A novel method and system for the fast calibration of tipping bucket rain gauges

摘要

The calibration of tipping bucket rain gauges (TBRs) before installation is an important but very time-consuming task, especially at low rainfall intensities. To address the time consumption, this paper developed a novel method and calibration system to improve the TBR calibration efficiency. Two peristaltic pumps were adopted in this method: one pump provided some simulated rainfall intensities, and another pump provided high rainfall intensities (termed accelerated rainfall intensities) to quickly inject a given amount of water into the TBR bucket before tipping. To verify the feasibility of the novel method, this investigation performed comparison experiments with three different types of TBRs. In addition, various accelerated rainfall intensities and ratios of the injected water volume to the total volume of the bucket were combined to conduct experiments at three simulated rainfall intensities of less than 1 mm min(-1) to obtain the optimal schemes and maximize the timesaving ratio (beta). The results of the comparison experiments demonstrated that the performances of the new and conventional methods were quite close; notably, the average errors differed by less than 0.32%. According to the ANOVA results, all P-values were greater than 0.05, and most were greater than 0.1. Therefore, there was no significant difference between the results of the two methods, verifying the feasibility of the new method. The scheme-based experimental results show that beta can exceed 45% and reach 89%; thus, the novel method can greatly reduce the required calibration time. In summary, the fast calibration method proposed in this work is feasible for solving the time consumption problem and can increase the availability of TBRs in hydrology, meteorology and other sciences.