At the 11th Symposium on Meteorological Observations and Instrumentation we reported the results of a laboratory study of two Geonor vibrating-wire (VW) weighing precipitation gauges. In this paper we report the results of a field analysis of 6 gauges located at the NCAR Marshall field site near Boulder, CO and one gauge located at Norman, OK. Each of the 7 gauges employed 3 VWs, although it is acceptable to use only one or two. The use of 3 wires provides redundancy and, during calibration-verification, the highest accuracy. The Geonor precipitation gauge is the gauge of choice for the U.S. Climate Reference Network (USCRN).

Laboratory and field calibration-verifications were performed from March 2000 through July 2002. The results show that the average accumulation (i.e., depth) in any gauge was, with two exceptions, always within +/-1%, and typically within +/-0.5%, of the accumulation derived from using known metal or water weights over the 0 to 600 mm range of accumulation in the bucket. The two exceptions indicated the need for recalibration of a particular wire. We will describe the calibration-verification methodology and show examples of its application. Comparisons of 1-minute accumulations among the 3-wires in a gauge for various snow events will be shown as well as a comparison of 1-minute rain rates from the gauge at Norman with those obtained from integrating the drop-size distribution of a state-of-the-art disdrometer.