%0 Journal Article
%T Differential Measurement for Cavity Ring-Down Spectroscopy with Dynamic Allan Variance
%A Dai
%A Shoujun
%A He
%A Jianguo
%A Liu
%A Yang
%A Mo
%A Zeqiang
%A Wang
%A Jinduo
%A Yu
%A Jin
%J -
%D 2020
%R https://doi.org/10.1155/2020/8398063
%X The method of dynamic Allan variance (DAVAR) is used to analyze the time-varying characteristics of a nonstationary signal and is thus incorporated to evaluate the random error in the cavity ring-down spectroscopy (CRDS) experiments. With the numerical simulation of the influence of instabilities of sudden, slow, or periodic changes on the measurement accuracy in the ring-down process, DAVAR is proved to be an effective way to evaluate random error characteristics in an interfering environment. In order to minimize influences of time-varying noises in CRDS, a practical differential measurement method is proposed, in which wavelength modulation is applied to detect the ring-down times at the absorption peak and the nonabsorption peak in a time-division manner. The validity of the differential measurement is proved with its ability to compensate the influence of the environment changes and improves the accuracy from 0.181£¿ppm to 0.00914£¿ppm. The differential measurement method can be used to correct the time-varying error in real time and is helpful to improve the environmental adaptability of the CRDS instrument
%U https://www.hindawi.com/journals/jspec/2020/8398063/