An open path atmospheric composition monitor is designed based on ultraviolet differential absorption technology.Dark current correction and diode response correction are used to improve the detection limit and Savitzky-Golay filter is used to improve the measurement accuracy.The experimental results show that the designed system has the ability to measure NO and NO 2 in real time with reasonable accuracy.The detection limit of the system is about 0.25 ppm for NO and 0.28 ppm for NO 2 .When the ...