The Elsmar Cove Forum and Site Map The Elsmar Cove Wiki More Free Files The Elsmar Cove Forums Discussion Thread Index Post Attachments Listing Failure Modes Services and Solutions to Problems Elsmar cove Forums Main Page Elsmar Cove Home Page

Parts Per Million

From Elsmar Cove Quality Assurance and Business Standards Wiki
Jump to: navigation, search

Parts per Million (aka PPM or ppm)

Parts-per notation is used, especially in science and engineering, to denote relative proportions in measured quantities; particularly in low-value (high-ratio) proportions at the parts-per-million (ppm) 10–6, parts-per-billion (ppb) 10–9, and parts-per-trillion (ppt) 10–12 level. Since parts-per notations are quantity-per-quantity measures, they are known as dimensionless quantities; that is, they are pure numbers with no associated units of measurement. In regular prose, parts-per notations generally take the literal “parts per” meaning of a comparative ratio. However, in mathematical expressions, parts-per notations function as coefficients with values less than 1.

While many disciplines see this as 'their' measurement (such as automotive), it is used in all science disciplines.

Also see:

PPM - Parts per Million

PPM (Parts per Million) discussion threads