Research on comprehensive environmental tests method of avionics cases under marine environment

Airborne devices that served in South Sea and Eastern South Sea of China failed frequently though they had passed the examinations of relevant military standards. This indicated there were differences between genuine comprehensive environmental tests effect and single environmental tests effect. Therefore, this paper designed comprehensive environmental test method for avionics cases, and by contrasting the conducted humid heat tests and salt fog tests for avionics cases, the advantages of comprehensive environmental tests were researched. Firstly, we designed outdoor tests and transformed environment spectrum to accelerated tests spectrum and designed comprehensive environmental tests. Secondly, we researched correlation analyses methods which included graphical method, chromatic difference analysis, glossiness analysis and property analysis. Thirdly, by conducting surveys on the failure mode and failure characterization parameter which include surface morphology, chromatic aberration, light loss rate, and coating AC impedance, we calculated correlation coefficient with Pearson correlation method and Spearman order correlation method. Finally, by the research on the correlation analyses of atmosphere exposure and comprehensive environment, we obtained the speed ratio of comprehensive environmental tests. Results showed pertinence between humid heat tests and atmosphere exposure tests was poor, pertinence between salt fog tests atmosphere exposure tests was not obvious. As for chromatic aberration, the speed ratio between comprehensive environmental tests and atmosphere exposure tests was 15 to 28, and as for light loss rate, the speed ratio between comprehensive environmental tests and atmosphere exposure tests was 45 to 54, and as for protective performance, 1 day's comprehensive environmental test was equivalent 10 to 15 days' field test. This is of guiding significance for environmental tests.