{
  "id": "fedrel/fm21-n",
  "slug": "fm21-n",
  "brand": "fedrel",
  "model_code": "FM21 N",
  "title": "FM21 N",
  "technology": "ultrasonic-clamp-on",
  "description": "Portable ultrasonic, 0-12 m/s, ±1% accuracy, printed ±3% repeatability, IP54 transmitter/IP68 transducer, 4-20 mA, 2 GB SD storage, 11.1 V rechargeable battery, 5 m cable",
  "notes": "Connection and size scope: 25-1200 mm, external clamp-on",
  "facts": {
    "model": {
      "value": "FM21 N",
      "status": "manufacturer_claim",
      "source": {
        "document": "Fedrel product and price list",
        "document_date_or_revision": "effective 20 January 2026",
        "page_or_section": "8, 12, 14",
        "exact_model_and_configuration": "FM21 N; documented family, size/options require confirmation"
      }
    },
    "manufacturer": {
      "value": "Fedrel",
      "status": "manufacturer_claim",
      "source": {
        "document": "Fedrel product and price list",
        "document_date_or_revision": "effective 20 January 2026",
        "page_or_section": "8, 12, 14",
        "exact_model_and_configuration": "FM21 N; documented family, size/options require confirmation"
      }
    },
    "configuration_code": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "measuring_principle": {
      "value": "ultrasonic clamp on",
      "status": "editorial_guidance",
      "source": {
        "document": "Fedrel product and price list",
        "document_date_or_revision": "effective 20 January 2026",
        "page_or_section": "8, 12, 14",
        "exact_model_and_configuration": "FM21 N; documented family, size/options require confirmation"
      }
    },
    "installation_style": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "fluid_compatibility": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "conductivity_min_uS_cm": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "solids_limits": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "dn_mm": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "actual_internal_diameter_mm": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "q1_m3_h": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "q2_m3_h": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "q3_m3_h": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "q4_m3_h": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "r_ratio": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "legacy_flow_ratings_with_standard": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "flow_min_m3_h": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "flow_max_continuous_m3_h": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "flow_peak_m3_h": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "peak_duration_limit": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "accuracy_expression": {
      "value": "±1%",
      "status": "manufacturer_claim",
      "source": {
        "document": "S17: fedrel Feb 2026 final.pdf",
        "document_date_or_revision": "Effective 20 January 2026",
        "page_or_section": "13",
        "exact_model_and_configuration": "FM21 N; this document scope only"
      }
    },
    "accuracy_basis": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "accuracy_conditions": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "orientation": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "temperature_fluid_C": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "temperature_ambient_C": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "working_pressure_bar_at_temperature": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "pressure_loss_curve": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "wetted_materials": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "connection_standard_and_size": {
      "value": "Clamp-on; stated pipe-size range 25–1200 mm",
      "status": "manufacturer_claim",
      "source": {
        "document": "S17: fedrel Feb 2026 final.pdf",
        "document_date_or_revision": "Effective 20 January 2026",
        "page_or_section": "13",
        "exact_model_and_configuration": "FM21 N; this document scope only"
      }
    },
    "face_to_face_mm": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "straight_runs_and_conditions": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "sensor_ip_and_immersion_conditions": {
      "value": "Encapsulated IP68 transducer",
      "status": "manufacturer_claim",
      "source": {
        "document": "S17: fedrel Feb 2026 final.pdf",
        "document_date_or_revision": "Effective 20 January 2026",
        "page_or_section": "13",
        "exact_model_and_configuration": "FM21 N; this document scope only"
      }
    },
    "transmitter_ip": {
      "value": "IP54",
      "status": "manufacturer_claim",
      "source": {
        "document": "S17: fedrel Feb 2026 final.pdf",
        "document_date_or_revision": "Effective 20 January 2026",
        "page_or_section": "13",
        "exact_model_and_configuration": "FM21 N; this document scope only"
      }
    },
    "power_configuration": {
      "value": "11.1 V rechargeable lithium battery",
      "status": "manufacturer_claim",
      "source": {
        "document": "S17: fedrel Feb 2026 final.pdf",
        "document_date_or_revision": "Effective 20 January 2026",
        "page_or_section": "13",
        "exact_model_and_configuration": "FM21 N; this document scope only"
      }
    },
    "battery_life_and_assumptions": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "included_outputs": {
      "value": "4–20 mA",
      "status": "manufacturer_claim",
      "source": {
        "document": "S17: fedrel Feb 2026 final.pdf",
        "document_date_or_revision": "Effective 20 January 2026",
        "page_or_section": "13",
        "exact_model_and_configuration": "FM21 N; this document scope only"
      }
    },
    "optional_outputs": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "protocol_and_map": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "pulse_litres_per_pulse": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "measurement_log_transmit_intervals": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "offline_storage_and_backfill": {
      "value": "2 GB SD card; log format not supplied",
      "status": "manufacturer_claim",
      "source": {
        "document": "S17: fedrel Feb 2026 final.pdf",
        "document_date_or_revision": "Effective 20 January 2026",
        "page_or_section": "13",
        "exact_model_and_configuration": "FM21 N; this document scope only"
      }
    },
    "approvals_exact_scope": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "included_accessories": {
      "value": "Transducers, handheld device, charger, 5 m cable, chain, railing and coupling compound",
      "status": "manufacturer_claim",
      "source": {
        "document": "S17: fedrel Feb 2026 final.pdf",
        "document_date_or_revision": "Effective 20 January 2026",
        "page_or_section": "13",
        "exact_model_and_configuration": "FM21 N; this document scope only"
      }
    },
    "recurring_costs": {
      "value": null,
      "status": "unknown",
      "source": null
    },
    "documented_description": {
      "value": "Portable ultrasonic, 0-12 m/s, ±1% accuracy, printed ±3% repeatability, IP54 transmitter/IP68 transducer, 4-20 mA, 2 GB SD storage, 11.1 V rechargeable battery, 5 m cable",
      "status": "manufacturer_claim",
      "source": {
        "document": "Fedrel product and price list",
        "document_date_or_revision": "effective 20 January 2026",
        "page_or_section": "8, 12, 14",
        "exact_model_and_configuration": "FM21 N; documented family, size/options require confirmation"
      }
    },
    "documented_features": {
      "value": "Connection and size scope: 25-1200 mm, external clamp-on",
      "status": "manufacturer_claim",
      "source": {
        "document": "Fedrel product and price list",
        "document_date_or_revision": "effective 20 January 2026",
        "page_or_section": "8, 12, 14",
        "exact_model_and_configuration": "FM21 N; documented family, size/options require confirmation"
      }
    },
    "documented_size_scope": {
      "value": "25-1200 mm, external clamp-on",
      "status": "manufacturer_claim",
      "source": {
        "document": "Fedrel product and price list",
        "document_date_or_revision": "effective 20 January 2026",
        "page_or_section": "8, 12, 14",
        "exact_model_and_configuration": "FM21 N; documented family, size/options require confirmation"
      }
    },
    "repeatability": {
      "value": "±3% printed; anomalous relative to accuracy, obtain clarification",
      "status": "manufacturer_claim",
      "source": {
        "document": "S17: fedrel Feb 2026 final.pdf",
        "document_date_or_revision": "Effective 20 January 2026",
        "page_or_section": "13",
        "exact_model_and_configuration": "FM21 N; this document scope only"
      }
    },
    "flow_velocity_range": {
      "value": "0–12 m/s",
      "status": "manufacturer_claim",
      "source": {
        "document": "S17: fedrel Feb 2026 final.pdf",
        "document_date_or_revision": "Effective 20 January 2026",
        "page_or_section": "13",
        "exact_model_and_configuration": "FM21 N; this document scope only"
      }
    }
  },
  "source": {
    "document": "Fedrel product and price list",
    "document_date_or_revision": "effective 20 January 2026",
    "page_or_section": "8, 12, 14",
    "exact_model_and_configuration": "FM21 N; documented family, size/options require confirmation"
  },
  "size_values": [
    25,
    1200
  ],
  "connections": [
    "clamp-on"
  ],
  "outputs": [
    "4-20ma"
  ],
  "power": [
    "battery"
  ],
  "services": [
    "water"
  ],
  "conflicts": [
    [
      "Accuracy and repeatability",
      "Fedrel effective 20 January 2026 list p.12: ±1% accuracy",
      "Same entry prints ±3% repeatability; definitions/correction required"
    ]
  ],
  "price_band": null,
  "last_reviewed": "2026-09-09",
  "facet_note": "Discovery tags come from the documented description, including optional capabilities. Confirm inclusion and exact size/configuration."
}