||Comparison of Daily and Weekly Precipitation Sampling Efficiences Using Automatic Collectors.
Schroder, L. J. ;
Linthurst, R. A. ;
Ellson, J. E. ;
Vozzo, S. F. ;
||North Carolina State Univ. at Raleigh.;Corvallis Environmental Research Lab., OR.
Chemical composition ;
Meteorological instruments ;
Chemical analysis ;
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Precipitation samples were collected for approximately 90 daily and 50 weekly sampling periods at Finley Farm, near Raleigh, NC from August 1981 through October 1982. Ten wet-deposition samplers were used. Four samplers were operated for daily sampling, and 6 samplers were operated for weekly-sampling periods. The design was used to determine if: (1) collection efficiencies of precipitation are affected by small distances between the Universal precipitation gage and collector; (2) measurable evaporation loss occurs and (3) pH and specific conductance of precipitation vary significantly within small distances. Average collection efficiencies were 97% for weekly sampling periods compared with the rain gage. Collection efficiencies were examined by seasons and precipitation volume. Neither factor significantly affected collection efficiency. No evaporation loss was found by comparing daily sampling to weekly sampling at the collection site, which was classified as a subtropical climate. Correlation coefficients for pH and specific conductance of daily samples ranged from 0.83 to 0.99.