The YSI 6600 Multiparameter Instrument, is designed for long-term in situ monitoring and profiling of CTD PH Chlorophyll, Turbidity and Rhodamine. This sonde offers the longest battery life and has the largest memory of any YSI 6-Series Sonde.

The 6600 is the only YSI instrument that can be deployed to 200 meters. It uses standard YSI 6-Series probes, including YSI's Rapid Pulse stirring-independent dissolved oxygen sensor, and self-cleaning turbidity which is not affected by variations in ambient light.

It will log all of the parameters at programmable intervals and store 150,000 readings. At 15-minute intervals, it will log data unattended for about 75 days.