parts per million, ppm (unit)

{
    "$id": "https://schemas.anyterial.se/defs/v0.1/units/general/ppm",
    "$schema": "https://schemas.optimade.org/meta/v1.2/optimade/physical_unit_definition.json",
    "title": "parts per million",
    "symbol": "ppm",
    "display-symbol": "ppm",
    "description": "A dimensionless ratio of one part in one million.",
    "x-optimade-definition": {
        "label": "ppm_general",
        "kind": "unit",
        "format": "1.2",
        "version": "0.1.0",
        "name": "ppm"
    },
    "standard": {
        "name": "gnu units",
        "version": "3.15",
        "symbol": "ppm"
    }
}