The soil water holding capacity was of
20.7% VWC corresponding to measured output voltages of
1.45 V. The temperature sensors were calibrated through a
reference mercury thermometer CT40, with 0.1 °C divisions
and a range from −1 °C to 51 °C. The thermometer and the
temperature sensors were placed in an insulated flask filled
with mineral oil at 10 °C and 40 °C