@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 semapv: . @prefix skos: . @prefix sssom: . @prefix void: . sssom:object_id . skos:member . sssom:subject_id . skos:narrower . dc:isVersionOf . rdf:type skos:Concept ; dce:identifier "SDN:L22::TOOL0578" ; dc:date "2012-12-18 15:09:37.0" ; dc:identifier "SDN:L22::TOOL0578" ; pav:authoredOn "2012-12-18 15:09:37.0" ; pav:hasCurrentVersion ; pav:version "1" ; void:inDataset ; owl:deprecated "false" ; owl:versionInfo "1" ; skos:altLabel "Plessey M021" , "Plessey M021"@en ; skos:broader , ; skos:definition "An axial flow impeller current meter designed to operate at depths to 1000 m, and in temperatures from -4 to 35 degC. Forward currents rotate the impeller clockwise, and reverse currents rotate it anticlockwise (starting speed 2 cm/s; speed range 5 to 250 cm/s; accuracy greater of 3 cm/s or 3 percent). A counter is magnetically coupled to the impeller, and records net current speed over the sample period. A vane with horizontal stabiliser fins aligns the impeller with the current flow. Current direction is measured by magnetic compass (tolerated tilt range is 15 degrees in both pitch and roll axes). Pre-1972 instruments were equipped with a battery-driven clock (accuracy better than 10 sec/day), whereas post-1972 instruments used a solid state crystal clock (accuracy 2 sec/day)."@en ; skos:inScheme ; skos:notation "SDN:L22::TOOL0578" ; skos:note "accepted"@en ; skos:prefLabel "Plessey recording current meter model M021"@en ; skos:related . sssom:subject_id . skos:narrower . skos:narrower . skos:related . sssom:subject_id . sssom:object_id . skos:related . skos:narrower . sssom:object_id .