@prefix cpm: . @prefix dc: . @prefix dcat: . @prefix dce: . @prefix dct: . @prefix dcterms: . @prefix grg: . @prefix iop: . @prefix ns0: . @prefix ns1: . @prefix owl: . @prefix pav: . @prefix prov: . @prefix puv: . @prefix qudt: . @prefix rdf: . @prefix rdfs: . @prefix reg: . @prefix sdo: . @prefix semapv: . @prefix skos: . @prefix sssom: . @prefix void: . @prefix xsd: . rdf:type sdo:DefinedTerm ; sdo:description "A non-dispersive infrared gas analyzer that measures carbon dioxide and water vapour concentrations in the atmosphere. The power received from the infrared source is measured at three wavelengths: one at a wavelength that is absorbed by carbon dioxide, another at a wavelength that is absorbed by water, and the third at a non-absorbing reference wavelength. The absorbance of each gas is calculated and converted to molar fraction using density, pressure and temperature data." ; sdo:inDefinedTermSet ; sdo:name "LI-COR 7500 infrared gas analyser"@en ; sdo:termCode "TOOL0085" .