{
  "description": "The carbon monoxide concentration the sensor measures, with its unit.",
  "type": "object",
  "properties": {
    "value": {
      "type": "object",
      "description": "A measurement value with optional null support",
      "properties": {
        "value": {
          "type": "number",
          "description": "The measured value"
        },
        "isNull": {
          "type": "boolean",
          "description": "True if the measurement is invalid/null",
          "default": false
        }
      },
      "required": [
        "value",
        "isNull"
      ],
      "additionalProperties": false,
      "title": "MeasurementValue"
    },
    "unit": {
      "type": "string",
      "description": "Unit of measurement",
      "enum": [
        "LUX",
        "PPM",
        "PPB",
        "PERCENT",
        "PASCAL",
        "LITERS_PER_MINUTE",
        "PERCENT_VOLUME",
        "PH",
        "SIEMENS_PER_METER",
        "METERS_PER_SECOND",
        "DEGREES_CELSIUS",
        "DEGREES_FAHRENHEIT"
      ]
    }
  },
  "required": [
    "value",
    "unit"
  ],
  "additionalProperties": false
}