Chapter 10: Study Guide Summary

Question 1

What can be injected into the system to check for reliability in NDT?

Answer 1

Test items having known discontinuities

These items help verify the effectiveness of the testing process.

Question 2

What is the purpose of periodic unannounced audits in NDT?

Answer 2

To ensure all parameters are under control

Audits help maintain the integrity and reliability of the testing process.

Question 3

What is necessary to establish a schedule of process control?

Answer 3

• Equipment maintenance
• Ketos ring tests
• Meter calibrations

Regular maintenance and testing are crucial for reliable NDT practices.

Question 4

What can happen to inspectors’ alertness after inspecting many parts without detecting a discontinuity?

Answer 4

They may become less alert

Management must be aware of this tendency and select inspection personnel carefully.

Question 5

What is often required for most critical components to ensure reliability?

Answer 5

Reliability demonstration program

This involves using fatigue-cracked specimens with known crack sizes.

Question 6

What percentage of the time were indications with a length of 3 mm (0.12 in.) detected in a typical study?

Answer 6

45 percent

This was determined using over 100 inspectors at a 95 percent confidence level.

Question 7

True or false: Very small discontinuities are always detectable by magnetic particle testing.

Answer 7

FALSE

The probability of detection increases with the size of the discontinuity.

Question 8

What factors can affect the probability of detection in magnetic particle testing?

Answer 8

• Inspectors
• Part processing
• Inspection technique
• Material
• Other factors

The quality of the magnetic field is critical for consistent results.

Question 9

What is the minimum length of an indication that can be detected 90 percent of the time at a 95 percent confidence level?

Answer 9

10 mm (0.39 in.)

Indications must be visually detected, and length is the most important characteristic.

Question 10

What is the goal of reproducibility in nondestructive testing (NDT)?

Answer 10

To provide reproducible testing methods and practices

This ensures that tests yield consistent results across different instances.

Question 11

What is the magnetic particle testing (MT) process used for?

Answer 11

Detecting discontinuities in materials

The ASNT NDT Level III must understand the size and location of detectable discontinuities.

Question 12

Checks for reproducibility must include continuous observation of _______.

Answer 12

detail

Allowing small details to slip can lead to a loss of control in the inspection process.

Question 13

Why is reliability critical in space vehicle components?

Answer 13

Failure of one component can abort an entire mission

Even seemingly insignificant components must be reliable.

Question 14

What human factors affect the reliability of magnetic particle testing?

Answer 14

• Background in materials and fabrication technology
• Knowledge of metallurgy
• Experience in metalworking and manufacturing methods
• Good eyesight
• Conscientiousness

Inspectors must be alert and capable of detecting indications.

Question 15

What practices are encouraged to ensure reproducibility in NDT methods?

Answer 15

• Quality control practices
• Strict adherence to established practices
• Diligence in controlling variables

These practices help maintain consistency in testing outcomes.

Question 16

What should be on file to ensure proper testing technique control?

Answer 16

A method procedure covering each pair or group of similar parts

This ensures consistency in setting up batches for testing.