The dew recorder records the amount of dew deposited, the amount of which depends on the temperature, humidity, and air movement, as well as the temperature of the receiving surface, which in turn is influenced by its own radiation. A horizontally arranged metal plate serves as the collector. Its effective surface area, including the top and bottom, is 110 cm².
Due to its relatively small volume and low heat capacity, the plate is subject to maximum subcooling compared to the surrounding air and thus also to maximum dew drop. Both the formation of precipitation and the subsequent re-evaporation are recorded. The plate, together with an intermediate thermal insulation, is mounted to one end of a lever, the other end of which carries the recording pin. The lever is located in the middle of a
A wire made of corrosion-resistant, highly elastic bronze is clamped and serves as the axle. Its torsion compensates for the load caused by the rope. This weighs the rope, and the device can be recalibrated with a set of small weights. The full deflection of the pin corresponds to a rope weight of approximately 6 grams. To prevent the recording result from the rope deposited on the lever, a drip-off device is provided. A collecting device below the plate ensures that none of the measured rope weight is lost.
The dew recorder can also be used to record frost, fog, and drizzle. To prevent interference with the recording by gusts, an oil damper is provided. The damper is adjustable, allowing its effectiveness to be easily adapted to the changing conditions of a more or less exposed installation. It can
can be easily closed during transport. The device can be easily disassembled and reassembled. All parts are made of corrosion-resistant material, and the robust construction allows operation even by inexperienced persons.
