Theory and Method
IEC 60529 accepts two devices for numerals 3 and 4, and both produce the same water condition by different means. An oscillating tube sweeps a fixed arc around a specimen that rotates beneath it. A hand-held nozzle moves instead, with the operator carrying the spray pattern around the enclosure. The standard treats the two results as equivalent and names the nozzle as the preferred choice when a tube cannot wet every part of the enclosure.
The port pattern does the work. A center hole, an inner ring, and outer rings of ports spread across a spherical face produce a cone of jets rather than a single stream, so water arrives across a spread of angles at once. Flow is set to roughly 10 L/min with delivery pressure held between 50 kPa and 150 kPa, which the gauge at the handle displays. Those two numbers fix the momentum each jet carries when it meets the enclosure.
The shield separates the two test levels. Positioned over the outer ports, it narrows the active pattern so water reaches the specimen only within 60° of vertical, which is the IPX3 condition. Withdrawing the shield opens the full array and lets water arrive from any practicable direction, which is what numeral 4 means by splashing. The counterweight holds the shield steady in either position, so the operator does not fight it while working around a specimen.
