SPIEA Meteo France direct reading rain gauge

French national meteorological approved rain gauge - Patented SDGGN° 1269277 with direct reading

The rain gauge consists of two interlocking plastic parts and a test tube.

1- The upper part of the rain gauge is opaque, in the shape of a funnel with a perforated bottom, and serves to collect rain over an area of 400 cm², which is very precisely defined thanks to its bevelled edge. The angle of this funnel is designed to reduce the splash of rain outside the reception area to a minimum.

2- The lower part of the rain gauge is transparent, stores the collected water and indicates the height of the rainfall by direct reading on a graduated scale:

• in millimetres for rainfall between 0 and 10 mm with an approximation of 1/4 millimetre
• in centimetres for rainfall between 1 and 10 cm, with an approximation of 1/2 millimetre. This approximation is sufficient for rainfall of this magnitude

3- The rain gauge test tube is graduated in mm and is subdivided into tenths of mm up to 8.2 mm (328cm3). Just below this division there is a small hole of 4 mm diameter so that the excess water collected above 8.2 mm can flow into the bucket. The advantages of installing the test tube in the bucket are fourfold

• reduction of evaporation due to the double wall
• reduction of the evaporating surface of the collected water
• elimination of wetting errors due to decanting
• high measuring accuracy

Legend to the diagram (see illustration) :

1. Funnel with perforated bottom
2. Base for placing the measuring cylinder
3. Measuring cylinder (8.2 mm capacity)
4. Cuvette (100 mm capacity)
5. Rain gauge feet for fixing to a flat surface
6. Visible surface of the steel stand (not sold)
7. Graduation of the cell
8. Test tube holder

Rain gauge supplied with instructions for use.