The Clinical Measurement Ontology (CMO), Measurement Methods Ontology (MMO), and Experimental Condition Ontology (XCO) are currently being developed at the Rat Genome Database. For more information about these vocabularies please see Shimoyama et al. Three ontologies to define phenotype measurement data. Front Genet. 2012;3:87. Epub 2012 May 28 or contact us (http://rgd.mcw.edu/contact/index.shtml).
The measurement of transmittance (a linear scale from 0-100%) or absorbance (a logarithmic scale from zero to infinity) of particular wavelengths of light by the use of filters. Concentration values of solutes are calculated from measured values.