- 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
0102030405
RS485 Four-Electrode Conductivity Sensor for Water Quality - China Suppliers & Factory for EC, Salinity, TDS Monitoring
Product Parameters
| Product Name | Four-electrode salinity/conductivity/TDS sensor |
| Range | Conductivity: 0.1~500 mS/cm Salinity: 0–500 ppt TDS: 0–500 ppt |
| Accuracy | Conductivity: ±1.5% Salinity: ±1 ppt TDS: 2.5% FS |
| Power | 9–24 VDC (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
①
Precise Four-Electrode Design
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.
②
Wide Measurement Capability
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.
③
Robust and Durable Construction
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.
④
Stable and Interference-Resistant
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.
⑤
Easy Integration and Communication
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.
⑥
High Environmental Adaptability
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
1Seawater Aquaculture & Fisheries Management
Monitors seawater salinity and conductivity in real time to optimize aquaculture environments and prevent salinity fluctuations from harming aquatic life.
2Industrial Wastewater Treatment
Tracks ion concentration in wastewater to assist desalination processes and chemical dosing control, ensuring regulatory compliance.
3Marine Environmental Monitoring
Deployed long-term in coastal or deep-sea areas to monitor conductivity changes and assess pollution or salinity anomalies.
4Food & Pharmaceutical Industries
Controls purity and salinity of process water to ensure product quality and production stability.
5Scientific Research & Laboratories
Supports high-precision water analysis for oceanography, environmental science, and data collection in research fields.
6Hydroponics 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 | 0–20 mg/L, 0–60℃ | ±0.1–0.3 mg/L |
| DO sensor | LMS-DO10C | 0–20 mg/L, 0–60℃ | ±0.3 mg/L |
| Trace DO sensor | LMS-TDO100 | 0–2000 ppb, 0–50℃ | ±1 ppb |
| PH sensor | LMS-PH100 | 0–14 pH | ±0.02 pH |
| ORP sensor | LMS-ORP100 | ±1000.0 mV | ±0.2 mV |
| EC/TDS sensor | LMS-TDS102 | CT: 0–9999 uS/cm; 0–100 mS/cm; TDS: 0–10000 ppm |
±2.5% FS |
| Salinity/EC/TDS sensor | LMS-SAL104 | Conductivity: 0.1–500 mS/cm TDS: 0–60000 ppm Salinity: 0–500.00 ppt |
±1.5% FS |
| COD sensor | LMS-COD100 | COD: 0.1–1500 mg/L TOC: 0.1–750 mg/L BOD: 0.1–900 mg/L Turbidity: 0.1–4000 NTU Temperature: 0–50℃ |
±5% equiv. KHP Temperature: ±0.5℃ |
| TSS sensor | LMS-TSS100 | 0–50000 mg/L / 0–120000 mg/L | ±10% FS or 10 mg/L |
| Turbidity sensor | LMS-TUR10L | 0–100 NTU | ±10% FS or 0.3 NTU |
| Turbidity sensor | LMS-TUR10H | 0–3000 NTU | ±10% FS or 0.3 NTU |
| CO2 sensor | LMS-CO2100 | 2000 PPM / 10000 PPM / 50000 PPM | ±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 | 0–500 ug/L | ±3% FS |
| Blue-Green Algae sensor | LMS-BGA100 | 0–2,000,000 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 (FAQ)
QWhat is the advantage of a four-electrode design over a two-electrode conductivity sensor?
The four-electrode design separates the current-carrying electrodes from the voltage-sensing electrodes. This eliminates polarization effects that commonly affect two-electrode sensors, resulting in significantly higher measurement accuracy—especially in high-conductivity or ion-rich solutions.
QWhat communication protocol does this sensor support, and how does it connect to a control system?
The sensor supports the MODBUS RTU protocol via an RS-485 interface. This is a widely used industrial standard that allows easy integration with PLCs, data loggers, SCADA systems, and other water quality management platforms.
QCan this sensor be used in both freshwater and seawater environments?
Yes. With a conductivity range of 0.1–500 mS/cm and a salinity range of 0–500 ppt, the sensor is fully capable of operating in freshwater, brackish water, and concentrated seawater environments. Its corrosion-resistant polymer construction ensures durability in marine applications.
QHow long is the cable, and can it be extended for deep-water or remote installations?
The standard cable length is 5 meters. It can be extended according to the user's specific installation requirements, making it suitable for deeper tanks, pipelines, or remote monitoring stations.
QWhat power supply is required, and is the sensor protected against electromagnetic interference?
The sensor operates on a 9–24 VDC supply, with 12 VDC recommended for optimal performance. It features an isolated power supply design that effectively mitigates electromagnetic interference (EMI), ensuring stable and reliable signal output in industrial environments.
QHow should the sensor be maintained, and is it resistant to biofouling?
The sensor's flat surface design minimizes biofouling and debris accumulation, reducing maintenance frequency. Regular rinsing with clean water is recommended after use in high-fouling environments. The corrosion-resistant polymer material ensures long service life with minimal upkeep.