Testing the rain gauge 

The accuracy of the rain gauge can be tested by checking the spoon/rocker 

Clean the rain mechanism with water and wipe away an dirt/debris

Check that the rain spoon/rocker moves easily, tip back and worth a couple of times.
Align the rain mechanism horizontally

Quick test with the injection

For this test you need: an injection syringe with at least 4mL capacity, a measuring cup with precise graduation in mL (typical glass measuring cup for cooking), a plastic bottle 

Add 4 ml of water to the syringe and let it drop as far as possible into the middle of the mechanissmus. 

When 4 ml is added to a spoon, the mechanisms should tip over to the other side

Testing the weather station

If the spoon mechanism tips once, then the station should show 0.2mm of precipitation in FieldClimate.

To see if the station is recording the correct value, the spoon mechanisms should be tipped 10 times (40ml of water), which corresponds to 2mm of precipitation.

Test of the rain gauge for large rainfall amounts:

- you need a plastic bottle 500mL

Drill a 1 to 1.5mm (small) hole into the bottom of the bottle, fill the bottle with exactly 500mL of water and place into the rain gauge. If the hole in the bottom of the bottle is to large, then the tipping mechanism will dismiss some readings because the rate is too fast.

The water should flow slowly from the bottom of the bottle. When the bottle is empty, the spoon mechanism should have tipped 125 times, and the station will show 25mm of precipitation in FieldClimate

see also
Test of the rain gauge with OHMmeter

Click HERE for the article Test of the rain gauge with OHM-Meter