Read ECH20 10HS FAQs

They are technically not the same. For the strictest technical accuracy, FDR makes a frequency scan and capacitance measures the charge time of a capacitor. From a practical standpoint there is little difference in the performance.

There are two elements to the accuracy of time-domain reflectometry (TDR), frequency domain reflectometry (FDR), and capacitance sensors:

1. How well the sensors measure the dielectric permittivity of the soil; and
2. How well the calibration converts that measurement to water content.

Due to inherent variability in soil physical properties, it is impossible for a dielectric sensor to measure within 1% water content accuracy across a broad range of soil types, even with a perfect measurement of dielectric permittivity. Beware sensors that claim an unbelievable accuracy in all substrates.