IPX3 and IPX4 with the Oscillating Tube: Angle, Flow and Hole Count

The oscillating tube is the workhorse of IPX3 and IPX4 testing. It produces a fan of jets that sweeps across the enclosure, and the standard defines the geometry so that results are reproducible between laboratories.

Geometry

The tube is a semicircle whose radius matches the enclosure: for small objects a 200 mm radius tube, for larger ones a larger tube that keeps the jets within the specified distance. Holes are spaced 50 mm apart along the arc. IPX3 requires a swing of plus and minus 60 degrees from vertical, IPX4 requires plus and minus 180 degrees, which means the jets pass under the enclosure as well.

Flow rate

Each hole delivers a specified flow, so total flow scales with the number of holes: roughly 0.07 litres per minute per hole, and the test duration is 10 minutes, or 5 minutes per direction where the tube oscillates through a full sweep. If you use a non-standard tube, calculate the flow from the hole count rather than copying a number from another setup.

Practical issues

Keep the tube concentric with the enclosure and at the correct distance; a tube that is too close gives a jet that behaves like a spray. Check for blocked holes before every run, and confirm the oscillation speed, because too fast a sweep reduces the water delivered at any one spot.

Related technical notes

• IPX5 and IPX6 Jet Tests: Nozzle, Pressure and Distance
• IPX7 Immersion: Depth, Duration and the Trapped Air Problem
• IPX8: Continuous Immersion by Agreement