Basic Structure

• Inner Tube: Holds up to 25 mm of rainfall.
• Outer Cylinder: Collects overflow once the inner tube is full.

Reading the Measurement

1. If rainfall is ≤ 25 mm:
   • Simply read the markings on the inner tube.
2. If rainfall is > 25 mm:
   • Carefully pour the contents of the inner tube into the outer cylinder.
   • Then refill the inner tube from the outer cylinder, measuring in 25 mm increments until all water is measured.
   • Add up the total to get the full rainfall amount.

⚠️ Important Notes

• Do not use kitchen measuring cups or watering cans to test accuracy — they measure volume differently than precipitation gauges.
• Rainfall is measured in depth (mm), not volume (mL), which is why standard fluid measurements won’t match.

🌧️ Getting Accurate Readings in Your Garden

To improve accuracy:

1. Place 3 gauges about 1 meter apart.
2. Let them collect rainfall over 12 or 24 hours.
3. Combine the water from all three into one gauge.
4. Measure the total and divide by 3 to get the mean rainfall.

To read the rain gauge, there are increments of precipitation mms marked on the inner tube as shown

These are correctly marked.