The Dynamic Calibration of Tipping-Bucket Raingauges Free

The dynamic calibration of three types of tipping-bucket raingauges extensively used in the Nordic countries was performed. The tested and calibrated gauges were: “LTH gauge”, PLUMATIC gauge and RIMCO gauge. It was found that with regard to all tested gauges, the volume of water which tips the bucket is not a constant characteristic for the gauge; it depends on rainfall intensity. Thus, in order to avoid errors, a calculation of the rainfall intensity or of rainfall volume from tipping-bucket registrations must go through empirical, usually non-linear calibration function. The procedure involved in the dynamic calibration of the tipping-bucket raingauges is described in the paper. Examples of typical calibration curves are provided. The magnitude of errors, in respect of measured rainfall intensity, which occur when linear gauge calibration is used is stated too.