DFRobot Gravity Lab Grade Analog Electrical Conductivity Sensor Meter V2 K1 - BNC Probe, 0-20ms/cm

The sensor provides a 0-3.4V analog output signal. Connect the sensor's Gravity interface (VCC, GND, SIG) to your Arduino's corresponding 5V/3.3V, GND, and an analog input pin (e.g., A0). The BNC probe connects separately to the module. Use the provided DFRobot library to read the analog voltage and convert it to conductivity values in ms/cm.

Calibration uses a two-point method with standard conductivity buffer solutions. The included software library can automatically identify common standard buffers (e.g., 1413μS/cm, 12.88mS/cm). Follow the library instructions to immerse the probe in the first standard solution, run the calibration command, then repeat with the second standard. The library integrates temperature compensation automatically during measurement.

The AC (alternating current) excitation source is crucial for conductivity measurement to minimize electrode polarization. A DC signal would cause ions to accumulate on the electrode surfaces, creating a counter-voltage that drifts and reduces accuracy. The AC signal constantly reverses direction, preventing this buildup and ensuring stable, precise readings over time, thereby also extending the probe's operational life.

Yes, the sensor supports a wide voltage input range of 3.0V to 5.0V DC. This makes it fully compatible with both 5V systems (like most Arduinos) and 3.3V logic microcontrollers such as the Raspberry Pi, ESP32, or STM32 boards. Ensure your power supply provides a clean voltage within this range for optimal performance.