Workshop Practice, Calculation and Documentation
This domain tests workshop organisation, measurement, simple calculations and traceability. The exam expects correct units, clear job records and practical checking before work starts.
Core rules
- Use the WPS, drawing, job card and material certificates together. Check material grade, thickness, consumable batch and welder qualification before welding.
- Measure with the correct tool: steel rule, tape, vernier, micrometer, fillet gauge, square or level. Check zero and avoid parallax.
- Calculate mass from volume and density: mass = length × width × thickness × density. Convert millimetres to metres first when using kg/m³.
- Record welder ID, WPS number, consumable batch, date, joint identification and inspection results.
Worked example
A mild-steel plate is 1.0 m × 0.5 m × 10 mm. Thickness = 0.010 m. Volume = 1.0 × 0.5 × 0.010 = 0.005 m³. Using density 7850 kg/m³, mass = 0.005 × 7850 = 39.25 kg. If steel costs LKR 300/kg, material cost = 39.25 × 300 = LKR 11,775. The reasoning shows why unit conversion prevents a 1000× error.
Traps that cost marks
- Mixing millimetres and metres in a density calculation.
- Using an unqualified welder or unidentified consumable.
- Recording “welded” without the WPS or batch number.
- Measuring with a worn tape and assuming accuracy.