Operation of CTD-rosette sampler systems

The CTD-rosette system is best operated from amidships to minimize effects of pitch and roll on the data. When all electrical connections work properly, the CTD should not be switched off throughout the cruise. 

To make near-bottom measurements one must know the distance to the bottom when the CTD-rosette approaehes the bottom, to avoid damage. Most frequently, the distance is measured independently with an acoustic pinger that is attached to the rosette frame. In 

The logsheet is prepared. It contains a check list for preparation of the CTD-rosette that follows the manufacturer s recommendations and the operator s experience with individual systems. Make sure by intensive rinsing with fresh water that all mechanical parts of the rosette work properly. Data acquisition starts before the CTD is lowered into the sea as inair data are needed for later processing. 

In order not to avoid damage by compression, bottles are closed on the way up at the desired pressure levels. On the way up, the CTD sensors are in the wake of the system which leads to noisier data. It is therefore best to stop the winch before closing a bottle. 

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