DFRobot Gravity HCL Sensor (Calibrated) - I2C & UART

This module is specifically calibrated for Hydrogen Chloride (HCl) gas detection. The electrochemical sensing element is gas-specific; it cannot accurately measure other gases like CO, O2, or NH3 without replacing the probe and recalibrating the system.

Use the included Gravity cable to connect the module's PH2.0-4P port to a compatible shield or adapter. For I2C, connect SDA, SCL, VCC (3.3V/5V), and GND. For UART, connect TX, RX, VCC, and GND. The analog output provides a 0-3V signal proportional to gas concentration. DFRobot provides sample code for both protocols.

The electrochemical sensor has a typical operational lifespan of over two years in normal air. It comes factory-calibrated, but for critical applications, periodic recalibration (e.g., annually) using a known standard gas concentration is recommended to maintain long-term accuracy.

Yes. The module supports 32 software-configurable I2C addresses. You must change the address for each sensor via the provided library commands before connecting them to the same SDA/SCL lines to prevent address conflicts.

The sensor operates reliably within a temperature range of -20°C to +50°C and a humidity range of 15% to 90% RH (non-condensing). Exposure to condensing humidity, extreme temperatures outside this range, or high concentrations of interfering gases can damage the sensing element or provide inaccurate readings.