A debug fixture, also called a defect analysis fixture, is a tool used after airtightness testing to quickly locate leaks in defective products.

Principle: The part of the product to be tested is placed in the debug fixture with an appropriate air gap (observation window). Then, a positive and negative pressure control box is used to pressurize the product internally. The product is then immersed in water, and bubbles are observed. The locations of bubbles indicate leaks.

Alternatively, a vacuum method can be used. The debug fixture containing the product is immersed in red ink, and the product is then disassembled to observe the path of the red ink leakage.