Fig. 1From: Benchmarking electrical methods for rapid estimation of root biomassFour-terminal (4T) sensing of plant–soil system. P1 and P2 are voltage-measuring electrodes. The LCR meter is simplified by an alternating current source, an ammeter A measuring current flowing between C1 and C2 electrodes and a voltmeter V measuring voltage between P1 and P2 electrodes. Phase difference between measured current and measured voltage is also performed by the LCR meter. Three-terminal (3T) sensing used in this study is obtained by merging C1 and P1, and conventional two-terminal (2T) sensing is obtained by additionally merging C2 and P2 Back to article page