An Automatic Sequential Rain Sampler

Abstract

A sequential rain sampler has been developed that collects up to 70 samples from 35?70 mm of rain. Each sample has a volume of 500?1000 ml and represents 0.5?1.0 mm of rain. After all bottles are filled, any additional rain is automatically discharged. The area of the collector is 1 square meter. All surfaces touched by the rain water, including the bottles used to contain the samples, are polyethylene or Teflon. After every sample, an event mark is recorded on a strip chart; at the first mark, the chart speed increases from 3.8 cm hr?1 to 3.8 cm min?1. This provides adequate resolution between event marks for the computation of rainfall rate. If a time reference is provided while the chart is on fast speed, the starting and ending times of individual samples are known within 1 sec.