Calcium sensor for water quality, with a measurement range of 0.2 to 40,000 ppm. This highly accurate water quality sensor works in temperatures from 0 to 50°C and pressures up to 2 atm. It’s sensitive, supports online monitoring, and is perfect for rivers, tap water, industrial wastewater, leachate, seawater, mining water, soil, and cement.
Specification
| Ion Concentration |
| Measurement Range |
0.2~40000 ppm |
| Resolution |
0.01 ppm |
| Measurement Accuracy |
±3% FS |
| Temperature |
| Measurement Range |
-10.0 to 110.0 ℃ |
| Resolution |
0.1 ℃ |
| Measurement Accuracy |
±0.5 ℃ |
| Temperature Type |
Thermistor NTC10K |
| Temperature Compensation |
Automatic |
| Data Transmission |
| Interface |
RS-485 |
| Protocol |
MODBUS-RTU communication protocol |
| Other Parameters |
| Working Voltage |
9~27 VDC |
| Dielectric Strength |
2500 Vrms |
| Power Consumption |
Approx. 0.5 W |
| Material |
PPS Solid |
| Installation Method |
3/4 inch front and rear thread |
| Slope |
26±2 mV @ 25°C |
| Repeatability |
±2% |
| Interference Ion |
Pb²⁺, Hg²⁺, Cu²⁺, Ni²⁺ |
| Pressure Range |
0~2 atm |
| Response Time |
≤30 seconds to reach 95% response |
| Storage |
Long-term: dry storage; Short-term: store in calcium ion standard solution |
| Measurement Range |
0.2 ppm~40,000 ppm |
| pH Range |
3~10 pH |
| Output Impedance |
20~50 MΩ |
| Working Temperature |
0~50 ℃ |
| Maintenance & Cleaning |
Clean with deionized water first, then rinse with calcium standard solution |
| Online Monitoring |
Supported |
| Calibration Point |
1 ppm Ca²⁺ |
| Reference Electrode |
Double junction, single liquid junction structure |
| Connector Type |
Terminal |
| Applications |
Rivers, tap water, industrial wastewater, leachate, seawater, mining water, soil, cement, biomedicine, environmental monitoring, fertilizers, calcium ion detection |
Feature

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High Precision Electrodes: The calcium sensor has highly accurate electrodes that do not require any trial solutions, preventing contamination and ensuring more stable and accurate data.
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Easy Installation: Equipped with a G3/4 pipe thread, the sensor is simple to install and helps reduce installation costs.
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RS485 Output: Supports RS485 signal output, making it compatible with various monitoring and control systems.
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Low Power Consumption: The ion sensor operates with a low power consumption of <0.5W, ensuring efficient use of energy.
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High-Quality Cable: The water quality sensor is designed with high-quality, low-noise cables (standard length 5m, customizable), ensuring stable data transmission.
Dimension (Unit: mm)
Wiring Instructions
| Function |
Color |
Description |
| Data Transmission |
Yellow Wire |
RS-485 Communication T/R+ (A) |
| White Wire |
RS-485 Communication T/R− (B) |
| Power Supply |
Red Wire |
DC Power Positive |
| Black Wire |
DC Power Ground |
Application

Tips: How can I solve the problem of inaccurate or non-responsive measurement of the calcium sensor?
If the sensor appears to be measuring inaccurately or not responding at all, there are several things you can try:
- Check the sensor for contamination: Suspended matter, grease or other deposits in the water may affect the sensor's measurement accuracy. Wash the sensor with deionised water to ensure its surface is clean.
- Recalibrate: If measurements deviate from standard values, it may be necessary to recalibrate to ensure the sensor is adapted to the current water quality.
- Check power supply and connections: Ensure that the power supply to the sensor is stable and that there are no problems with the connection to the data logger or control system. A faulty connection may result in abnormal or unresponsive readings.
- Check electrode condition: After prolonged use, the electrodes may become worn or degraded, resulting in inaccurate measurements. Consider replacing the electrodes at this time.