Delmhorst’s G-7 Grain Moisture Meter is a highly recommended conductance meter that is one of the easiest meters on the market to use – it requires a very small 3-4g sample and there is no weighing or grinding of the sample necessary. Moisture meters are indirect methods, some meters use capacitance technology, G-7 uses conductance where the meter measures the electrical resistance of the sample when a current is applied between two electrodes.
Other methods (direct) use microwaves or infrared technology. While very accurate, these methods are time-consuming and so not practical for farm and field use.