The OCEAN SEVEN 320Plus WOCE-CTD multiparameter probe is the result of Idronaut's 25-year-old experience in the design and manufacturing of high quality fast response CTDs. The OCEAN SEVEN 320Plus CTD well meets the WOCE programme accuracy, precision and resolution specifications. The CTD can be easily equipped with an additional redundant conductivity and temperature (CT) sensor pair without the need for underwater connectors. The CT redundant sensors permit the gathering of extremely precise data with a verifiable data quality. The OCEAN SEVEN 320Plus WOCE-CTD is equipped with the well-known IDRONAUT full ocean depth, pump-free and long-term stability sensors. Central to which, is the high accuracy seven-platinum-ring quartz conductivity cell (patented), which can be cleaned in the field without the need for re-calibration. This unique quartz cell employs a large diameter (8 mm) and a short length (46 mm) to guarantee self-flushing and no clogging after long-term deployment even in biologically active waters. Competitors' sensors, which present few mm only of cell orifice and very long cell length, are prone to clog even if protected by dangerous and poisonous antifouling devices. The OCEAN SEVEN 320Plus WOCE-CTD multiparameter probe does not require pumps or any other external device to flush the sensors, which minimizes its power consumption and allows the use in Arctica and Antarctica. However, pump is optional. Acquired data is output using the standard RS232C interface or the telemetry option available for on-line full ocean depth real-time data transmission. Other interfaces like RS422 and wireless Bluetooth© can be optionally installed.