parts per million

{
  "id": "NISTu400",
  "unitsml_id": "u:parts_per_million",
  "name": "parts per million",
  "names": [
    {
      "value": "parts per million",
      "lang": "en"
    }
  ],
  "symbols": {
    "unicode": "ppm",
    "ascii": "ppm",
    "html": "ppm",
    "latex": "\\ensuremath{\\mathrm{ppm}}",
    "id": "ppm",
    "mathml": "<mi mathvariant='normal'>ppm</mi>"
  },
  "identifiers": [
    {
      "type": "nist",
      "id": "NISTu400"
    },
    {
      "type": "unitsml",
      "id": "u:parts_per_million"
    }
  ],
  "references": [
    {
      "type": "informative",
      "authority": "ucum",
      "uri": "ucum:unit:dimless:code:[ppm]"
    },
    {
      "type": "informative",
      "authority": "qudt",
      "uri": "http://qudt.org/vocab/unit/PPM"
    }
  ],
  "short": "parts_per_million",
  "root": false,
  "composite": false,
  "quantities": [
    {
      "id": "NISTq186",
      "name": "mass fraction",
      "type": "derived"
    }
  ],
  "dimension": {
    "id": "NISTd85",
    "name": "mass mole fraction",
    "expression": "1",
    "components": [],
    "dimensionless": true
  },
  "scale": {
    "id": "continuous_ratio",
    "name": "continuous ratio scale"
  },
  "systems": [
    {
      "id": "SI_derived_non-special",
      "name": "SI-derived units non-special",
      "short": "si-derived-nonspecial",
      "acceptable": true
    },
    {
      "id": "SI_compatible",
      "name": "Units compatible with SI",
      "short": "si-compatible",
      "acceptable": true
    }
  ],
  "root_units": null
}