How accurate is a tipping-bucket rain gauge?
The following simulation results shows that the Tipping Bucket estimates suffer from significant errors if based on time scales less than ten to fifteen minutes.

Comparison of Tipping-Bucket Error Statistics:







(Source of above diagrams)


  In this study we attempted to characterize the errors associated
  with tipping-bucket rain gauges when used to provide rainfall
  intensity estimates at small temporal scales. The main source of the
  TB gauge sampling error is its sampling mechanism and its inability
  to capture the small temporal features of the rainfall time series. We
  found significant error levels in the 1-min estimates especially at
  low rain rates, but we also found that as the time scale of the
  computed rain rates increased, the error decreased substantially. With
  time scales longer than 15 min, the error becomes negligible. The
  gauge’s performance and its associated errors are sensitive to the
  applied sampling interval and the bucket volume. Therefore, we
  recommend sampling intervals on the order of 5–10 s, along with a
  bucket size no larger than 0.254 mm (0.01).  Our analysis wasbased on
  rainfall observations that were mostly dominated by convective storms
  with few stratiform events. Similar analysis may be needed to
  investigate the scope of applicability of the developed formulas under
  different climatological regimes. However, the formulas serve as a
  first-order approximation that can be used in practical applications. (Source)