Innovative Configuration Design of Two-Wire Tip Mechanisms for a Tipping-Bucket Rain Gauge

This paper evaluates the measurement accuracy of the three designs of an innovative Tipping-Bucket Rain Gauge (TBRG) tip mechanism. A water-level detecting circuit is used to replace the conventional reed switch sensor, which addresses the disadvantages of the magnetic sensing method that became a factor in quantification uncertainties. The TBRG configuration designs were the bucket-feed, which detects the presence of water inside the bucket, and the bottom-feed and the center-feed, which use the tip-impact method in measuring rainfall. The constant flow method is used in the experimentation. The bucket-feed shows potential in precision rainfall measurement for having -3.84% and -2.68% accuracy errors at 6 mL/min and 11 mL/min respectively, without correction algorithm applied. The tip-impact application for the bottom-feed and the center-feed resulted in a higher error percentage from the volumetric flow samples. The result indicates that actual detection in the bucket brings more measurement accuracy than the tip-counting technique.