Practical Skills, Field Demonstration and Project Work
What the exam tests
This domain tests field measurement, layout marking, installation checks, field performance tests and project record keeping.
Core rules and concepts
- Begin with a site survey: field dimensions, slope, soil, crop spacing, water source, power supply and access.
- Mark head-unit position, main and submain routes, lateral spacing and emitter positions before digging or laying pipe.
- Install in sequence: head unit, mains, submains, flush, laterals, emitters, pressure test and final flush.
- Field tests include pressure at head and farthest point, emitter flow measurement and emission uniformity calculation.
- A simple flow test uses a measuring jar and stopwatch: flow (L/h) = volume (L) × 3600 ÷ time (s).
- Project records should include layout sketch, bill of materials, installation dates, test results and maintenance schedule.
Worked example
A field is 60 m long and 36 m wide. Area = 2,160 m² = 0.216 ha. Rows are 1.2 m apart across the width, so number of rows = 36 ÷ 1.2 = 30. Plants are 0.5 m apart along the row, so plants per row = 60 ÷ 0.5 = 120. Total plants = 30 × 120 = 3,600. With two 2 L/h drippers per plant, total flow = 3,600 × 2 × 2 = 14,400 L/h = 14.4 m³/h. The reasoning is to calculate area, plant population and flow before selecting the pump and filter; reversing the order often produces an oversized or undersized head unit.
Traps that cost marks
- Installing emitters before flushing the laterals.
- Measuring flow at only one emitter and calling it the field average.
- Forgetting to record pressure at the farthest point.
- Mixing units: m² to ha requires dividing by 10,000.
- Leaving the field without a layout sketch and maintenance schedule.