1. Problem Background
A hydropower company in southwest China needed to inspect the underwater structures of a 50-year-old concrete dam. The dam had experienced minor leaks and required detailed inspection of its underwater surfaces, including:
- Checking for cracks and erosion on the dam face
- Measuring the thickness of sediment deposits
- Verifying the condition of underwater gates and valves
- Detecting submerged debris that could affect water flow
- Assessing the integrity of underwater reinforcement structures
The inspection team faced challenges with traditional methods, which were time-consuming, required extensive diving operations, and provided limited data accuracy.
2. Problem Analysis
The dam inspection project presented several technical challenges:
- Variable water clarity: Turbid water with visibility less than 2 meters
- Wide depth range: From 3 meters near the surface to 48 meters at maximum depth
- Complex geometry: Irregular surfaces with protruding structures and recesses
- Precision requirements: Need for ±0.5% accuracy to detect small cracks and defects
- Safety concerns: Minimizing diver exposure to high-risk underwater environments
- Data recording: Requirement for detailed documentation of measurements for engineering analysis
Traditional inspection methods using divers with tape measures and cameras were insufficient for this project due to the large area to cover and the need for precise measurements.
3. Solution
The engineering team selected the KWD100 portable ultrasonic depth sounder combined with the KUS-W50 underwater distance sensor to address these challenges. This combination provided:
3.1 System Configuration
| Component | Model | Quantity | Application |
| Portable Ultrasonic Depth Sounder | KWD100 | 2 | Overall depth profiling and general measurement |
| Underwater Distance Sensor | KUS-W50 | 4 | Detailed structural inspection and defect measurement |
| Underwater Camera | Custom | 2 | Visual verification of detected anomalies |
| Data Logger | Custom | 1 | Synchronized data recording with time and position |
| Extension Cables | 30m | 4 | Extending sensor reach to maximum depth |
3.2 Key Product Specifications
| Parameter | KWD100 | KUS-W50 |
| Measurement Range | 0.7-100m | 0.6-100m |
| Accuracy | ±0.5% | ±0.5% |
| Operating Frequency | 200kHz | 200kHz |
| Blind Area | 0.7m | 0.6m |
| Communication | ModBus | RS485 |
| Power Supply | 18650 Li-ion battery | 10.8-26.4V DC |
| Protection Level | IP67 | IP68 |
| Weight | 0.8kg | 0.5kg |
3.3 Implementation Details
The inspection process involved:
- Initial survey: Using KWD100 to create a general depth profile of the entire dam face
- Targeted inspection: Deploying KUS-W50 sensors to measure specific areas of concern
- Data integration: Combining distance measurements with visual data from underwater cameras
- Report generation: Creating detailed engineering reports with measurement data and images
The KWD100 was used for quick, portable measurements from boats and platforms, while the KUS-W50 sensors were deployed on remotely operated vehicles (ROVs) for detailed inspections of specific areas.
4. Results
The inspection project achieved significant results:
4.1 Performance Data
| Measurement Type | Average Error | Maximum Error |
| General Depth Profiling (KWD100) | 0.4% | 0.8% |
| Structural Defect Measurement (KUS-W50) | 0.3% | 0.6% |
| Sediment Thickness Measurement | 0.5% | 0.9% |
| Gate Clearance Measurement | 0.2% | 0.5% |
4.2 Operational Benefits
- Inspection time reduced by 65% compared to traditional diving methods
- Diver exposure minimized with 80% of measurements done remotely
- Data accuracy improved with consistent ±0.5% measurement precision
- Comprehensive documentation with 3,200 measurements taken across 12,000 m² area
- Early detection of 17 previously unknown structural defects requiring attention
5. Conclusion
This solution has since been adopted as a standard inspection method for the company’s dam maintenance program, with plans to expand its use to other water infrastructure projects.
For more technical details, wiring diagrams, or model selection guidance, please click here to learn more or contact our technical team.
