The X2-SDL Submersible Data Logger is a rugged, self-powered data logging and telemetry system for deploying environmental sensors in or near water without fear of accidental flooding.



The X2-SDL 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.

Underwater Connectors

All connections are made with a simple waterproof thread-in connector. This removes the complications and errors associated with connecting individual wires.

Extended Battery Life

The X2-SDL operates for months on sixteen D-cell alkaline batteries. For longer deployments, extra alkaline battery packs and solar charging options are available.


When communicating via wireless telemetry, measurement data streams directly to the WQData LIVE web datacenter.

Communication Options

Real-time telemetry options include cellular, satellite, and radio. All communication modules are securely housed within the submersible enclosure, and a waterproof antenna is integrated on the top of the device.

Measurement Versatility

The X2-SDL is configured with three sensor ports to interface with multi-parameter sondes, water quality sensors, temperature strings, Doppler velocity meters, water level sensors, and more. Supported sensor interfaces include SD-12, RS-485 and RS-232.

Buoy Integration

The CB-50 data buoy is designed to accommodate the NexSens X2-SDL submersible data logging system for unattended deployment in lakes, rivers, and coastal waters.

X2-SDL Data Logger

MaterialPVC body with Acetal battery lid
Weight12.0 lbs. without batteries; 16.6 lbs. with batteries
Dimensions5.5” (13.97 cm) diameter; 17.3” (43.94 cm) length (antenna length varies by model)
Power Requirements5-24 VDC +/-15% (Reverse polarity protected)
Current Draw (Typical @ 12VDC)Low power sleep: 200uA; Logger Active: 20mA; Wi-Fi Transmitting: 43mA; Cellular Transmitting: 200mA
Peak CurrentPower supply must be able to sustain a 500mA 1-second peak current (@ 12V)
Operating Temperature-20 to 70°C
RatingSubmersible to 200 ft. (requires SDL-CAP on telemetry models)
Wi-Fi Communications802.11b/g/n (Direct to X2 or Connect X2 to an existing network)
Wi-Fi AntennaInternal to device
Wi-Fi Range250 ft. maximum1
User InterfaceRS-485 direct to PC software, WiFi-Enabled embedded web, WQDatalive Web Datacenter, Magnet trigger for WiFi enable, Status LEDs
Data Logging64MB internal flash*, 256MB microSD card (expandable up to 32GB)
Data ProcessingParameter level polynomial equation adjustment; Basic & Burst Averaging (min, max, standard deviation, and raw data available)
Real Time Clock (RTC)<30sec/month drift2; Auto-sync weekly3; Internal backup battery
Log IntervalUser configurable from 1 second (10 minute default)4; Unique interval per sensor
Transmission TriggerTime-based, parameter threshold*; Selective parameter upload option
Sensor InterfacesSDI-12, RS-232 (3 Channels), RS485
Sensor Power(3) 12V regulated switch channels with 1.5A capacity5,6
Built-in SensorsTemperature (-40C to 85C, 0.002C resolution, ±2C accuracy); Pressure (300 mbar to 1100 mbar, 0.016 mbar resolution, ±2 mbar accuracy); Humidity (0% to 100%, 0.04% resolution, ±5% accuracy); Battery voltage
Sensor Ports(3) 8-Pin for Sensor Interface (RS-232, RS-485, SDI-12, 5V, 12V, GND)
Power Port(1) 6-Pin for Power and Communication (Primary/Secondary/Backup Input, RS-485 Host, GND)

Telemetry Options

CellularCDMA 800,1900MHz, GSM 850, 900, 1800, 1900 MHz, UMTS/HSPA 850, 900, 1700, 1900, 2100 MHz
Radio*900MHz Mesh Network (902-928MHZ Frequency)
Iridium*Short Burst Data (SBD) transceiver
Bridge*Radio to WiFi, Radio to Cellular, and Radio to Iridium
Antenna PortN-Style

Sensor Support

Tier 1Sensors automatically detected; No Setup
Tier 2Sensors automatically detected: Require limited setup
Tier 3*Custom user script creation available for interfacing to a wide array of sensors
Current Sensor ListAvailable Here
  Notes1Range varies based on many factors including obstructions, other wireless signals in the area, elevation change, and more. Actual distances may vary by location. 2Assumes 25°C operating temperature 3Requires the X2 to be connected to the internet 4Minimum log interval dependent on sensor limitations and processing time 5Cumulative concurrent current limit of all three channels is 2A 6Logger power supply must be able to support current requirements of sensors *Coming soon