NDT Leak Testing Techniques 2

Question 1

Which leak testing method is most appropriate for detecting very small leaks in hermetically sealed electronic packages?

Accepted Answer

Helium mass spectrometer leak testing

Answer

Helium mass spectrometer leak testing is the most sensitive method available and is widely used for hermetically sealed electronic components.

Question 2

In tracer gas leak testing, what property of helium makes it the preferred tracer gas?

Accepted Answer

Low background concentration in air and small atomic size

Answer

Helium's very low natural atmospheric concentration (~5 ppm) and small atomic size allow it to pass through tiny leaks and be detected at very low levels.

Question 3

What does the term 'minimum detectable leak rate' refer to in leak testing?

Accepted Answer

The smallest leak rate that a detector can reliably identify above background noise

Answer

Minimum detectable leak rate is the smallest leak signal that can be distinguished from background noise with acceptable confidence.

Question 4

A pressure decay test shows a steady pressure drop over time. What is the most likely cause?

Accepted Answer

A leak allowing gas to escape the test volume

Answer

Steady pressure decay in a closed system is a primary indicator of a leak allowing gas to escape.

Question 5

Which standard governs leak testing methods for pressure-containing equipment in the United States?

Accepted Answer

ASME Boiler and Pressure Vessel Code Section V

Answer

ASME BPVC Section V, Article 10 specifically addresses leak testing methods for pressure-retaining equipment.

NDT - Non-Destructive Testing Practice Test

NDT - Non-Destructive Testing Practice Test

NDT Leak Testing Techniques 2