Windscreen acc. to Tretjakov

Tretyakov in 1952 similarly developed on the basis of tests in the wind tunnel, a sign the Nipher.

The wind screnn  according Tretyakov is equipped with vertically arranged in a circle metal slats. The metal blades are movable horizontally and combined tapered at the base of the rain gauge. The individual slats are interconnected by a chain, which has the very good aerodynamic properties.

The draft shield according Tretyakov composed of:

• · Standpipe for the rain gauge
• · frame
• · Metal slats
• · Small parts for assembl

1. Measuring height

The windshield after Tretyakov is for measuring heights:

• 100 cm
• 150 cm and
• 200 cm

 offered.

To install the existing foundations and screws are used in the measurement field.

The windscreen is made of V2A 1475th The life of 10 years can not be guaranteed when used under average meteorological conditions. For use on islands this guarantee can not be given.

2. Structure

2.1. The ring

The windshield after Tretyakov consists of 24, 35 cm long, circularly arranged metal fins. The metal strips are trapezoidal and have a U shape. The windshield is adjustable in height.

The arrangement on the circle having a diameter of 1060 mm is carried out at the same distance by means of slots.

This also enables easy replacement of the metal blade is guaranteed.

The slats are arranged vertically movable. This allows a pendulum motion of the slats depending on the inflow direction and the wind speed with the aim to reduce the turbulence occurring at the rain gauge and thus to increase the collection efficiency.

Structurally there is provided a swivel range of 30 °.

3. Modifications

In the aerodynamic shape of the upper ends of the metal plate was made, as this leads to deposits of snow. The deposition of hard rainfall leads to delayed rainfall measurement when the precipitation is entered by wind in the encoder.

The modified in this way wind shields are used in the offered version for years successfully in precipitation measurement network of CHMI.

The metal strips have been connected at the lower end with a rope V2a. The plastic parts shown are replaced by V2A components.

The cable limits the pendulum movement and increases the rigidity of the system, whereby the metal fins remain at higher wind speeds at the ring and the effectiveness of the overall system .4 increased.

4. Maintenance

To facilitate the maintenance of the rain gauge is an element of the ring is designed foldable. The element is secured with thumbscrews and can be removed without tools.

 5.The Frame

The supports are placed offset in 120º and are tapered at the foundation base. The supports are fixed using the existing foundation on pins.

The supports and all the connecting components are made of V2A. The whole is also height-adjustable on the supports. This allows the system to be re-leveled and the requirements of the measuring point to be adjusted.

 6. Miscellaneous

The windshield can be retrofitted with a holder for an anemometer for correcting the precipitation values