Base Station's Web GUI Configuration

The soil (substrate) VWC, EC, and T Sensor displays the Volumetric Water Content and Pore Water Electrical Conductivity measurements values (Temperature is displayed on the graph).

Under the “Sensors” menu it is possible to select the calibration of the VWC and EC (pore water) calculation method, by selecting Topp G.C., Mineral Soil, Rockwool Ecover, or Rockwool Grodan.

VWC is defined as 6th order polynomial of Epsilon:

VWC = a+b*ε+c*ε²+d*ε³+e*ε⁴+f*ε⁵+g*ε⁶

Where ε is the apparent dielectric permittivity calculated from RAW by

ε = (2.887e-09 * RAW³ – 2.080e-05 * RAW² + 5.276e-02 * RAW – 43.39)² .

Presets based on calibration results

#	Manufacturer	Product	Calibration date	EC (dS/m)	T (°C)	Slab size	Teros-12 placement
1	Grodan	GT Master	2021 May	4.00 (0.02)	22 (2)	H10 x 15 x 17 cm	2x, inserted horizontally, 4 cm from bottom of slab
2	Grodan	Prestige	2021 May	4.00 (0.02)	22 (2)	H7.5 x 17 x 15 cm	2x, inserted horizontally, 4 cm from bottom of slab
3	Ekover	Grunt Tomato	2021 May	4.00 (0.02)	22 (2)	H7 x 20 x 14.5 cm	2x, inserted horizontally, 4 cm from bottom of slab
4	Ekover	Grunt Green 1.0	2021 May	4.00 (0.02)	22 (2)	H7.5x17x20 cm	2x, inserted horizontally, 4 cm from bottom of slab
5	Ekover	Grunt Green 2.0	2021 May	4.00 (0.02)	22 (2)	H7.5x17x20 cm	2x, inserted horizontally, 4 cm from bottom of slab
6	Ozo Golf Club		2021 May	0.25	22 (2)	NA	2x
7	Grodan	DM 32 40/40 HUGO	2021 October	2.1	NA	H14.5x14.5x13.75 cm	2x, inserted horizontally, 7 cm from bottom of slab
8	Charcoir	3 Liter BioPot	2022 April	1.3	NA	16x16x16 cm	2x, inserted horizontally, 1.25 inches from bottom of slab
9	Kekkila	Natural Control	2022 July	4.5	NA	24x12x19 cm	2x, inserted horizontally, 4 cm from bottom of slab

Coefficient values used in presets

#	VWC preset name	6 (g)	5 (f)	4 (e)	3 (d)	2 (c)	1 (b)	0 (a)
1	Topp G.C. et al. (1980)	0	0	0	4.300e-06	-5.500e-04	2.920e-02	-5.300e-02	doi:10.1029/WR016i00 3p00574
2	mineral soil	0	0	-2.925e-08	7.293e-06	-6.845e-04	3.129e-02	-3.612e-02	recommendation by MeterGroup; 0-8 dS/m, 0-60% VWC
3	rockwool Ekover	0	2.070e-09	-5.405e-07	5.443e-05	-2.649e-03	6.858e-02	-4.324e-02	T=22 °C; EC=4 dS/m; Tomato/Green 1.0/Green 2.0; 4 cm from bottom
4	rockwool Grodan	0	0	-7.785e-08	1.756e-05	-1.395e-03	5.224e-02	-5.440e-02	T=22 °C; Prestige/GT Master/DM32 40/40 HUGO
5	coco or peat	0	0	0	0	0	6.276e-03	2.420e-01	30-60% VWC; Charcoir/Kekkila
6	soiless media	-1.655e-10	4.353e-08	-4.473e-06	2.261e-04	-5.812e-03	7.991e-02	-6.141e-02	recommendation by MeterGroup;
	custom	0	0	0	0	0	0	0	write calibration conditions here

If any of the preset calibration values are changed, the method type will be changed to “Custom”.

The graph of soil sensors by default displays Temperature, Volumetric Water Content, and Pore Electrical Conductivity. The thresholds can be set in the sensor’s interface

Use the Tune button (in the Graph section), to display the Bulk Electrical Conductivity and dielectric permittivity (ε).

It is possible to order sensor calibration coefficients for your substrate in SAF Tehnika. Please contact [e-mail] for details.