Davis Tipping Bucket Calibration Clarification
Every Davis Vantage Pro2 rain collector has been factory calibrated to measure either:
- 0.01” of rain with each tip for US models (Davis 7345.425 printed on the side of the rain bucket),
- or 0.2 mm of rain with each tip for UK and EU models (Davis 7345.147 printed on the side of the rain bucket).
The ability to use either calibration to accuratly display rain depth in either mm or inches has been verified by Davis Instruments technical support. A tipping bucket calibrated specifically for 0.01” or 0.2 mm, is not relivant as long as your console (or weatherlink live) is properly setup to know what callibration of the rain bucket is installed, and should not be confused with the console’s ability to toggle between inch to mm accuratly once the calibration has been set.
While the console (or weatherlink live) is in setup mode you have the opportunity to specify the calibration of the tipping bucket. By default the rain collector is set to 0.01 IN which corresponds to the Davis 7345.425 tipping bucket which comes default in all USA versions of the Vantage Pro2:
If you purchase a USA version of the pro2 which has the “M” at the end of the model number (for example: 6152M, 6163M, 6153M, 6152CM) the rain collector is calibrated for 0.2 mm instead of 0.01″ and you must change the default rain collector setting on screen 12 from 0.01 IN to 0.2mm by Press the + and – keys to display the 0.2 mm setting then press DONE key to use the selected setting and move to the next screen.
Once the console (or weatherlink live) is set for the rain bucket with matching calibration you may view standard USA units or metric units with equal accuracy.
It is a misconception that a Davis 7345.425 inch calibrated tipping bucket is required to accurately measure rain depth in inches. Likewise it is a misconception that a Davis 7345.147 mm calibrated tipping bucket is required to accurately measure rain depth in mm. It is true that if you have a Davis 7345.425 inch calibrated tipping bucket installed but have your console set for 0.2mm, or if you have a Davis 7345.147 mm calibrated tipping bucket installed but have your console set for 0.01 IN that the readings will not be accurate.
TL;DR Make sure your calibrated tipping bucket matches your console (or weatherlink live) setting for accurately in both inches or mm.