- Multi-parameter Water Analyzer
- Single-Parameter Water Aalyzer
- DO Sensor
- Trace DO Sensor
- CO₂ Sensor
- COD Sensor
- EC TDS Sensor
- Salinity EC TDS Sensor
- TSS Sensor
- Turbidity Sensor
- PH Sensor
- ORP
- Ion Selective Sensor
- Ammonia Nitrogen Sensor
- Oil in Water Sensor
- Blue-Green Algae Sensor
- Chlorophyll Sensor
- Residual Chlorine Sensor
- Marine Current Sensor
China Suppliers - Four-Electrode Conductivity EC Sensor Factory for Salinity, TDS, and Water Quality Monitoring
Product Parameters
| Product Name | Four-electrode salinity/conductivity/TDS sensor |
| Range | Conductivity: 0.1~500ms/cm Salinity: 0-500ppt TDS: 0-500ppt |
| Accuracy | Conductivity: ±1.5% Salinity: ±1ppt TDS: 2.5%FS |
| Power | 9-24VDC (Recommend 12 VDC) |
| Material | Polymer Plastic |
| Size | 31mm*140mm |
| Working Temperature | 0-50℃ |
| Cable length | 5m, can be extended according to user need |
| Sensor Interface Supports | RS-485, MODBUS protocol |
Product Features
The innovative four-electrode structure minimizes polarization effects, significantly improving measurement accuracy compared to traditional two-electrode sensors. This design ensures stable performance even in high-conductivity or ion-rich solutions, making it ideal for challenging water quality scenarios.
With a broad range covering conductivity (0.1–500 mS/cm), salinity (0–500 ppt), and TDS (0–500 ppt), the sensor adapts to diverse water types—from pure freshwater to concentrated seawater. Its full-range automatic switching eliminates user error by dynamically adjusting to the detected parameters, ensuring hassle-free operation.
The corrosion-resistant polymer electrode and housing material withstand harsh chemical environments, making the sensor suitable for long-term submerged use in seawater, industrial wastewater, or chemically treated water. The flat surface design reduces biofouling and debris accumulation, simplifying maintenance and ensuring consistent data reliability.
An isolated power supply design mitigates electromagnetic interference, ensuring stable signal transmission and data integrity in electrically noisy industrial settings. This feature is critical for applications requiring continuous monitoring, such as automated process control systems.
Support for the standard MODBUS RTU protocol via RS-485 enables seamless connectivity to a wide range of control systems, PLCs, and data loggers. This compatibility streamlines integration into existing water quality management networks, facilitating real-time data collection and remote monitoring.
Designed for versatile use, the sensor operates effectively in both freshwater and seawater environments, with a compact form factor and G3/4 threaded connections for easy installation in pipelines, tanks, or open-water monitoring stations. Its robust build ensures reliable performance across varying temperatures and pressure conditions.
Application
Seawater Aquaculture & Fisheries Management
Monitors seawater salinity and conductivity in real time to optimize aquaculture environments and prevent salinity fluctuations from harming aquatic life.
Industrial Wastewater Treatment
Tracks ion concentration in wastewater to assist desalination processes and chemical dosing control, ensuring regulatory compliance.
Marine Environmental Monitoring
Deployed long-term in coastal or deep-sea areas to monitor conductivity changes and assess pollution or salinity anomalies.
Food & Pharmaceutical Industries
Controls purity and salinity of process water to ensure product quality and production stability.
Scientific Research & Laboratories
Supports high-precision water analysis for oceanography, environmental science, and data collection in research fields.
Hydroponics and Agriculture
Monitor nutrient solution conductivity in hydroponic systems to optimize fertilizer delivery and irrigation, ensuring balanced plant growth. The sensor’s ease of cleaning and corrosion resistance make it suitable for frequent use in controlled agricultural environments.
Digital RS485 Water Quality Sensors Technical Data
| Parameter | Model | Range | Accuracy |
|---|---|---|---|
| DO sensor | LMS-DO10B | 0-20mg/L, 0-60℃ | ±0.1-0.3mg/L |
| DO sensor | LMS-DO10C | 0-20mg/L, 0-60℃ | ±0.3mg/L |
| Trace DO sensor | LMS-TDO100 | 0-2000ppb, 0-50℃ | ±1ppb |
| PH sensor | LMS-PH100 | 0-14pH | ±0.02pH |
| ORP sensor | LMS-ORP100 | ±1000.0 mV | ±0.2 mV |
| EC/TDS sensor | LMS-TDS102 | CT: 0-9999uS/cm; 0-100mS/cm; TDS: 0-10000ppm |
±2.5%FS |
| Salinity/EC/TDS sensor | LMS-SAL104 | Conductivity: 0.1-500 mS/cm TDS: 0-60000ppm Salinity: 0-500.00ppt |
±1.5%FS |
| COD sensor | LMS-COD100 | COD: 0.1-1500mg/L TOC: 0.1-750mg/L BOD: 0.1-900mg/L Turbidity: 0.1-4000NTU Temperature range: 0-50 ℃ |
±5% equiv.KHP Temperature: ± 0.5 ℃ |
| TSS sensor | LMS-TSS100 | 0-50000mg/L / 0-120000mg/L | ±10%FS or 10 mg/L |
| Turbidity sensor | LMS-TUR10L | 0-100NTU | ±10%FS or 0.3 NTU |
| Turbidity sensor | LMS-TUR10H | 0-3000NTU | ±10%FS or 0.3 NTU |
| CO2 sensor | LMS-CO2100 | 2000PPM/10000PPM/50000PPM | ±5%FS |
| Ammonia Nitrogen sensor | LMS-NH4100 | 0-1000 mg/L | ±5%FS |
| Ion Selective sensor | LMS-ION100 | 0-1000 mg/L | ±5%FS |
| Oil in Water sensor | LMS-OIL100 | 0-50 mg/L ; 0-5 mg/L | ±3%FS |
| Chlorophyll sensor | LMS-CHL100 | 0-500ug/L | ±3%FS |
| Blue-Green Algae sensor | LMS-BGA100 | 0-2000,000 cells/ml | ±3%FS |
| Residual Chlorine sensor | LMS-HCLO100 | 0 - 20.00 ppm | ±5%FS |
| Marine Current sensor | LMS-Current100 | Temperature: -3℃ - 45℃ Velocity of flow: 0-500 cm/s Flow direction: 0-359.9° |
±0.05℃ ±1 cm/s or ±2% ±2° |
Frequently Asked Questions
The four-electrode design effectively eliminates polarization errors and contact resistance. It uses two drive electrodes to establish an electric field and two sensing electrodes to measure the potential, ensuring high accuracy and stability even in high-conductivity, highly saline, or heavily contaminated water environments.
Yes. The sensor directly measures the conductivity of the solution and utilizes built-in mathematical conversion models to calculate and output the corresponding salinity and Total Dissolved Solids (TDS) parameters simultaneously via Modbus communication.
The sensor is equipped with an RS-485 digital interface and supports the standard industrial MODBUS RTU communication protocol. This allows for direct integration with PLCs, RTUs, data acquisition systems, and various environmental monitoring controllers.
Yes. The sensor body is constructed from highly durable polymer plastic materials, offering excellent corrosion resistance. The flat-surface design of the electrodes also reduces biofouling and debris accumulation, making it ideal for continuous, long-term submerged monitoring in seawater or industrial wastewater.
Conductivity measurements are highly temperature-dependent. This sensor features a built-in temperature sensor that provides automatic temperature compensation (ATC) within the range of 0-50°C, ensuring consistent and accurate readings across varying thermal conditions.