The manual's bench-work module begins where every good job begins: measurement. You will use the steel rule, tape, try square, scriber, centre punch and spirit level. The rule of the trade is measure twice, cut once — a conduit run marked 5 mm off at the board ends 50 mm off at the far wall. Marking out for electrical work means level lines for switch heights (typically 1.2 m), socket heights (0.3–0.4 m) and straight, plumb conduit runs.