Application and Practice of Pressure Sensors in Flood Season Water Level Monitoring

During the flood season, water level monitoring is a critical component of urban flood prevention and drainage management. Nexisense pressure sensors, with high accuracy and reliability, play an essential role in rainfall warnings, water accumulation monitoring, and intelligent drainage systems, supporting smart flood prevention. This article discusses measurement principles, advantages, application scenarios, technical specifications, and maintenance methods to provide reference for practitioners.

Overview of Pressure Sensors

Pressure sensors convert pressure signals into electrical signals and are widely used in liquid level measurement. In flood season monitoring, they indirectly measure water levels by detecting liquid static pressure. This method is based on basic physics principles, leveraging the linear relationship between fluid pressure and height to achieve real-time and accurate monitoring.

As urbanization accelerates, traditional manual inspections are inefficient and weather-dependent. With IoT integration, pressure sensors enable remote data transmission and automated control, significantly improving flood prevention efficiency, with response times reduced by over 30% according to industry data.

Methods of Measuring Liquid Level with Pressure Sensors

Pressure sensors primarily rely on Pascal's law to calculate liquid level from static pressure. The formula is P = ρgh, where ρ is fluid density, g is gravitational acceleration, and h is liquid level height.

Common types include:

• Differential Pressure Sensors: Measure the difference between liquid and atmospheric pressure, avoiding atmospheric fluctuations. Suitable for rainwater wells and underground pipes.

• Absolute Pressure Sensors: Measure total pressure and calculate liquid level via algorithms or external compensation. Supports 4-20mA output for PLC system integration.

Installation process: install sensor and connect power → set zero and full-scale → collect and transmit real-time data to the monitoring center. Compared with ultrasonic or radar measurement, pressure sensors are unaffected by foam, vapor, or sludge, making them ideal for turbid flood-season waters.

Advantages of Pressure Sensors

• High Accuracy and Stability: Up to 0.1% FS, reliable under complex hydrological conditions.

• Easy Installation: Compact design allows direct submersion without complex supports.

• Cost-effective: Lower initial investment than laser or radar systems, lower maintenance costs, supports remote monitoring and cloud platform connectivity.

• Durability: 316L stainless steel housing, silicone sealing, IP68 rated, no mechanical parts, reducing failure rates.

• Automation Integration: Can link with pump controllers to automatically regulate water level, improving efficiency and reducing manpower.

Application Scenarios

Rainfall Warning Systems

At urban flood-prone areas such as underground garages or subway entrances, pressure sensors are installed in rainwater wells. When water level exceeds a warning line (e.g., 0.5m), the system triggers alerts via mobile apps or SMS, allowing early evacuation measures.

Intelligent Drainage Control

The monitoring system can adjust drainage equipment in real-time, using tiered control to start pumps based on water level, optimizing energy consumption and avoiding overload. In regions with frequent heavy rain, this application has become standard.

Low-Lying Area Flood Monitoring

Combined with cameras, pressure sensors form a comprehensive monitoring network. Sensors provide accurate water levels, cameras offer visual confirmation, covering critical facilities like pump stations and substations, ensuring safety during floods.

River and Reservoir Monitoring

Continuous monitoring of water level changes. With GPS integration, hydrographs can be plotted to predict flood peaks, aiding upstream reservoir scheduling and downstream flood preparedness.

Technical Specifications

Example: Nexisense NS-P200

• Measurement Range: 0-10mH₂O (0-100kPa)

• Accuracy: ±0.25% FS

• Resolution: 0.01m

• Output: 4-20mA, 0-5V, RS485

• Power Supply: 12-36VDC,<1W

• Protection Rating: IP68

• Operating Temperature: -20°C to 80°C

• Material: 316L stainless steel, corrosion-resistant

• Compensation: Temperature and atmospheric pressure, error<0.1%/10°C

Maintenance and Care

• Check cable connections monthly to avoid wear or looseness.

• Clean sensor surface with soft cloth and neutral detergent; avoid high-pressure washing.

• Quarterly calibration to verify zero and full-scale accuracy.

• Pre-flood season comprehensive testing, simulating high water levels.

• Long-term maintenance: replace seals annually and store in dry environment.

Challenges and Solutions

Challenges include sludge blockage and electromagnetic interference. Solutions: use self-cleaning sensors or integrate filters; multi-sensor fusion (e.g., with ultrasonic) improves data accuracy. Data security supported via encrypted transmission to prevent cyberattacks.

FAQ

• How does a pressure sensor differ from other liquid level methods? Based on static pressure, suitable for enclosed or turbid environments. Ultrasonic is affected by foam; radar is costlier.

• Installation precautions? Measurement end fully submerged, reference end ventilated, avoid cable bending, account for local gravity during calibration.

• Warranty? Standard 2 years, lifetime technical support.

• Can it be used in saltwater? Yes, choose corrosion-resistant models, e.g., titanium alloy housing.

Conclusion

Pressure sensors improve flood prevention efficiency and promote smart water management. Nexisense provides high-precision, reliable solutions covering measurement, installation, and maintenance. With 5G and AI integration, the technology will further optimize urban flood prevention, enabling intelligent flood-season management.