π Uno β The βUnitβ for Dimensionless Quantities
π Measurement
In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement. Commonly used are parts-per-million (ppm, 10β6), parts-per-billion (ppb, 10β9), parts-per-trillion (ppt, 10β12) and parts-per-quadrillion (ppq, 10β15). This notation is not part of the International System of Units (SI) system and its meaning is ambiguous.
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- "Uno β The βUnitβ for Dimensionless Quantities" | 2021-07-01 | 131 Upvotes 115 Comments