Mooring diagram by Jim Johnson

The Conductivity Temperature Depth recorder (CTD) is an oceanographic sampling instrument with electronic sensors to continuously measure salinity, temperature and depth. The rosette contains Niskin bottles that are large PVC plastic cylinders with spring loaded caps that close at both ends. As the stainless steel frame rosette is lowered, the end caps are open and water can pass through.   Each bottle is then triggered to close at the desired depth and take a sample. These bottles were then returned to the surface and water samples were removed for analysis.

NEMO 1999 - Teacher's Logbook - http://newport.pmel.noaa.gov/nemo1999/teacherlog.html
 
 
 

CTD Rosette being submerged to collect water samples.

Image ID: corp2473, NOAA Corps Collection
Photo Date: 1998 February
Photographer: Michael Van Woert, NOAA NESDIS, ORA