The principle of non-dispersive infrared (NDIR) detects the concentration of specific types of gases in the air. It has good selectivity, no oxygen dependence, long life, and no poisoning. IR-Ax series NDIR gas detection module, using excellent performance pyroelectric / thermopile infrared detector, fast response time, the module built-in temperature compensation, at the same time has digital output and analog voltage output, easy to use. The product has the characteristics of high sensitivity, high resolution, and low power consumption. It provides multiple output methods such as UART, analog voltage signal, PWM waveform, etc., with excellent linear output and excellent stability. In response to the needs of different customers for gas detection range, accuracy, size, cost, etc., three platforms A0, A1, and A2 have been developed, which can provide customized development services for customer needs.