{
  "schema": "piping-educational-sensing-method/v1",
  "object_id": "c22-differential-level",
  "authority": "Authored static teaching reconstruction of source-described density/reference-path mechanisms; not selected fluid/hookup or project acceptance",
  "method": "delta_p_head=g*(sum(rho_i*h_i)-rho_r*H_r);h_ind=delta_p_head/(rho_cal*g)",
  "pressure_reference": "High-minus-low pressure difference; common gas pressure and known fixed installation offsets removed, no absolute-pressure multiplication",
  "inputs": {
    "g_m_per_s2": 9.80665,
    "calibration_density_kg_per_m3": 750,
    "layers": [
      {
        "density_kg_per_m3": 750,
        "vertical_depth_m": 1
      },
      {
        "density_kg_per_m3": 1050,
        "vertical_depth_m": 0.2
      }
    ],
    "additional_low_side_continuous_column": {
      "density_kg_per_m3": 800,
      "vertical_head_m": 0.3
    }
  },
  "results": {
    "actual_depth_m": 1.2,
    "head_without_added_reference_Pa": 9414.384,
    "indicated_without_added_reference_m": 1.28,
    "density_only_error_m": 0.08000000000000007,
    "additional_reference_head_Pa": 2353.596,
    "difference_with_added_reference_Pa": 7060.7880000000005,
    "indicated_with_added_reference_m": 0.9600000000000002,
    "combined_error_m": -0.23999999999999977
  },
  "conditions": [
    "Static separated layers and uniform layer densities",
    "Vertical head, not inclined path length",
    "Negligible gas-column contribution in simplified residual account",
    "Known fixed high/low installation offsets already removed",
    "Additional low-side head represents a continuous column supplying pressure to low port",
    "Local pools with gas communication around them need actual pressure path",
    "Unknown interfaces cannot generally be uniquely inferred from one reading"
  ],
  "project_acceptance": false
}