Beijing Jingli Technology CTD Sensor Product Introduction

CTD-xx-mode User Manual

The CTD sensor developed by Beijing Jingli Technology Co., Ltd. is a high-precision measurement device specifically designed for monitoring surface water and shallow groundwater. It can simultaneously collect three key parameters: water depth (pressure), conductivity, and temperature. With a compact structure and stable performance, the device is suitable for various fields including hydrological monitoring, environmental surveys, and industrial applications.

Core Functions and Measurement Principles

• 1. Water Depth Measurement (Pressure Sensor)

  • Principle: Uses a differential pressure sensor to measure the static water pressure generated by the water column, combined with atmospheric pressure compensation (achieved through a Teflon vent), to accurately calculate the actual water depth.

  • Features:

    • Automatically compensates for atmospheric pressure changes; no additional barometric pressure sensor required.

    • The vent uses a waterproof breathable membrane (Teflon material) to prevent liquid water ingress and ensure stable air pressure transmission.

    • Measurement Range: 0-100 meters (optional), Resolution: 1 mm, Accuracy: ±0.25% (at 25°C).

  • Precautions:

    • Avoid long-term operation of the sensor in environments below 0°C to prevent ice damage.

    • During installation, ensure the vent is clear and unobstructed to avoid affecting measurement accuracy.

• 2. Conductivity Measurement (6-Electrode Technology)

  • Principle: Utilizes a 6-electrode AC measurement method, calculating the water's conductivity based on current changes between electrodes, which reflects the Total Dissolved Solids (TDS) content in the water.

  • Features:

    • Automatic Temperature Compensation: Measurement values are automatically corrected to standard values at 25°C, ensuring data comparability.

    • Wide Range: 0-150 dS/m, Resolution: 0.001 dS/m, Accuracy: ±0.01 dS/m or ±10% (whichever is greater).

    • Anti-Interference Design: Electrodes are unreliable for measurement in air; must be fully immersed in liquid for use.

  • Applications: Suitable for saltwater intrusion monitoring, groundwater pollution analysis, wastewater treatment, and other scenarios.

• 3. Temperature Measurement (Contact Resistance Probe)

  • Principle: Detects water temperature through changes in contact resistance, used for temperature correction of conductivity data.

  • Features:

    • Measurement Range: -40°C to +60°C, Resolution: 0.1°C, Accuracy: ±1.0°C.

    • Real-time synchronous output ensures the accuracy of conductivity data.

Product Advantages

High Integration: A single device simultaneously measures water depth, conductivity, and temperature, reducing the cost of deploying multiple sensors.

Low Power Design: Operating current is only 3.5 mA, with sleep mode as low as 2 μA, making it suitable for long-term monitoring.

Multiple Output Interfaces: Supports SDI-12, RS232, RS485, analog voltage, and digital output (DDO), compatible with different data acquisition systems.

Compact and Rugged: Diameter < 3.5 cm, length < 9 cm, suitable for installation in narrow spaces. Constructed with corrosion-resistant materials, it adapts well to harsh environments.

Typical Application Scenarios

Environmental Monitoring: Wetland water level changes, groundwater pollution tracking, saltwater intrusion early warning.

Industrial Applications: Oil exploration (oil layer thickness measurement), wastewater treatment plant water quality monitoring.

Scientific Research: Hydrogeological surveys, laboratory simulation experiments.

Measurement schematic diagram

Technical Parameters Overview