The 10K resistor and the 6 volt battery produce .6mA of current when the probes are crossed to complete the circuit. This meter will detect moisture levels between 0 and approximately 30 kiloohms. Current is the movement of electrons through a conductor. Resistance refers to the holding back of these electrons. Solids, liquids, and gases can all be conductors of electricity.
Water can be one conductor which allows a rapid flow of free electrons.
Dry sand and soil are poor conductors, since they resist the flow of electrons through their particles. The higher the moisture level of a soil sample, the lower its resistance to electrical current. Report any problems, comments or suggestions to the Webmaster . This activity has been accessed times.