Abstract: | In this paper,a weak fiber Bragg grating (WFBG) based sensing system applied to the cryogenic static test of launch vehicle oxygen tanks has been developed and the results of an evaluation are reported.A customized sensor encapsulation and installation method allow for precise strain measurement at cryogenic temperatures.The reflection peaks of series-connected WFBGs with low optical loss are obtained,ensuring high system reliability in harsh environments.The experimental results show that the maximum full-scale error is less than 0.81% full-scale error.The temperature is as low as-193 ℃ during the test.This study also demonstrates a practical method in which WFBG can be used to obtain critical parameters for structural monitoring in a cryogenic environment. |