FlowTracker2® Handheld-ADV®

What is the FlowTracker2?

The SonTek FlowTracker 2 (FT2) handheld Acoustic Doppler Velocimeter (ADV®) is a wading discharge measurement instrument that is handheld, portable and precise.

We know our users love and trust the technology with the original FlowTracker, but we wanted more! The FlowTracker2 now comes with functional, modernized features such as Bluetooth, GPS, and a large color screen, to name only a few. The enhancements came directly from the evaluation and feedback from hydrologists, researchers, and scientists who have made the FlowTracker their instrument of choice.

Portable. Precise. Practical. 

The real advantage becomes clear from the moment you start to collect data. Each step of the way FT2 guides you along the measurement process with visual prompts and SmartQC audio alerts just in case something important needs your attention. FT2 handheld software is intuitive, easy to navigate, and includes real-time plots of point data, QC parameters, and measurement verticals, giving you everything you need at-a-glance. Get defensible data correctly, the first time, every time, and minimize data handling back at the office.

Whenever, and wherever you need. 

With rugged construction for any climate and multiple display options for both day and night, FT2 goes whenever and wherever you need it to go. This includes: 

  • Natural Streams, Open Channels & Lakes
  • Irrigation Canals
  • Mining Channels
  • Water Treatment
  • Storm Water
  • Weirs / Flumes

FT2 uses SonTek’s tried-and-true ADV technology, vetted for decades by experts across the globe, in hydraulics labs, and wide-ranging field environments. Improved and perfected for FT2, the acoustic-based ADV sensor offers unparalleled accuracy, particularly in low flow, and in the shallowest water of any wading device. 2-D data in the horizontal plane (2D/3D option available) allows the most comprehensive QC and understanding of flow conditions. User calibration is never required, and 24/7 tech support from SonTek and our worldwide team is only a call away.

Still not sure if the FlowTracker2 is right for you? 

Learn more about what makes FT2 a step above the rest! Download the brochure for a complete listing of special features. Or Check out our Manual and select the technology best suited for your flow monitoring requirements! As always, we are here to help if you have questions! 

  • Features
  • Specifications
  • Software

At its core, FT2 uses SonTek’s tried-and-true ADV technology, vetted for decades by experts across the globe, in hydraulics labs and wide-ranging field environments.  Improved and perfected for FT2, the acoustic-based ADV sensor offers unparalleled accuracy, particularly in low flow, and in the shallowest water of any wading device.  2-D data in the horizontal plane (2D/3D option available) allows the most comprehensive QC and understanding about flow conditions.  User calibration is never required, and 24/7 tech support from SonTek and our worldwide team is only a call or click away.

Some of the major improvements now featured in FT2 come straight from field users like you. Here is a short list of time-saving, fool-proof features:

FT2 battery compartment is now
easy to access in the field:
  • Embedded GPS for georeferencing with automatic or manual fixes
  • Improved ADV acoustics: faster pinging, lower noise and better standard error
  • Battery life icon on the screen at all times.  Pre-load the spare cartridge and replace, even mid-measurement, with no data loss
  • Detachable probe with extension cables to customize cable length up to 10m
  • Probes and handhelds are interchangeable—flexibility within agency teams and when sending equipment for service
  • Set up and save templates—no need to re-enter data every time you visit a site
  • Bluetooth or direct USB interface with PC
  • Audio prompts

There is a lot to get excited about when using the new FT2 handheld. Intuitive workflow and rich graphics make for a modernized, interactive experience. Now you can:

  • Rely on FT2 to automatically conform to proper methods based on depth
  • View beam check or QC plots directly - know immediately if you have signal or beam blockage problems
  • Get real-time plots of velocity and other parameters
  • Enter comments and gage heights with any station
  • View a running discharge summary
  • See an image of top-set wading rod
  • View an on-screen tilt sensor
  • Edit data


SmartQCSmartQC is a built-in quality control feature that gives you the added assurance your FlowTracker data is correct. With each measurement, data is compared to a variety of adaptive QC criteria to ensure the best measurement possible.

Probe Specifications
Velocity Range ±0.001 to 4.0 m/s (0.003 to 13 ft/s)
Velocity Resolution 0.0001 m/s (0.0003 ft/s)
Velocity Accuracy +/1% of measured velocity, +/- 0.25cm/s
Acoustic Frequency 10.0 MHz
Sampling Volume Location 10 cm (3.93 in) from the center transducer
Minimum Depth 0.02 m (0.79 in)
Depth Measurement Range 0 to 10m (0 to 32.81ft)
Depth Measurement Resolution 0.001m (0.003ft)
Depth Sensor Accuracy +/- 0.1% of FS (temperature compensated over full operating range)
+/- 0.05% Static (steady-state at 25°C)
Additionally compensated for real-time
water velocity, temperature, salinity, and altitude.
Temperature Sensor Resolution: 0.01° C, Accuracy: 0.1° C
Tilt Sensor Resolution: 0.001°, Accuracy: 1.0° 
Communication Protocol RS-232
Operating/Storage Temperature -20° C to 50° C (-4° F to 122° F)
Probe Head Dimensions (L)13.3 cm (5.22 in)
(W) 6.1 cm (2.39 in)
(H) 2.3 cm (0.90 in)
Standard Cable Length 1.5 m (4.92 ft)
Weight in Air 0.90 kg (1.98 lbs)
Weight in Water 0.30 kg (0.66 lbs)
Handheld Specifications
Input Battery Voltage 8 - 12 VDC
Power Supply 8 X AA Batteries
Battery Life 11 hours continuous use, typical settings1
Power Consumption 1 W (Average)
GPS: H. Position Accuracy Up to 2.5 m (8.2 ft) nominal2
GPS: Frequency L1 (1.575 MHz)
SBAS compensation (WAAS, EGNOS, MSAS, GAGAN)
LCD Resolution 320 X 240 TFT Transmissive
Bluetooth Class 2, Range = 10 m (33 ft) nominal
USB Micro USB, IP-67
Battery Power to Probe 8 - 12 VDC
Data Transfer RS-232
Data Storage 16 GB. Up to 10k discharge measurements
Up to 10 million velocity samples
Operating Temperature Alkaline Batteries: -20° to 45°C (-4°F to 113°F)
NiMH: -20° to 50°C (-4°F to 122°F)
Storage Temperature -30° to 70° C (-22° F to 158° F)3
Waterproof Rating IP-67 (1m submersible)
Handheld Dimensions (L)10.4 cm (4.1 in)
(W) 6.4 cm (2.5 in)
(H) 23.7cm (9.3 in)
Weight in Air 0.75 kg (1.65 lbs)
Weight in Water -0.25 kg (-0.55 lbs)

1Defined as power on with screen on at 100% brightness, ADV sensor pinging 50% of the time, GPS off, and no sleep periods. Actual battery life will vary depending on FT2 settings, manner of use and brand of battery.
2Ideal conditions and settings. GPS data are intended for approximate georeferencing and site ID.
3Remove batteries from FlowTracker2 handheld if storage temperatures exceeds operating temperature of Alkaline and NiMH batteries as stipulated above.

FlowTracker2 Software - PC

Comprehensive tables and time series graphs allow you to visualize and QC data during analysis. Change SmartQC criteria and edit data—yet rest assured the original file will always remain untouched. FT2's open-source JSON file format is ready to be read into any organization's database, and is supported with direct import to Hydstra and WISKI.

FlowTracker2 PC Software FlowTracker2 PC Software

FlowTracker2 Handheld Software

FlowTracker2 — v 1.7 — 06MAR2020

Graph, view, analyze, and edit data collected with the FlowTracker2 instrument, and generate reports using the Windows-based FlowTracker2 software. Station data as well as point measurements can be edited, yet the original data file will always be preserved. View beam checks and perform many other diagnostic and QC checks whose criteria can also be manipulated in software settings. Generate or edit template files in the office which can be uploaded to the FlowTracker instrument and used to save time in the field. Export data to *.CSV format or import the FlowTracker's open-souce JSON files directly to databases.

March 2020 improvements include:

  • Handheld keypad programming modification to prevent accidental and unintended keypad lockup. Recommended for all users.
  • Handheld electronics revision resulting in an expected battery life of approximately 11 hours of continuous use under normal operating conditions.

Recent updates also included:

Handheld Software 

  • Improved work flow and display for under ice measurements
  • Station number now included in title bar at each point measurement so you always know what station you are at and how many you’ve performed
  • The maximum number of templates has been increased to 100 so you can store your entire agency’s site information for quick measurement set-up

Desktop Software 

  • The mean velocity calculation in the discharge summary is now based on Q/A (and not the measured mean of all stations)
  • User can now enter manual temperature and salinity values in the supplemental data
  • Additional valuable information has been added to the discharge summary: beam check plots, start/end time
  • Improved software speed

FlowTracker2 software includes language support for English, Spanish, French, Portuguese, German, Italian, Russian, Chinese (traditional and simplified), Japanese, Korean, Polish, Catalan, Romanian and Greek. A built-in multi-language translator tool can be used to customize software for additional languages and regional terminology.

  • Microsoft Windows 7 or newer
  • 1GHz processor or better (2 GHz recommended)
  • 2GB memory (4GB recommended)
  • 500 MB available disk space (1GB recommended)
  • Monitor capable of 1024x768 resolution, or better
Get FlowTracker 2 Software

Options & Accessories

FlowTracker Bubble Level

Wading Rod and Bubble Level

The SonTek deluxe wading rod, featuring a sturdy grip and bubble level.

FlowTracker2 with optional wading rod

Wading Rod Kit

FlowTracker2 with optional wading rod.


Automated Quality Control in the SonTek FlowTracker - SmartQC

Automated Quality Control in the SonTek FlowTracker

The SonTek FlowTracker was introduced in 2001 with the intention of providing laboratory quality ADV® (acoustic Doppler velocimeter) velocity measurements in a format suitable for wading discharge measurements. Since that time, the FlowTracker has gained widespread support both in the U.S. and overseas as a modern alternative to conventional mechanical current meters...