The SDL500 Submersible Data Logger is a rugged, self-powered remote data logging system for deploying environmental sensors in or near water without fear of accidental flooding.



The SDL500 is designed with impact-resistant PVC, two elastomer bumpers, shock-mounted electronics and redundant seals. It can withstand extreme wave action, floods and underwater deployment to 200 ft.

Extended Battery Life

The SDL500 operates for months on eight D-cell alkaline batteries. For longer deployments, sixteen D-cell alkaline battery packs and solar charging options are available.

Sensor Connections

The SDL500 is configured with five sensor ports to interface with water quality sondes, water level sensors, soil sensors, and more. Supported sensor interfaces include RS-232, RS-485, SD-12, VDC, and mA.

Communication Options

Real-time telemetry options include cellular, radio, and satellite. All communication modules are securely housed within the submersible enclosure, and a waterproof antenna attaches to the top connector.

Buoy Integration

The CB-50 data buoy is designed to accommodate the NexSens SDL500 submersible data logging system for unattended deployment in lakes, rivers, and coastal waters.
Analog Inputs(2) differential or (4) single-ended, 0-2.5 V auto range, 12-bit resolution
Analog Outputs(1) 12-bit channel, 0-2.5 V programmable
Power Outputs(1) 12V 250 mA configurable switch; (1) 5V 100 mA switch excitation voltage; (1) 12V output, fused from battery
Pulse Counters(1) tipping bucket counter, max rate: 10 Hz
Digital I/O Ports(1) standard generic I/O port
1-Wire Interface(1) 1-wire temperature sensor port
SDI-12 Interface(1) SDI-12 port
RS-232 Interface(2) RS-232 sensor ports
RS-485 Interface(1) RS-485 port
Host Interface(1) RS-232 or RS-485 port configurable
Supported Serial Comm ProtocolsNMEA 0183 or Modbus RTU
Internal Memory2 MB Flash memory, over 500,000 data points minimum
Power RequirementsVoltage: 10.7 to 16 VDC
Typical Current DrawData Logger: 2.5 mA sleep, 10 mA processing, 36 mA analog measurement; Cellular Modem: 350 mA receive/transmit typical, 104 mA idle; Radio Modem: 86 mA receive, 500 mA transmit, 21 mA idle,< 1 mA power off; Satellite Modem: 550-850mA transmit, 80mA standby, 30uA sleep
Battery(8) D-cell alkaline batteries, internal; optional 12VDC power
Maximum Depth200 ft.
Temperature Range-20 to +70°C
Dimensions18.25” length x 5.5” diameter
Weight11.0 lbs. without batteries, 13.8 lbs. with batteries
Compatible Sensors4-20 mA sensors, 0-2.5 V sensors, SDI-12 sensors, RS-232 sensors, RS-485 sensors, Modbus RTU sensors, NMEA 0183 sensors, 1-Wire temperature sensors, Thermistor sensors, Tipping bucket rain gauges
Cellular ProtocolGSM/GPRS, EDGE, CDMA
Supported Cellular CarriersAT&T, Verizon, Sprint
Radio Frequency Range902-928 MHz
Radio Communication Range40 miles line of sight, extended range with repeaters
Satellite Frequency Range1616-1626.5 MHz