Automatic Field Recording of Vapor Pressure of Soil Moisture with the Pressure Transducer Tensiometer (Automatische Registrierung der Bodenwasserspannung im Gelande mit dem Druckaufnehmer-Tensiometer).

摘要

From testing a pressure transducer-tensiometer for automatic recording of soil-moisture suction in the field the following conclusions were drawn: (1) The resolution is plus or minus 1 cm WS, due to high zero stability and low thermal shift; the response time is very short; (2) Above the soil surface there are no thermal sensitive instrument parts which influence the measuring result; the sensitivity to radiation and to air temperature below 0C therefore is abolished. Furthermore measurements also in greater depths are easily possible; (3) Pressure transducer-tensiometers are particularly suitable to automatic recording of soil-moisture suction in the field, likewise to control of other systems such as irrigation systems. Two examples of soil-moisture suction measurements in a fine to medium sand are given.