Accurate open channel flow measurement is essential for wastewater management, stormwater monitoring, and regulatory compliance. Applications such as stormwater systems, industrial discharge points, and wastewater treatment channels require monitoring equipment that can perform reliably in challenging field conditions.
TDMA provides complete open channel flow monitoring systems built around Teledyne ISCO flow meters, velocity sensors, and hydraulic measurement devices such as flumes. Our team helps engineers select, install, and maintain the right solution for reliable long-term data collection.
How Open Channel Flow Monitoring Works
Open channel flow monitoring systems measure water moving through partially filled pipes, channels, or natural waterways. Unlike closed pipe systems, the water surface is exposed to the atmosphere, so flow must be calculated using measurements of water level, velocity, or both.
These systems use two main components to determine flow rate.
Primary Measurement Device: Measures physical characteristics of the water such as velocity or water level. These measurements are used to determine the amount of water moving through the channel.
Common primary measurement technologies include:
- Laser velocity sensors
- Submerged area velocity sensors
- Flumes
Water Channel
↓
Primary Measurement Device
(LaserFlow / 350AV / Flume)
↓
Flow Meter
(Signature or DuraTracker)
↓
Flow Calculation
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Data Logging & Compliance Reporting
Flow Meter (Data Logger): The flow meter collects data from the primary measurement device and calculates the total flow rate. It also stores and transmits this data for monitoring, reporting, and regulatory compliance.
TDMA commonly integrates:
- Signature® Flow Meter
- DuraTracker® Flow Meter
Selecting the right primary measurement technology is the most important factor in obtaining accurate flow data.
Choosing the Right Open Channel Measurement Technology
Different monitoring technologies are better suited for different environments. Factors that influence selection include channel type, flow depth, debris levels, installation constraints, and required accuracy.
Quick Technology Selection Guide
| If your application has… | Recommended Technology | Why |
|---|---|---|
| Shallow flow or low water depth | LaserFlow | Non-contact sensor performs well in shallow water conditions |
| High debris or sediment | LaserFlow | Sensor stays above the water, reducing fouling and maintenance |
| Submerged sewer pipe monitoring | 350 Area Velocity Sensor | Designed to measure velocity and depth inside pipes |
| Permanent installation with stable hydraulics | Flume + level sensor | Hydraulic structures provide very accurate long-term measurement |
| Regulatory or compliance monitoring requiring high accuracy | Flume system | Known flow relationships provide highly reliable data |
| Channel cannot be modified | LaserFlow or 350AV | These technologies do not require structural changes |
Detailed Technology Comparison
Below is a comparison of common open channel flow measurement technologies used in municipal and industrial monitoring systems.
| Technology | Installation Type | Accuracy Potential | Maintenance | Best For |
|---|---|---|---|---|
| LaserFlow | Non-contact sensor mounted above channel | Very High | Very Low | Stormwater channels, sewer monitoring, industrial discharge |
| TIENet 350 Area Velocity Sensor | Submerged pipe or channel sensor | High | Moderate | Sewer pipes, wastewater flow studies |
| Flume + Ultrasonic Level Sensor | Permanent hydraulic structure | High | Low | Wastewater plants, irrigation canals |
| Flume + Bubbler Level Sensor | Permanent hydraulic structure | High | Moderate | Dirty or foamy water environments |
| Flume + Radar Level Sensor | Permanent hydraulic structure | High | Very Low | Large channels, rivers, stormwater |
Common Applications
TDMA systems are used across a wide range of open channel monitoring environments, including:
Sewer and Collection Systems: Monitoring combined sewer overflows (CSO), sanitary sewer overflows (SSO), and inflow & infiltration (I&I).
Wastewater Treatment Plants: Tracking influent and effluent flow rates for plant operation and regulatory reporting.
Industrial Discharge Monitoring
Measuring wastewater discharged from industrial facilities to ensure pretreatment compliance.
Stormwater Monitoring
Monitoring storm drains, outfalls, and drainage channels to support municipal stormwater management programs.
Irrigation and Agricultural Systems
Measuring water usage and runoff in irrigation canals and agricultural drainage systems.
Recommended Monitoring Solutions
TDMA integrates industry-leading Teledyne ISCO monitoring equipment with proven measurement technologies to deliver reliable open channel flow monitoring systems.
Signature® Flow Meter
Ideal for: Centralized data logging and compliance reporting.
The Signature® Flow Meter provides comprehensive flow measurement, data logging, and reporting capabilities. It supports multiple flow sensors, including ultrasonic, bubbler, and LaserFlow technologies, and can integrate with pH and temperature modules for complete monitoring solutions. Its advanced logging and telemetry features make it ideal for compliance reporting and long-term monitoring.
DuraTracker® Flow Meter
Ideal for: Long-term field deployment and remote data collection.
The DuraTracker® is a versatile and rugged flow and data logging device, engineered for long-term field deployment. It continuously monitors flow, rainfall, and other critical environmental data points while providing remote access via telemetry. With modular connectivity to ISCO sensors and samplers, it delivers a cost-effective and dependable solution for open channel flow applications.
Teledyne ISCO LaserFlow®
Ideal for: Non-contact flow monitoring in open channels and harsh environments.
The LaserFlow® is a non-contact area velocity flow meter that measures both surface and subsurface velocities using advanced laser Doppler technology. Designed for open channel applications, it provides highly accurate flow data without coming into contact with the water, reducing maintenance and fouling. The LaserFlow is ideal for industrial discharge points, stormwater channels, and sanitary sewer systems. It can also be paired with the Signature® Flow Meter for seamless data collection and analysis.
TIENet® 350 Ex Area Velocity Sensor
Ideal for: Hazardous locations requiring safe and reliable velocity data.
The TIENet® 350 Ex sensor provides accurate velocity and level data in hazardous or explosive environments. Designed for compatibility with the DuraTracker® and Signature® flow meters, it ensures dependable measurements under harsh conditions where safety and reliability are critical.
Open Channel Flow Flumes
Ideal for: Permanent open channel installations requiring accurate, low-maintenance flow measurement.
OpenChannelFlow flumes provide dependable, no-moving-parts flow measurement for wastewater, stormwater, and industrial discharge systems. By shaping and accelerating flow through a precisely engineered throat, each flume converts water level into an accurate flow rate without the need for continuous recalibration.
Available in a variety of styles—including Parshall, Trapezoidal, H/HS/HL, Cutthroat, and RBC (long-throated) flumes—these units can handle a broad range of flow conditions and debris loads while maintaining excellent hydraulic accuracy. Flumes can be constructed from fiberglass (FRP), aluminum, or stainless steel, depending on the site environment.
TDMA integrates these flumes with ISCO monitoring systems such as the LaserFlow, Signature, and DuraTracker for complete open channel flow solutions. Optional accessories like stilling wells, wing walls, and transducer mounts ensure stable, accurate readings even in variable hydraulic conditions.
From product selection to field setup and calibration, TDMA ensures your open channel flow monitoring systems operate at peak performance. Our technicians provide full installation, maintenance, and verification services to help you stay in compliance and eliminate downtime. With continuous support and detailed recordkeeping, we make it easy to maintain reliable flow data and focus on the rest of your operation.
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