Automated Bubble Detection for a High-Pressure Dip Test Machine

The challenge

In a dip test, each part is pressurised and lowered into a water tank, and a leak shows up as a stream of bubbles. Operators had to watch the tank by eye for every cycle, which is tiring, varies from shift to shift and leaves no record. Small or slow leaks are easy to miss, and ripples, reflections and changing light in the tank make the call harder still.

What we did

We added a CCTV camera looking into the tank and a Raspberry Pi that processes the video during every test. It separates rising bubbles from ripples, splashes and reflections, confirms a leak only when bubbles keep appearing around the part, and makes a pass or fail call for each cycle. Every result is logged, and the decision goes straight to the automated arm that handles the part, so the test runs without someone watching the water.

What we built

• Continuous view of the test tank through a CCTV camera
• Bubbles told apart from ripples, splashes and reflections
• Pass or fail decision for every test cycle
• Every result logged for traceability
• Result passed directly to the automated handling arm
• Low-cost hardware: a Raspberry Pi and a standard CCTV camera