SonTek-SL Series SonTek SL500 Side-Looking Doppler Current Meter

Overview Specifications Software & Firmware Industries & Applications Documentation & Tools

Side-Looking Doppler Current Meters

A reliable classic, the SL500 delivers data mid-channel, yet is mounted pier or shore-side for quick access and maintenance, without the use of divers or boats. It is lightweight and easier to mount than comparable systems, yet delivers horizontal ranges up to 120m (400ft). 

Product Features
  • Long-range option for rivers, ports and harbors
  • Sampling range: 1.5 to 120m (5-400 ft)
  • Minimum channel width: 6.5m (21 ft)
  • Acoustics — Vertical Beam Width: 3.8°
  • Lightweight, easier to mount than comparable systems
  • Water velocity, level, and flow
  • Water velocity profiling

Ideal for:

  • Large rivers, estuaries, and large water delivery canals
  • Bridge and pier-side monitoring of tides and currents for port safety, vessel navigation, and weather stations
  • Offshore platforms

Compact, Hydrodynamic Design: Incredibly lightweight and easy to transport and mount. Slim shape is easy to maintain, stays clean, increases available sample area, and fits into more places.

Water Velocity Profiling: Customizable, flexible setup options to suit a variety of applications. 3G models offer 128-cells for high-resolution and detailed profiles.

Versatile, Easy Mounting: Easy-access side mounting reduces concerns over personnel safety, lowers operational cost by avoiding divers and boats, avoids interruption in facility operations, and avoids interruption in data and water delivery to clients and stakeholders.

Wave Spectra Option: Integrated pressure sensor calculates and outputs wave-height and period, in real-time.

Smart Software

Every SonTek-SL comes complete with industry-leading, user-friendly Windows software packages including SonTek’s velocity indexing discharge rating software, FlowPack. Print professional reports easily with the confidence that you will produce consistent, robust results.
An entire rating analysis can be completed in a matter of minutes with automatically developed stage-area relationships and selection of the best-fit velocity index equation. Data can be imported from a variety of resources including SonTek instruments and other devices.




*Actual maximum range depends on environmental conditions.
**Beam width reported at half power level (-3dB).
†Side lobe suppression improves the aspect ratio of the instrument enabling greater measurement range in shallower water.
‡ FS = Full Scale.
§ Power consumption will be higher is Flow Display is enabled.

Software & Firmware

Software & Firmware


For SonTek-SL1500 (3G) and SonTek-SL3000 (3G) models only.  The SonTek-SL Intelligent Flow software is an all-in-one package for interfacing with the 3G models of the SonTek-SL. Interface with the system, do setup, prepare deployment templates, run diagnostics, download data, create graphs and export data, all from the same intuitive software screen.

Learn More   Download

flowpack-screenshot.jpgFLOWPACK SOFTWARE — V 1.21 — 18FEB2013

Become an instant velocity-indexing pro! FlowPack allows you to generate easy to interpret Velocity-Index ratings. Promising to make your data reporting process a whole lot friendlier (and faster), FlowPack also provides a simple method to store flow, velocity, and stage measurements — all through one software program. FlowPack can produce comprehensive reports that assist you in making better, more informed decisions.


viewarg-screenshot.jpgVIEWARGONAUT SOFTWARE — V 3.72 — 29JUL2010

22.35 MBViewArgonaut is a Windows-based deployment, postprocessing, and diagnostic software program that can be used with any SonTek Argonaut current meter (MD, SW, XR, Argonaut-ADV and SonTek-SL500).

SONTEK-SL 3G FIRMWARE — V 3.100 — 06DEC2018

Find the latest version of SonTek-SL 3G Firmware here. Please contact for technical help or questions.


Recent update corrects Modbus Output "Level" Parameter: The Modbus output of the "Level"parameter in Register 30051 & 30052 was corrected to not include the SystemElevation used in the "Stage" parameter and the flow calculations. It is now simply the water level above thevertical beam as intended. The changedoes not affect any other output formats (i.e. SDI-12) or internally recorded data.

Previous udpates include:

  • Adds two new Channel Types (Culvert and Equation)
  • Improved Total Volume calculations; allows accumulating volume even when collection is temporarily interrupted
  • Option added to disable Total Volume Reset on the Flow Display
  • Adds SDI-12 Auto Sampling, which allows instrument to continue data collection even when no data logger command is received
  • Improved low-battery recovery; allows automatic data collection restart if a low-voltage battery recovers (e.g., when battery recharges itself via a solar panel)
  • Adds an alternate method of interrupting data collection via a modem using plus (+) or equals (=) characters
  • Scaling of analog output signals now based on setting of Total Volume units

If you wish to take advantage of the new features in this version, follow the instructions below based on the version of firmware currently in your system.


This is a free update for systems that currently have v7.0 or later firmware installed. We strongly recommend updating your system to this new version. To update your system to this version:

  • Download and install the latest version of SonUtils - v4.20 (or later) for Windows 7/Vista/XP/2K, or v2.50a for Windows 98/95
  • Download and install the latest version of the ViewArgonaut Software program (v3.62 or later).
  • Download the Argonaut SL/SW/XR Firmware v12.0 Update Package - This package includes release notes that explain the new features and how to take advantage of them. It also includes the firmware file, your serial number access code, and instructions for loading the firmware into your system.


Any system with a firmware version before v7.0 would need to be returned to SonTek for a hardware upgrade. There is a fee for the hardware upgrade service. Please contact our Support team for an RMA to upgrade your systems.

Contact Support


Argonaut-MD/SL/XR DOS-based programs used to control operation and to access data.

*Note: Not for use with Argonaut-ADVs.

Industries & Applications

Industries & Applications

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