Chapter 11: Study Guide Summary

Question 1

What is necessary for the magnetic particle testing process to be reliable?

Answer 1

Adequate maintenance, monitoring, and control of equipment

The process can be broken down into various system variables that must be evaluated separately.

Question 2

List the variables of the magnetic particle testing system.

Answer 2

• Electrical system and controls
• Mechanical components
• Instrumentation
• Suspension vehicle
• Magnetic particles and bath
• Ultraviolet lights

Each variable must be evaluated to ensure the reliability of the testing process.

Question 3

All equipment checks and calibrations must be conducted in accordance with ASTM E 1444 / E 1444 M or as specified in what?

Answer 3

Contract or purchase order

Regular evaluation of data from magnetic particle testing checks is essential to observe trends.

Question 4

What must all calibrations be traceable to?

Answer 4

National Institute of Standards and Technology

Certification of calibration must be available for review.

Question 5

What are the nationally recognized calibration specifications mentioned?

Answer 5

• ANSI Z540
• ISO 10012

These specifications guide the calibration process.

Question 6

What does the electrical system and controls consist of?

Answer 6

• Maximum unit output
• Short test
• Ammeter check
• Quick break test
• System performance check
• Other machine checks

These checks ensure the proper functioning of the electrical system.

Question 7

How is the maximum output of the unit’s electrical system checked?

Answer 7

By placing a copper or aluminum bar between the contacts with the current control set at maximum output

The ammeter should show the maximum amperes capable of being produced by the unit.

Question 8

True or false: The maximum output test should be performed daily.

Answer 8

TRUE

Results should be compared to the certified/calibrated output of the unit.

Question 9

What indicates a shorted electrical system during the short test?

Answer 9

Any movement of the ammeter pointer

This test should also be performed daily.

Question 10

What should the ammeter readings be within during the ammeter check?

Answer 10

±10 percent or other contractually specified values

This ensures that readings are accurate.

Question 11

How often should the shunt/ammeter and unit ammeter be calibrated?

Answer 11

At least every six months or as otherwise specified

Both readings must be recorded.

Question 12

What is the purpose of the quick break test?

Answer 12

To determine if the quick break circuit on the coil is functioning properly

This test should be conducted at least once every six months.

Question 13

How often should the Shot Timer Check be performed?

Answer 13

At least once every six months

The timer must be calibrated at least every six months with a device measuring to at least ±0.1 s accuracy.

Question 14

What is the minimum duration of current flow for each magnetizing shot?

Answer 14

At least 0.5 s

The maximum duration is 1 s to prevent parts from burning.

Question 15

What test is used to show that the system is functioning properly and has sufficient sensitivity?

Answer 15

Ketos ring test

This test was first required by MIL-I-6868 in 1972.

Question 16

What diameter range must the nonferromagnetic central conductor be for the Ketos ring test?

Answer 16

Between 25.4 mm (1 in.) and 31.75 mm (1.25 in.)

The conductor is placed through the center hole of the demagnetized Ketos ring.

Question 17

What type of steel is used in the Ketos ring test?

Answer 17

Ketos tool steel

It is heat treated to a Rockwell B-90 to B-95 hardness as specified in AS 5282.

Question 18

What should be done with accumulations of particles on the machine?

Answer 18

They should be cleaned off

Other components should also be checked for proper operation.

Question 19

What type of oils should be used as the carrier vehicle for magnetic particles?

Answer 19

AMS 2641, Type I

Type II materials may be used but are not recommended.

Question 20

What is the difference between Type I and Type II oils?

Answer 20

Flashpoint

Type II has a lower flashpoint.

Question 21

What tests are required by ASTM E 1444 / E 1444 M when charging or replacing the suspension?

Answer 21

A sample of the new suspension must be saved

This is for later comparison during suspension tests.

Question 22

What are the advantages of using water as a carrier instead of oil?

Answer 22

• Cleaner to work with
• Readily available
• Less expensive

Water also requires a pH check and water break test.

Question 23

What is the required concentration range for fluorescent particles in the suspension?

Answer 23

Between 0.1 mL and 0.4 mL/100 mL

For nonfluorescent particles, the range is between 1.2 mL and 2.4 mL/100 mL.

Question 24

What is the first step in testing the concentration of particles in a suspension bath?

Answer 24

Agitate the solution for a minimum of 30 min

This is followed by taking a sample and demagnetizing the solution.

Question 25

What should be evaluated in the **Particle Condition Check** after settling?

Answer 25

* Agglomeration * Brightness ## Footnote Fluorescent solutions are evaluated under ultraviolet light.

Question 26

What should the particles in the suspension be like during the **Particle Condition Check**?

Answer 26

Loose and not lumpy ## Footnote The brightness of the two samples should be relatively the same.

Question 27

What is the maximum percentage of **foreign particles** allowed in the solids during a **Particle Contamination Check**?

Answer 27

30 percent ## Footnote If contamination exceeds this limit, the suspension should be changed.

Question 28

What should be examined in the **Vehicle (Carrier) Contamination Check for Fluorescent Baths**?

Answer 28

The liquid above the precipitate with ultraviolet light ## Footnote Significant fluorescence indicates that the suspension should be changed.

Question 29

How is the **Brightness of the particles** evaluated?

Answer 29

By comparing in-use particles settled in the centrifuge tube to those in the unused suspension ## Footnote This test should be performed weekly.

Question 30

What is used to determine the **magnetic properties** of the particles?

Answer 30

A test part or the Ketos ring (AS 5282) ## Footnote The test part must be periodically cleaned to remove surface contamination.

Question 31

What does the **Water Break Check** determine?

Answer 31

If the water suspension will wet parts properly ## Footnote The test should be performed daily and results recorded.

Question 32

What is the maximum viscosity allowed at room temperature according to the **Viscosity Check**?

Answer 32

5 mm/s2 (5 centistokes) ## Footnote This test should be performed monthly.

Question 33

What is the normally accepted intensity of **ultraviolet light** at the test surface?

Answer 33

1000 μW/cm2 ## Footnote This measurement is made daily.

Question 34

What should be checked visually on **lenses or filters** used in magnetic particle testing?

Answer 34

Free from dirt, oils, cracks, or chips ## Footnote These factors may inhibit light transmission.

Question 35

What is the required light intensity when inspecting with **visible magnetic particles**?

Answer 35

1076 lx (100 ftc) ## Footnote This intensity should be checked weekly.

Question 36

What is the maximum permitted **ambient light** during evaluations?

Answer 36

22 lx (2 ftc) ## Footnote Measurements should be performed weekly or when lighting conditions change.

Question 37

What should not be used when **flammable vapors** may be present?

Answer 37

High-pressure ultraviolet lamps ## Footnote These lamps have high operating temperatures that can ignite flammable vapors.

Question 38

Who should perform a **safety review** before the first object is inspected?

Answer 38

A qualified technician ## Footnote Regular safety reviews are necessary to ensure ongoing safety.

Question 39

What can severe burns result from when using ultraviolet lamps?

Answer 39

Touching or contacting the surfaces ## Footnote Ultraviolet lamp housings and filters are extremely hot during operation.

Question 40

The temperature of an operating ultraviolet lamp can reach as high as _______.

Answer 40

121 °C (250 °F) ## Footnote This temperature is above the ignition or flashpoint of fuel vapors.

Question 41

What happens if fuel vapors contact the bulb of an ultraviolet lamp at high temperatures?

Answer 41

They burst into flame ## Footnote The ignition risk is significant due to the high temperatures of the bulb.

Question 42

True or false: The external surfaces of an ultraviolet lamp are not hot enough to cause burns.

Answer 42

FALSE ## Footnote The temperature may not be visually apparent but can still cause severe burns.

Question 43

What type of radiation may be extremely dangerous to unprotected skin and eyes?

Answer 43

Ultraviolet radiation ## Footnote Certain wavelengths of ultraviolet radiation pose significant health risks.

Question 44

Who should evaluate the **safety** of the ultraviolet radiation testing environment?

Answer 44

A qualified technician ## Footnote Safety evaluations are crucial for protecting users from hazards.

Question 45

High-pressure ultraviolet radiation sources are typically rated as having **high** in what potential?

Answer 45

Health hazard potential ## Footnote This rating indicates the risks associated with exposure.

Question 46

What should be monitored regarding ultraviolet radiation exposure?

Answer 46

Levels of time and intensity ## Footnote Monitoring is essential to ensure safety during use.