Davis+VantagePro2+Rain+Gauge+Calibration+Procedure

Problem
How do I calibrate the VantagePro2 rain gauge?

Solution
54.4 milliliters poured at a steady rate over three minutes should give 10 counts (0.1"), but pouring water through ten times will give ten different results, because it is so hard to simulate falling rain by pouring water into the collector.

If your readings are low, you'll want to raise your calibration screws an equal amount. Each full turn should cause a 6% correction. Document the change you have made from the original factory setting. Compare totals on the next three subsequent storms with a graduated cylinder-type gauge placed right next to the rain collector. Develop an average for how far off the readings are. Then you can readjust the screws to fine tune the reading for the next three storms.

To reference the rain gauge manual for calibration, please visit:

http://www.davisnet.com/product_documents/weather/manuals/Rain_Collector_II_Rev_B.pdf

The calibration procedure is the same for all Davis Instruments rain gauges.