The INIR4-R290 is a user-friendly digital gas sensor designed for R290 refrigerant leakage detection using Non-Dispersive Infra-Red (NDIR) technology. It features factory calibration for up to 2.1% propane with high resolution up to 50 ppm, temperature compensation, and dual-channel operation with full fault diagnostics. The sensor operates at a supply voltage of 3.2 to 5.25 VDC with average current consumption of 32 mA, provides PWM output at 100 Hz with 10-90% duty cycle for 0-2.1% R290 range, and includes serial communication at 38400 baud. With an operating temperature range of -20°C to +60°C, operating humidity of 0-99%, and operating pressure of 60-120 kPa, the INIR4-R290 is ideal for heat pumps, refrigeration systems, chill cabinets, vending machines, and cold storage applications requiring reliable gas leakage detection and compliance with F-gas regulations and the Kigali Amendment.