EvaporimeterThe evaporimeter FAR503AA consists of a pan and wooden platform built according to the WMO standards for class "A" evaporimeters. The pan, made of stainless steel, contains a stilling well in wich is placed the evaporimeter sensor. The sensor type is a floating one, based on a linear pontentiomer. Variations of the water level inside the pan are reflected in the same in the stilling well, causing the lowering (or the elevation) of the float. The stilling well is needed in order to avoid false level variations due to the ripples of the water surface caused by the wind.
The movement of the float inside the well generates a variation of resistance which is transformed by means of an electronic circuit into an electrical output signal.
The pan is placed onto a wooden frame with the upper surface painted white (to minimize solar radiation absorption) and the lower one black (in order to maintain the water temperatures as close as possible to the ground temperature).