Product Manual (pdf)

Product Introduction

The KH.WQX Pneumatic Bubble Water Level Sensor is a high-precision bubbler-type water level monitoring instrument independently developed by KEHAO for long-term hydrological applications. It measures water level by using a miniature piston pump to inject air into the measuring tube and bubble chamber. The hydrostatic pressure at the submerged point is converted into gas pressure and transmitted through the air tube to the surface. A high-precision pressure sensor then detects and processes the signal to calculate the actual water level with outstanding accuracy, reliability, and long-term stability.

The system adopts imported three-way solenoid valves to effectively eliminate zero drift. The intelligent control unit automatically switches the valve at scheduled intervals for automatic zero-point calibration. Level 1 measurement accuracy is verified within the 0–10 m range, fully meeting national hydrological monitoring standards and engineering application requirements.

Key Features

• Long-Term Stability
  Measures compressed air pressure instead of direct water contact, ensuring stable performance, excellent durability, and reduced sensor aging in harsh environments.
• Easy Installation
  No need to construct stilling wells and not affected by floating debris, sediment, algae growth, or water impurities. Suitable for unattended and remote field installations.
• Automatic Zero Calibration
  Midnight automatic zero correction ensures long-term accuracy and effectively eliminates zero drift and cumulative measurement errors.
• Enhanced Lightning Protection
  Submerged components contain no electronic parts or cables, greatly improving lightning resistance and ensuring safe operation during thunderstorms and extreme weather.
• Temperature Compensation
  Optional external temperature sensor provides automatic temperature compensation to correct density variation effects, improving overall measurement accuracy.
• Flexible Output Interfaces
  Supports analog output and digital communication protocols including RS485, SDI-12, and IoT data transmission for seamless system integration.
• Wide Voltage & Surge Protection
  Built-in protection against reverse polarity, overvoltage, overcurrent, and lightning surge absorption ensures stable and reliable power supply performance.
• User-Friendly Local Display
  Integrated LCD display with keypad enables intuitive real-time water level viewing, configuration, and on-site operation.
• Automatic Tube Cleaning
  Prevents air tube blockage and maintains stable long-term operation in environments with sediment or suspended particles.
• Data Storage Capability
  Supports cyclic storage of up to 10,000 measurement records, convenient for data retrieval and backup.
• Modbus Communication Compatibility
  Fully compatible with mainstream data loggers, telemetry systems, and remote hydrological monitoring platforms.
• Replaceable Air Tube Design
  Modular design simplifies maintenance, reduces service cost, and extends system lifespan.

Application Scenarios

• Continuous monitoring of rivers, reservoirs, streams, canals, and open channels
• National hydrological stations and oceanographic monitoring installations
• Pumping stations, irrigation systems, and hydropower plants
• Flood warning systems, disaster prevention, and water resources management projects

Technical Specifications