An inexpensive, portable meter for measuring soil moisture

摘要

Until now, dielectric-based soil moisture measurements required expensive cable testers or commercial systems to read probes. Here we describe a method of constructing an inexpensive meter from a multimeter and a simple power supply. When coupled with a Campbell Scientific (Logan, UT) CS615 probe, the entire system costs $350 US. A single meter can be used to measure multiple probes and the entire system is quite small and portable. The new system reads soil moisture probes capable of measuring a soil's dieclectric constant. Measurements taken with the meter described here and a CR10 data logger recommended by the probe manufacturer did not differ significantly. Nor was there any measurement offset between the data logger and the meter.