Control systems — AC distance, AC vs DC and meter pulses. Shibolet platforms — mixers, pH/EC calibration and maintenance.
The maximum length of an AC cable (from the controller to the field solenoids) depends on several parameters:
Table 1 — voltage drop as a function of cable length (mV drop numbers shown for common solenoids):
| Solenoid | 300m 2×0.75mm² | 100m 2×0.5mm² | 100m 2×2.0mm² |
|---|---|---|---|
| Bermad 2.2 W | 1.60 | 0.80 | 0.40 |
| Bermad 3.3 W | 2.50 | 1.25 | 0.63 |
| Baccara 5.5 W | 3.70 | 1.85 | 0.93 |
| Baccara 8 W | 4.50 | 2.25 | 1.13 |
| Galsol (ECI) | 3.60 | 1.80 | 0.90 |
| Aquanet (Netafim) | 1.00 | 0.50 | 0.25 |
Values are the voltage drop (V) across the cable; source — original Sadot technical table. Always confirm with a site measurement.
The classic question. To answer correctly, several questions must be asked:
In conclusion, there is no absolute answer — the overall system reliability and long-term maintenance must be weighed.
A pulse is a digital / dry contact generated by the meter; the meter closes the contact once per full circle. Common values:
When selecting the right pulse, consider:
In professional fertigation, a mixer blends the fertilizers and acid with water to generate a homogeneous solution. There are 2 types:
Mixing is essential — it is the only way to ensure the sampled solution is homogeneous, so no matter how deep the probe is inserted, it reads the same value.
Before calibrating, compare platform readings against manual readings — run water only and check for deviations.
pH calibration: at the pH/EC interface select pH Factory Setting; for on-site calibration prepare buffers pH-4, pH-7, pH-10 (usually 4–7 range) and select pH 4/7/10 Calibration, following the instructions.
EC calibration: select EC Factory Setting; for on-site calibration prepare the liquid instructed in the EC Calibration option and follow the instructions.