Reply to Comments: A Novel Low-Cost Instrumentation System for Measuring the Water Content and Apparent Electrical Conductivity of Soils, Sensors, 15, 25546–25563

Abstract

In this article we respond to the comments made by Chavanne et al., who have questioned: (i) the name of the technique used; (ii) the ability of the system to determine both soil water content and salinity due to potential instrument biases and choice of sensor frequencies; and (iii) the procedure used to determine temperature effect on readings presented in the article “A Novel Low-Cost Instrumentation System for Measuring the Water Content and Apparent Electrical Conductivity of Soils” (Sensors 2015, 15, 25546–25563). We have carefully analyzed the arguments in the comment, and have concluded that they only partially affect the previous conclusions, as will be discussed in this reply. We show here that the findings and conclusions previously drawn are valid and supported by the many experiments previously conducted.

Capacitive Impedance Measurement: Dual-frequency Approach

“…In Reference [28], we reviewed the methods for measuring impedance at low frequency (up to the MHz band) and classified them into three categories: Current-to-voltage (or I-V), bridge, or resonant methods. The I-V method is very simple, however with low accuracy.…”

“…However, Chavanne et al [9] questioned the system’s ability to separately measure σ and ε of the medium under test if the conductivity is greater than 70 μS/cm, since the frequencies used were very low (100 kHz and 5 MHz). In Reference [28], we proposed increasing the frequency of the system using the same electronic design presented in Reference [2], but with a higher speed microcontroller.…”