@prefix cpm: . @prefix dc: . @prefix dcat: . @prefix dce: . @prefix dct: . @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: . skos:member . skos:narrower . skos:narrower . skos:narrower . skos:related . skos:related . skos:narrower . skos:altLabel "Plessey 9021" , "Plessey 9021"@en ; skos:broader , ; skos:definition "An axial flow impeller current meter designed to operate at depths to 2000 m (6000 m optional), and in temperatures from -5 to 40 degC. Forward currents rotate the impeller clockwise, and reverse currents rotate it anticlockwise (starting speed 1.5 cm/s; speed range 2.5 to 500 cm/s; accuracy greater of 2 cm/s or 2 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 (minimum current velocity for alignment 3 cm/s). Current direction is measured by magnetic compass (360 degree range; accuracy 3 degrees; resolution 1.4 degrees; tolerated tilt rangeis -1 degrees to 4 degrees, or up to 40 degrees if gimballed). A solid state crystal clock measures time (accuracy better than 2 sec/day). Optional sensors include platinum resistance thermometer (range -2 to 35 degC; accuracy 0.1 degC; 99 percent response time 15 sec), pressure sensor (accuracy 0.5 percent of full scale; response time 10 msec), conductivity sensor and sample counter."@en ; skos:inScheme ; skos:notation "SDN:L22::TOOL0577" ; skos:note "accepted"@en ; skos:prefLabel "Plessey recording current meter model 9021"@en ; skos:related .