HGUOC Ultrasonic Open Channel Flow Meter

HGUOC Ultrasonic Open channel flow meter contain main unit and sensor, connect sensor to main unit through cable. Sensor detect the liquid level in weir or flume base on the principle of sound wave reflection, then  main unit use the related formula to calculate the liquid volume flow which pass weir or flume.

Ultrasonic Open channel flow meter is non-contact instrument, widely service groundwater flow monitoring system, Industrial wastewater discharge monitoring, accurately measuring open channel flow.

Product Description

  • Non-contact measuring, sensor does not contact the measured medium, without hazard of abrasion and corrosion, long span and easy to maintain
  • High accuracy, liquid level change 1mm, the volume flow will also change correspondingly
  • Suitable for many weir/flume, support international and ISO version of weir/groove, such as Parshall flume, triangular weir (30°, 45°, 60°, 90°, 120°), rectangular weir(can customize weir’s width),can input formula of calculating volume flow.
  • LCD display with backlight, operation language option: Chinese / English
  • Can set flow unit, correct accumulated flow and set many menu item
  • Simple to programming, easy to operate
  • Sensor weather proof grade: IP68
  • Sensor has strong anti-interference performance, low blind area, high sensitivity, the length of cable connecting sensor to main unit can reach to 1000m
  • Can supply 6 relay outputs, pulse output of accumulated flow
  • Can supply RS485 communication base on Modbus-RTU protocol
  • Can supply corresponding manipulator for operate expediently
  • Can customize solar power supply mode, wireless transmission(database server is in China)



principle diagram

Ultra sensor is installed on the top of weir/flume( shown as diagram above), sensor emit a bunch of sound wave to liquid surface periodically, when this bunch of wave reach to liquid surface, it will be reflected back and received by sensor, main unit will measure the transmission time (t) of this process. The known sound wave velocity is “V”.    d=V*t/2,   h=H-d

For the known weir/flume, there is a certain function relationship between the volume flow and the corresponding liquid level value. That is Q= f (h). In main unit, you can set parameter value of weir/flume according to the known weir/flume, the main unit will calculate volume flow automatically during measuring process. Ultrasonic open channel flow meter firstly measures the distance from sensor to the liquid surface, then calculate the liquid level value, then calculate the volume flow. It is important for Installation and commissioning to know this flow meter’s working principle.


Main unit technical data:

main unit Main unit parameter description
Weir/flume type ISO type: Parshall flume (No.1 to 23), rectangular weir(25/50/75/100cm or customize weir width), triangular weir(30°, 45°, 60°, 90°, 120°), customized weir/flume
China National type: Parshall flume (No.1 to 25), rectangular weir (25/50/75/100cm or customize weir width), Right-angled triangle weir, customized weir/flume.
Level resolution 1 mm
Level error 1mm or 0.2%FS @ stable condition
Display LCD display with graph and backlight
Op. Language Chinese / English (can be selected)
Parameter setting Keys operation ( manipulator is option)
Instant flow display range 0.000 – 999999L/S or m3/h, m3/min (automatically conversion base on selected flow unit)
Total flow display Max. value 99999999.9 m3/h
Analog output 4-20mA (corresponding to instant flow)
Load resistance 0-500Ω
Communication RS485 interface, Modbus-RTU protocol
Relay output Upper limit/lower limit alarm (to control instant flow or liquid level)
Pulse output (for accumulated flow, pulse equivalent can be selected)
Relay switch mode Normal open / Normal close (can select)
Relay Number 6 pcs at most
Relay specification 5A  250VAC / 30VDC
Power supply 24VDC (±5%)  0.2A;    220VAC(±20%)  0.1A
Measure cycle 1 second as default (can set)
Ambient Temp. -40 to 75℃
Housing material ABS
Weather proof IP67
Cable gland PG9 / PG11 / PG13.5
Mounting Wall mounted
Size 250*185*125 mm


Sensor technical data:


Sensor parameter description

Level Range 0.00 ~ 4.00 m, 6.00m, 8.00m, 12.00m, 20.00m, 30.00m, 40.00m
Blind area 0.20m
Operation Temp. -40 to 70℃
Weather proof IP68
Shell material Option: ABS / PVC / PTFE
Pressure rating 0.2 Mpa
Cable length Standard configure: 10m, (can extend to 1000m)
Beam angle 8°(3db)
Mounting Thread, Flanged, Bracket


Installation diagram:

installation diagram




Answer : Please send your question or enquiry to our email: sales@hginstrument.com, we will forward the questions to the related engineer.

Answer :  Please communicate with the sales about the return procedure before returning product.

Answer :  The delivery time depends on the order quantity and product specification.  If the product’s specification is conventional ( not special ),  delivery time is 5 or 7 working days for order quantity ≤ 10 pieces;  delivery time is 2 or 3 working weeks for order quantity 15 ~ 30 pieces. 

Answer :  by Courier,  by Sea or by Air

Answer :  Yes,  Generally warranty is one year.

Answer :  From year 2015  to year 2021,  average annual sales is RMB 350 million ( about USD 54.7 million )

Scroll to Top