[
  {
    "id": "urn:example:observation:42",
    "metric": {
      "value": "mass",
      "scheme": "https://example.org/metrics/v1"
    },
    "quantity": {
      "value": "12.75",
      "unitCode": "KGM",
      "unitScheme": "https://unece.org/code-list-recommendations"
    },
    "observedAt": "2026-09-08T08:00:00Z"
  }
]