Dimensionless Qn?

Some calculated values do not have a unit attached as these are ratio’s of identical units. An example is the relative specific weight of a component (e.g. relative to the specific weight of water). Is it UCUM proof to report this number without a unit, or should this be reported as kg/m3/kg/m3? There may be more (or better) examples. So an universal answer would be appreciated. Out goal is to have LIS’s assist is comparing identity of units when exchanging lab data between health care providers.

Good question Dirk.


In the US, I’ve seen unitless ratios, but usually as part of a panel so you can tell what the units are for the 2 calculated result values. From a computer usability (and perhaps human), it would be more clear to have the units in the ratio, especially if the ratio is “separated” from the values used in its calculation.