关键词: 寄生式时栅, 不确定度分量, 合成不确定度, 评定, GUM规范

Abstract: In order to conduct systemic analyses of the error and uncertainty sources of parasitic time grating sensors, and to improve the measuring accuracy, a 84-level parasitic time grating was used as the research object to establish the uncertainty evaluation system which met the international GUM standard. The angle calculation formula was analyzed according to its measurement principles, and the uncertainty sources were divided into four categories which included errors of interpolation pulses, quantization errors of interpolation pulse signals, periodic errors of traveling wave signals and environmental errors. The theoretical transfer relationship among different uncertainty components were used to deduce the formula for the calculation of the synthetic measurement uncertainty according to the modern uncertainty theory. The experimental platform was built to measure the specific values of the uncertainty components by using the oscilloscope measurement result evaluation. And the synthetic measurement uncertainty of the parasitic time grating sensors was calculated by using the above specific value of the uncertainty components which was compared with the actual sensor measurement errors of the whole circumference. It may be seen that the uncertainty evaluation results by using the above built uncertainty evaluation method are consistent with the actual sensor errors. Therefore, it may be used in the practical evaluation of the parasitic time grating sensors.

Key words: parasitic time grating, uncertainty component, synthetic uncertainty, evaluation, GUM standard