Mass ratio or mass fraction: Dimensionless ratio of masses. Used for water content, composition, concentration (mass basis), and mass ratios. Commonly expressed as percent (%), fraction, ppm (part per million), or kg/kg.
The unit of measure for mass ratio or mass fraction.
Source
<complexType name="MassPerMassMeasureType"><annotation><documentation>Mass ratio or mass fraction: Dimensionless ratio of masses. Used for water content, composition, concentration (mass basis), and mass ratios. Commonly expressed as percent (%), fraction, ppm (part per million), or kg/kg.</documentation></annotation><simpleContent><extension base="diggs:DescriptorValueType"><attribute name="uom" type="diggs:MassPerMassUomEnumType"><annotation><documentation>The unit of measure for mass ratio or mass fraction.</documentation></annotation></attribute></extension></simpleContent></complexType>
<attribute name="uom" type="diggs:MassPerMassUomEnumType"><annotation><documentation>The unit of measure for mass ratio or mass fraction.</documentation></annotation></attribute>