Bowen Ratio

Bowen Ratio Energy Balance (BREB) system is in principle a meterological station completed with one more air temperature/humidity sensor and with net radiation sensor. It is based on the theory of turbulent diffusion with all its limits. However, if the user is aware of those limits, the BREB system gives useful results of real evapotranspiration incomparably cheaper than sophisticated eddy covariance equipment. The real arrangement depends on the height of the canopy and the available budget. When measuring on higher canopies we recommend installing temperature /humidity sensors in three levels for more reliable data:

bowen  3levels
ET and Bowen ratio calculated from sensors at three levels.
Note the increase of Bowen ratio followed by downtrend of evapotranspiration in the afternoon.

Tripod

There are two methods we use for fixing the pole – anchoring and tripods. The design of our tripod is quite robust but adjustable ± 15 deg. The main pole 50 mm in diameter holds cross-arms and all other necessary accessories..

Anchors

Anchoring should be used in a harsh terrain – slope, with strong winds etc. The system we use is long time well-tried and fits even to rocky ground, for instance.

Radiation shield

We manufacture many types of radiation shields which differ in number and type of plates and with holders. They fits to both air temperature/humidity sensors and logging sensors Minikin. The plates are made from aluminum painted by baking varnish which do not tend to yellowing.