The substrate sensor measures ECb and ECw.

The sensor measures ECb (Bulk EC) as a raw value. Bulk EC is the electrical conductivity of the bulk soil (soil, water, and air). Sensors installed into the soil all measure bulk EC. The industry standard or what EC usually referenced is ECw (Pore EC), Pore water EC or soil water EC is the electrical conductivity of the water in the soil pores.

To do this tiny sensors would have to be inserted into microscopic water-filled pores. Obviously, it’s not possible to measure the EC of water on that scale. In fact, the only way to measure pore water EC is by extracting a soil water sample and measuring the EC of that sample. We use equations to calculate the pore water EC (ECw), this is done by taking the VWC & ECb values.

Please note that your calibration and VWC figures will impact the ECw output value.

If the VWC is below 25% then the ECw reading is not accurate, so we have chosen not to display this figure on your charts. So if you find breaks in your ECw charts, this is because of the low VWC reading.