. "Dimensionless unit for concentration. Recommended practice is to use specific units such as \\(ug/l\\)."^^ . . "\u2030" . "per mil" . "Parts per thousand"@en . . "http://aurora.regenstrief.org/~ucum/ucum.html#section-Derived-Unit-Atoms"^^ . . . "NX" . . . . . "\u2030" . . "0.001"^^ . "[ppth]"^^ . . .