Rain sensor calibration

Introduction

Accurate rainfall measurement is crucial for vineyard management. The databaum rain gauges can provide precise rain measurements when calibrated correctly. This guide is tailored for databaum users who typically use a 0.2mm bucket size.

Installation Check

Before recalibrating, ensure the rain gauge is:

  • Horizontally installed! Otherwise, the values depend on the wind direction.
  • Not obscured by objects like fastening rods, trees, or buildings.
  • Clean the rain gauge to ensure no debris affects the readings.
  • Check your screw color and the setting in the databaum platform as follows.
A red screw denotes 0.2mm
Screw Color Resolution
Blue 0.10 mm
Red 0.20 mm
Green 0.25 mm
Yellow 0.50 mm

Initial Measure Test

To check accuracy:

  1. Precisely measure 500 cm³ (500 ml) of water with a digital scale.
  2. Let the water flow evenly into the gauge over 30 minutes.

If the readings are off, proceed to recalibration.

Recalibration Steps

You can either recalibrate the sensor or do the change via the app. Both has usually the same effect, but if you are off by a lot, please do it via the sensor.

To recalibrate the gauge (sensor):

  1. Locate the hex key screw under the tilting spoon.
  2. Adjust the measurement values:
  • Increase readings: Turn the screw clockwise.
  • Decrease readings: Turn counterclockwise.

To recalibrate via the app:

Just enter the new value in the databaum app. For example 0.195 instead of 0.2.

Testing and Adjustment

After recalibration:

  1. Perform the initial measure test again with 500 cm³ of water.
  2. Readjust the screw as needed until the correct readings are achieved.

Settings

For typical databaum users (0.2mm Bucket Size) (please check the screw color first!):

  • Water per Tipping: 4.0g for a 0.2mm resolution.
  • Tippings for 0.5 Liter: Should be 125 tippings for 0.5 liter.
  • Precipitation Measurement: Should register as 25mm for 0.5 liter.

For other rain sensors, refer to the following table.

Screw color Resolution Water in the cup per tipping Tippings for 0.5 liter Precipitation in mm with 0.5 liter
Blue 0.10 mm 2.0 g 250 25 mm
Red 0.20 mm 4.0 g 125 25 mm
Green 0.25 mm 5.0 g 100 25 mm
Yellow 0.50 mm 10.0 g 50 25 mm
N/A 1.00 mm 20.0 g 25 25 mm