Abstract:
This study aims to create a soil moisture measuring device based on the Wenner
method. The main circuit of the tool uses an IC a type LM 317A with output voltage 1.2
Volts to 37 Volts and can pass current of 1.5 A. The sensor used is a type of cylindrical electrodes with length of 705 mm and the detection electrode consists of a ring electrode with radius equal to 15 mm in diameter and 4 mm thick, spacerring and cone part can be opened. Testing soil moisture measuremen of Inseptisol that taken from UPT Faperta UR, Andisol from Bukittinggi and Entisol from area of watershed Kampar and
measured using the calibrator Soil Tester Lutron produce five levels of soil moisture for each sample. Soil samples with moisture is tested and characterized with a modified 4- point Wenner by injecting a current of 1 mA. these modeling obtained a general
mathematical equation model that describes the relationship between the electrodes
voltage (UO) and soil moisture (θw) on the soil types Uo yo A Tw BTw2 CTw3 the
equation is empirical and has different values for those three soil samples
