In Vietnam a municipal water supply project required reliable and continuous liquid level monitoring for multiple underground water storage tanks used in urban distribution networks.

The system plays a critical role in ensuring stable water supply to residential and industrial users. However, due to aging infrastructure and harsh underground environments, traditional level measurement methods were no longer reliable.

A submersible pressure-based level sensor was selected to provide accurate and real-time level data for centralized monitoring and control.

The project faced several operational difficulties:

• Underground water tanks are prone to high humidity and condensation
• Long-term submersion leads to sensor corrosion and signal degradation
• Sediment accumulation affects measurement accuracy
• Water level fluctuations require continuous real-time monitoring
• Maintenance access is difficult and costly
• Conventional float-type sensors fail frequently due to mechanical wear

These issues resulted in unstable level readings and increased maintenance workload.

A submersible level sensor (hydrostatic pressure-based level transmitter) was deployed to replace traditional mechanical and float-based systems.

Key features of the solution include:

• Stainless steel housing for corrosion resistance
• High-precision pressure sensing element for stable level conversion
• IP68 protection rating for long-term underwater operation
• 4–20mA analog output for integration with PLC and SCADA systems
• Anti-clogging design suitable for sediment-prone environments

The sensor measures hydrostatic pressure and converts it into accurate liquid level data for continuous monitoring.

The sensors were installed inside underground water storage tanks located in municipal water distribution stations.

Environmental conditions include:

• Fully submerged operation (continuous water contact)
• High humidity and low oxygen underground environment
• Presence of sediment and suspended particles
• Limited maintenance accessibility
• Long-term continuous operation requirements

The installation was designed for minimal maintenance and long service life.

After deployment, the system achieved significant improvements:

• Stable and continuous level monitoring achieved 24/7
• Measurement accuracy improved to ±0.1% full scale
• Sensor lifespan extended significantly under submerged conditions
• Maintenance frequency reduced by over 50%
• No signal drift or mechanical failure observed during long-term operation
• Improved water distribution system stability and automation efficiency

Overall system reliability was significantly enhanced.

This type of level sensor is widely used in:

• Municipal water supply systems
• Underground water storage tanks
• Wastewater treatment plants
• Industrial liquid storage tanks
• Irrigation and agricultural water systems
• Flood monitoring and drainage systems

Submersible level sensors provide a highly reliable solution for continuous liquid level measurement in harsh and inaccessible environments.

Compared with traditional float or mechanical level switches, they offer:

• Higher accuracy and stability
• No moving mechanical parts (low failure rate)
• Excellent resistance to corrosion and sediment
• Easy integration with modern automation systems
• Reduced long-term maintenance cost

They are an ideal choice for critical infrastructure where uninterrupted level monitoring is required.