Abstract: To provide guidance for accurate measurement of rainfall in the ecosystem observation and research stations, we conducted field calibration and error analysis of four types of tipping bucket rain gauges by using intelligent peristaltic pump and electronic balance. A regression equation between rotating speed and flow rate was established by adjusting the rotating speed of peristaltic pump, setting the running time, and weighing the pump water. Meanwhile, the peristaltic pump speed under different rain intensities was calculated according to the regression equation and the area of rain gauge. Results of vernier caliper measurement showed that rain ports of the four rain gauges had a certain deformation. The maximum area error rate of rain port of the rain gauges was less than the measurement error requirements of the rain gauges. Under different simulated rainfall intensities, the measurement errors of RG3-M, 6466M, TE525MM and 52203 rain gauges fluctuated greatly, with the error rates ranging from 11.12% to -6.68%, 0.32% to -15.59%, -8.73% to -27.43%, and -16.45% to -34.13%, respectively. The error-rain intensity regression equations were linear or logarithmic, and the fittings were good. The repeatability errors of peristaltic pump were not more than 1.0%, with most of which under 0.6%. Furthermore, the peristaltic pump flow showed characteristic of high stability, good repeatability, and high precision. The rainfall intensity affected the stability of rain gauge measurement, with increasing rainfall intensity tended to weaken the stability. The repeatability limit r values of TE525MM, 6466M, and 52203 rain gauges were less than 1.0% under different rain intensities, meeting the requirements of the national standard for the repeatability limit of rain gauges in China. The repeatability limit r value of RG3-M rain gauge was greater than 1.0%, which could not meet the repeatability requirements. It was a simple and feasible method to use intelligent peristaltic pump and electronic balance to calibrate the tipper rain gauges. The error of rainfall measurement results could be corrected according to the established error-rain intensity fitting equation, which could solve the problem of large error of tipping bucket rain gauge, and thus ensure the accuracy of the observation data of ecosystem research stations.

Key words: ecosystem research station, intelligent peristaltic pump, electronic balance, rainfall.