Kanalis TT MT

Acoustic Multi-Path Flowmeter 

HydroVision‘s Kanalis TT MT is a velocity area open channel ultrasonic flow meter which uses the acoustic „traveltime“ method. This method assumes no relation between level and flow, like weirs or flumes. It will correctly determine water flow throughout its designed range by measuring water velocity and depth. For installation in open channels or closed conduits, Kanalis TT MT operates over the fully bi-directional flow range without causing obstruction or head loss. Onsite characteristics such as varying water levels, skew flow or complex channel shapes are taken into account via specific path configurations.

Typical flowmeter applications include:

Rivers, Irrigation Channels, Industrial Discharges, Sewage Treatment Plants (WWTP), Hydroelectric Power Plants  



  Acoustic Paths   1 – 10 (more upon request)
  Channel Width   up to 20 m  (up to 65 ft.) (more upon request)
  Number of Channels   1 (more upon request)
  Accuracy   < 2,5 % of the reading (under normal flow conditions)
  Keyboard   4 keys
  Display   4 lines, 20 characters
  Datalogger   16 GB Micro SD-card
  Communications   RS485 MODBUS (RS232 or RS485) WLAN GPRS Ethernet 10/100 Mbps
  Inputs   max. 4 x 4-20 mA 2x digital
  Outputs   max. 4 x 4-20 mA 2x digital 4x Relay
  Power Supply   85-260 VAC (48-60 Hz) or 9-36 VDC
  Approval   IP 65
  Enclosure   ABS, wall mounted


    PDF-Logo Kanalis TT MT brochure (PDF) 


TD-200/18, TD-200/8, TD-200/18-ATEX







Frequency    200 kHz    200 kHz    200 kHz
Bandwidth    18° (-3dB)    8° (-3dB)    18° (-3dB)
Dimensions    Ø 140 mm, Height 70 mm    Ø 218 mm, Height 109 mm    Ø 140 mm, Height 70 mm

Mounting Assembly

    Standardized mounting devices for any kind of channel geometry like rectangular, trapezoid or natural river banks are available. The design is flow optimized protecting the transducers against moving objects suspending in the flow stream. It also provides room for connections and protective conduits.



Single-, Crossed- & Multi-path Systems

Single-path system

In its most basic form, the ultrasonic gauge operates with a single pair of transducers.   However, it relies upon a relatively stable velocity profile, essentially unaffected by changes in the relation between water level and flow.   The main flow has to be parallel to the bank. The relationship between measured velocity and discharge is established by hydrometric calibration.   Kanalis TT single path ultrasonic flowmeter for open channels


Crossed-path system

In rivers there is a high risk of cross flow. Its intensity depends mainly on the river’s geometry and if there is an upstream bend in the river.   Although the cross flow does not influence the quantity of the discharge, it may affect the measurement, a second pair of transducers will be necessary.   By crosswise arrangement of four transducers, effects of changing flow direction can be eliminated.   Kanalis TT crosses path ultrasonic flowmeter for open channels


Multi-path system

An even more accurate discharge measurement can be obtained with systems using several planes.   The measured result can be further improved by using a multi path system layering each of the acoustic paths in parallel planes one above the other. This negates having an expensive hydrometric calibration.   This type of system is suitable for applications with large water level fluctuations, reverse flow or a vertical velocity distribution outside the theoretical normal.   Kanalis TT multipath ultrasonic flowmeter for open channels