In water ingress tests (IP protection rating tests), the oscillating tube and the drip box are two key equipment for IPX1 to IPX4 testing. Under the IEC 60529 standard, the nozzle diameter on both the oscillating tube and the drip chamber measures just 0.4mm. Such a fine needle nozzle naturally faces a practical challenge: the nozzle is easily clogged by impurities and scale in the water, which directly undermines test accuracy and shortens equipment life.
So how can effectively lower the risk of nozzle clogging? Pego has built a complete anti-clogging solution that runs from water source, filtration, air-drying, and unclogging to replacement. This article walks you through each layer.
The first step in avoiding risk starts with the water source. The IEC 60529 standard requires test water to be Fresh water, as opposed to seawater. Tap water, river water, lake water, and deionized water all qualify as fresh water. Among them, tap water is the easiest to obtain, so most customers choose it as their first pick.
However, it should note that water quality varies by region. In some areas, using tap water directly tends to clog nozzles and accelerates scale buildup. For this reason, we recommend purified water as the test water. Of course, for open waterproof testing scenarios, long-term use of purified water proves too costly, and tap water remains the more realistic choice — which is exactly why our follow-up design steps need to back it up.
Since most customers cannot run entirely on purified water, Pego equips its devices with a built-in water purifier as standard. The tap water flows through the water circuit into the purifier, which filters out impurities before the water enters the testing stage, effectively removing particles such as sand and sediment. The equipment uses a 10-inch (Φ60mm×L254mm) PP cotton filter element with a filtration precision of 1 micron. Users only need to replace the filter element regularly, and they can significantly cut the risk of clogging from impurities.
Beyond impurities, residual water left in the circuit after testing becomes a breeding ground for scale — and scale is another culprit behind nozzle clogging. To address this, Pego adopts a vacuum design on the drip box. After the test finishes, users can connect an air compressor to air-dry the pipes and thoroughly drain excess water from the drip box, suppressing scale growth at the physical level. Even so, some nozzles may still clog occasionally, which is precisely why our accompanying tools exist.
For nozzles that have already clogged, Pego equips every device with a stainless steel cleaning needle tool as standard. To use it, simply insert the needle gently into the nozzle and move it back and forth. This effectively unclogs the nozzle with ease.
When many nozzles clog and cleaning proves ineffective, direct replacement is the safest route. Pego has given full thought to ease of replacement in the nozzle design — each device comes with 100 spare needle nozzles, so users can simply swap them in and continue testing. One important reminder: when many nozzles clog, replace them promptly to prevent water pressure from cracking the drip box.
Nozzle clogging can never be entirely avoided, but Pego has done everything possible in design and supporting tools to reduce the risk — from water source optimization, 1-micron filtration, and vacuum air-drying to cleaning-needle unclogging and spare needle nozzles. These five measures form layer upon layer of protection, all aimed at keeping your testing stable, accurate, and efficient.