The core component of infrared detection pool adopts precious metal miniature infrared light source which is high-efficient and long service life. The modulation system adopts high-precision stepper motor control by the micro controller. It is realized that long-term stability of the modulation frequency and infrared pyroelectric solid light cone sensor, Narrowband filters, these instruments make the host in high detect sensitivity, and it is effective way to detect carbon and sulfur content (ppm). it simplifies the hardware design, adding the whole host reliable and anti-interference ability.