NDT Leak Testing Techniques 3

Question 1

During a hydrostatic leak test, why is it important to vent all air from the system before pressurizing?

Accepted Answer

Trapped air can compress and store energy, creating a potential explosion hazard

Answer

Unlike water, trapped air compresses under pressure and stores energy that can cause a violent failure if a rupture occurs.

Question 2

Which leak testing technique is classified as a 'through-wall' method?

Accepted Answer

Acoustic emission monitoring

Answer

Acoustic emission detects stress waves generated by active leaks passing through the wall of a structure, making it a through-wall technique.

Question 3

What effect does temperature have on pressure decay leak testing results?

Accepted Answer

Temperature increases cause pressure increases, which can mask or simulate leaks

Answer

Per the ideal gas law, rising temperature increases pressure in a sealed system, which can mask actual leaks or simulate false positives during pressure decay tests.

Question 4

What is the purpose of a 'reference leak' in a mass spectrometer leak test setup?

Accepted Answer

To create a controlled baseline for verifying detector sensitivity and calibration

Answer

A reference (calibrated) leak provides a known leak rate to verify that the mass spectrometer system is responding correctly and is properly calibrated.

Question 5

In which industry is the 'bombing' or pressurization method of helium leak testing most commonly used?

Accepted Answer

Aerospace and electronics hermetic package testing

Answer

The helium bombing method is widely used in aerospace and electronics to test hermetically sealed packages for micro-leaks.

NDT - Non-Destructive Testing Practice Test

NDT - Non-Destructive Testing Practice Test

NDT Leak Testing Techniques 3