Correlation analysis between fault frequency and service time of underground fluid instruments

In this paper, we make a statistical analysis of the fault information of the underground fluid instruments of 12 models in China from January 2021 to May 2022 based on the Pearson correlation coefficient, and compare the fault statistics of the meteorological three-element instruments of 3 models during the study period. The results show that: (1) The numbers of faults of the underground fluid instruments of 12 models with different service times are basically positively correlated with the numbers of the corresponding instruments, with good consistency. Moreover, the automatic observation instruments (8 models) with more than 30 units are significantly correlated at a 0.05 significance level (95% confidence level). Even at a 0.01 significance level (99% confidence level), there are 7 models (7/8) with significant correlation. (2) The positive and negative correlations between the monthly average number of faults and the corresponding service times of the underground fluid instruments of 12 models with different service times are random, and there are 9 models (75%) with no significant correlation at a 0.05 significance level (95% confidence level), while 12 models (100%) with no significant correlation at a 0.01 significance level (99% confidence level). (3) The monthly average numbers of faults of the underground fluid instruments of 12 models are basically 0.02–0.05 times/(unit·month), and the overall fault frequency is low. (4) The fault statistics results of the meteorological three-element instruments of 3 models are consistent with the characteristics of the underground fluid instruments of 12 models. In general, there is no significant correlation between the fault frequency and the service time of underground fluid instruments. (5) The results of this paper demonstrate that the service time of underground fluid instruments cannot be taken as the main reason for whether to update the instruments. Similarly, the fault frequency of the instruments cannot be taken as the main reason for the service life of the instruments in the process of formulating the service life standards of underground fluid instruments.