Dataset: CTD - Press Temp Sal O2
Deployment: VDT0410

Refer to SAGE Voyage Report

CTD-related instrumentation consisted of:
  * a Seabird Electronics (SBE) 911plus CTD with:
  - SBE-5 pumped SBE-3 temperature, SBE-4 conductivity and SBE-43 dissolved oxygen sensors.
  - SBE-5 pumped secondary SBE-3 temperature and SBE-4 conductivity sensors.
  - Seapoint Sensors, Inc. SCF chlorophyll fluorometer.
  - 25-cm Wetlabs C-star transmissometer.
  - Biosherical Instruments Inc. photosynthetic ally active radiation (PAR) sensor, model QSP200L4S.
  - Datasonics sonar altimeter, model PSA-900D.
  - a SBE 32 24x10-litre Carousel water sampler.
  - Ocean Test Equipment Standard BES external-spring Niskin-type water-sampling bottles.
  - Salinity sample bottles.
  - CTD winch with 10-km 10.5-mm single-core seacable.

Performance: With the exception of issues noted below, the CTD-related instrumentation apparently functioned to specification and was operated essentially according to accepted practices for the duration of the voyage. A total of 85 one-cast CTD stations were completed, labelled u3502 to u3743.

PAR Sensor: The initial CTD PAR sensor experienced an intermittent fault that manifested as a time variable offset, both cast to cast and, less evidently, within casts. It was eventually replaced with a formally identical spare unit for station u3719 cast 1 and subsequent casts.

Secondary Conductivity Sensor: The initial secondary conductivity sensor eventually developed a clear fault (during station u3740 cast 1). It was replaced with a formally identical spare unit for station u3740 cast 1 and subsequent casts. The development of this fault was perhaps somewhat progressive, as possibly indicated by slight shifts in the primary-secondary conductivity difference on casts before station u3740 cast 1.