A common cause of false positives in tank tightness testing is?

A common cause of false positives in tank tightness testing is?

• A. The tank is actually leaking
• B. Temperature drift during test
• C. Improper sealing at connections or leaks in test apparatus rather than actual tank leaks.
• D. Calibration of equipment

Answer: (C)

False positives show a leak when the tank is actually tight. The most common source is leaks or improper sealing in the test setup itself—improper seals at connections or leaks within the test apparatus. If a hose, fitting, or gasket isn’t sealed properly, air can escape through that path, causing a pressure drop that the test interprets as a tank leak. That makes this option the best answer because it describes a leakage path outside the tank that mimics a leak during testing. A true tank leak would be a real failure, temperature drift or calibration issues can affect readings but are less directly responsible for a spurious indication of a leak in the standard setup.

False positives show a leak when the tank is actually tight. The most common source is leaks or improper sealing in the test setup itself—improper seals at connections or leaks within the test apparatus. If a hose, fitting, or gasket isn’t sealed properly, air can escape through that path, causing a pressure drop that the test interprets as a tank leak. That makes this option the best answer because it describes a leakage path outside the tank that mimics a leak during testing. A true tank leak would be a real failure, temperature drift or calibration issues can affect readings but are less directly responsible for a spurious indication of a leak in the standard setup.