{0.026}; SI W, Ha, Q; n is reported, not an input",
    "Ha is the specified-gage upstream head, not weir crest head H; W∈[0.3048 m, 2.4384 m]; Ha∈[0.03048 m, 1.6764 m]; free nappe only",
    "Not thin-plate (2/3) C_d L √(2g) H^{3/2}, not broad-crested (2/3)^{3/2} b √g H^{3/2}, not Manning n, not Q=Av, not orifice, not submerged Hb"
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    "W outside [0.3048, 2.4384] m or Ha outside [0.03048, 1.6764] m → VALUE_OUT_OF_RANGE",
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      "title": "ISO 9826 — Measurement of liquid flow in open channels — Parshall and SANIIRI flumes",
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      "supports": "Parshall geometry and free-flow rating; not a thin-plate or broad-crested weir",
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      "supports": "Q_cfs = 4 W_ft Ha_ft^n with n = 1.522 W_ft^{0.026}",
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      "section": "Volume flow rate",
      "url": "https://www.iso.org/standard/31895.html",
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