The CTD/S4 is a lightweight, self-contained, intelligent water quality monitoring and recording instrument for oceanic and inland waters. Small size and light weight make the CTD/S4 ideally suited to profiling applications, and easily deployable from small vessels.

Standard parameters include Conductivity, Temperature and Depth. Optional Sensors available include Turbidity, OBS, pH, Dissolved Oxygen, Redox and Sound Velocity.

Up to 20M bytes of internal memory are available for data storage, allowing storage of 3 million C, T, and D data samples. All communication, programming and data retrieval are accomplished without opening the instrument housing via a four-pin waterproof connector.

The CTD/S4 may be programmed for logging to internal memory or for external, real-time logging. In addition, the operating mode may be programmed to vary such characteristics as channels recorded, sampling rate, and recording interval.

Communication with the CTD/S4 is via a standard RS232C serial link interface. The Baud-rate can be set from 300 Baud to 19,200 Baud. The scan rate for fast profiling is 10 samples per second. Data may be sent over cable 1,000 meters in length for real-time logging. Real-time logging may be accomplished using a four-conductor shielded cable.