Installation Guide for Wastewater, Sewage and Partially Filled Pipe Flow Measurement
Correct installation is one of the most important factors affecting open-channel flow measurement.
For an ultrasonic open-channel flow meter, the sensor needs a suitable hydraulic environment to obtain stable velocity and level measurements.
Even when the flowmeter itself is correctly selected, an installation location with excessive turbulence, air bubbles or rapidly changing water flow can affect measurement performance.
1. Choose a Stable Measurement Location
The first step is selecting an appropriate measurement location. Whenever possible, choose a section where the water flows smoothly and continuously.
Avoid installing the sensor immediately after:
- ► Pumps
- ► Sharp bends
- ► Gates
- ► Sudden expansions
- ► Sudden contractions
- ► Waterfalls
- ► Other major flow disturbances
A stable flow profile helps the sensor obtain more representative flow velocity measurements.
2. Avoid Excessive Turbulence
Turbulence is one of the most common reasons for unstable open-channel flow measurements. If the water surface is continuously disturbed, the measured velocity may fluctuate significantly.
A good installation location should have:
- ✔ Relatively uniform flow
- ✔ Stable water level
- ✔ Limited surface turbulence
- ✔ No sudden changes in flow direction
If the available location has strong turbulence, it may be necessary to consider another measurement point.
3. Check the Water Level
Water level is an important parameter in open-channel flow measurement. The flow area changes according to the water level. If the water level becomes too low, the sensor may not be able to obtain a stable measurement.
Before installation, determine:
- ● Minimum water level
- ● Normal water level
- ● Maximum water level
This information should be compared with the selected sensor’s measurement range. For the Lanry DOF6000, the actual installation conditions should be evaluated according to the specific sensor configuration.
4. Check the Channel Geometry
The flow calculation depends on the actual cross-sectional area of the water. Therefore, the channel dimensions need to be measured accurately.
Typical channel types include:
- ◆ Rectangular channels
- ◆ Trapezoidal channels
- ◆ Circular pipes
- ◆ U-shaped channels
- ◆ Custom channel sections
For a rectangular channel, for example, the channel width is an important parameter. For a partially filled circular pipe, both pipe diameter and liquid level need to be considered.
5. Keep the Sensor Properly Positioned
The velocity sensor should be installed in a position where it can accurately detect the moving water. The sensor should be securely mounted and aligned according to the manufacturer’s installation instructions. Loose mounting or incorrect positioning can result in unstable signals.
6. Consider Suspended Solids and Air Bubbles
Wastewater often contains suspended solids and air bubbles. A moderate amount of suspended material may be normal for wastewater measurement. However, excessive air bubbles can interfere with ultrasonic signals. If the measurement point contains a large amount of entrained air, consider moving the sensor to a location with more stable flow.
7. Keep the Sensor Clean
In wastewater applications, the sensor may gradually accumulate: Sludge, Grease, Biological growth, Sediment. Regular inspection and cleaning may therefore be necessary. The required maintenance interval depends on the actual wastewater conditions.
8. Check the Installation Before Commissioning
Before starting measurement, check:
Mechanical Installation: Is the sensor firmly fixed? Is the sensor correctly positioned? Is the cable protected?
Hydraulic Conditions: Is the channel flowing normally? Is the water level within the measurement range? Is there excessive turbulence?
Configuration: Is the channel geometry correct? Are the dimensions correctly entered? Are the measurement units correct?
9. Installation Photos Are Very Useful
When asking for technical support, customers are encouraged to provide photos of the installation location. A useful photo should show: The complete channel or pipe, Upstream conditions, Downstream conditions, Pumps or valves nearby, The proposed sensor location, Water level. With installation photos and basic dimensions, the manufacturer can more easily evaluate whether the location is suitable.
10. Practical Installation Checklist
☐ Full or partially filled condition is clearly identified
☐ Channel dimensions are available
☐ Minimum water level is known
☐ Flow direction is known
☐ Installation location has relatively stable flow
☐ Excessive turbulence is avoided
☐ Sensor is securely mounted
☐ Channel parameters are correctly configured
☐ Sensor surface is clean
☐ Cables are properly protected
Conclusion
Good installation is essential for reliable open-channel flow measurement. If you are planning to install a Lanry DOF6000 open channel flow meter, we recommend providing the channel dimensions, liquid type, water-level range and installation photos before installation.
Lanry can evaluate the proposed measurement location and help determine a suitable installation arrangement.
Post time: Sep-28-2026