3.2u Mixed papers 1 (old) Flashcards
An MPI inspection on the brace of a K-node using closed wrap coils is to be conducted. Where would you place the Gauss Meter probe to verify the required
strength of 1T?
On the HAZ on the Chord side
What Material would repel external magnetic forces?
Bismuth
In simpler terms, the magnetic field generated by bismuth when it’s placed near a magnet opposes the magnet’s field, causing them to repel each other. This property of bismuth is due to the way its electrons behave in the presence of a magnetic field, resulting in the material exhibiting diamagnetic behavior.
To introduce a skin effect in a nodal weld, which terminals of a subsea MPI transformer would you connect the coils to:
AC and common
Which of the following NDT methods would be most suitable for sizing sub-surface defects in a welded joint?
Ultrasonics A-scan
Consequential poles are created due to:
Flux leakage
True or False: An AC current cannot produce a magnetic field
False
When an AC current passes through a coiled conductor, it produces what type of magnetic field?
Longitudinal magnetic field
In the formula Ipeak (ac) = 16xr÷N what does ‘N’ represent?
Number of coils
Which NDT method would not be used underwater, to detect an internal inclusion in a steel structure?
ACFM
Flux density is defined by?
The number of lines of magnetic force per unit area
The Right Hand Rule states?
The electric current is perpendicular to the magnetic field
The Hysteresis Loop is?
Flux density plotted aqainst external magnetising force
What is the result of two or more magnetic forces acting together called?
A vector field
Which of the following terms is sometimes used as the opposite of permeability?
Reluctance
A horseshoe magnet produces what type of magnetic field?
Longitudinal
True or False: Platinum is a paramagnetic material
False
Platinum is actually a diamagnetic material, not a paramagnetic one. Diamagnetic materials, like platinum, have a weak and opposite magnetic response to an applied magnetic field. This means they are slightly repelled by magnets. On the other hand, paramagnetic materials are weakly attracted to magnets, which is the opposite behavior.
ICCP systems use voltage/amperage values in which range?
30-80 volts DC/ 300-1000 amps
If a keeper plate was attached to a permanent magnet, which way would the fluxlines run through the keeper plate?
North to South
When lines of magnetic force jump the gap formed by a surface-breaking defect, it is called?
Flux leakage
The symbol used for magentising force is?
H
At the coercive point on a B/H curve, the material would:
Have zero flux density
The standard for the contents of fluorescent MPI ink states there should be?
0.1 to 0.3% by volume of ferrous particles
True or false:
Tungsten inclusions can be introduced if arcing occurs when using current flow prods
True
The typical range of settings for an MPI test using coils would be:
5 volts. 300 amps. 3 turns
An AC yoke will produce what type of magnetic affect?
Produce the skin affect
Why is it important that the test piece is not over-magnetised?
Over-magnetisation may produce non-relevant indications
An MPI inspection on the brace of a K-node using closed wrap coils is to be conducted. Where would you place the Gauss Meter probe to verify the required strength of 1T?
On the HAZ on the Chord side
To introduce a skin effect in a nodal weld, which terminals of a subsea MPI transformer would you connect the coils to:
AC and common
What NDT methods would be most suitable for sizing sub-surface defects in a welded joint?
Ultrasonics A-scan
List 8 reasons that can cause inaccurate UT readings
- Beam may reflect off an inclusion
- Backwall corrrosion
- Only Backwall echo will show, not the isolated pit
- Front wall corrosion
- Poor probe Contact
- If tha backwall is angled, the probe will not reflect back
- Beam reflects from the side walls of a long narrow plate
- If the material is verh hot a false reading will be given
MPI reuires what cleaning standards?
2.5
To measure the wall thickness of a steel plate, which probe would be used?
5MHz O° probe
What surface instrument would be used to verify the ferrous oxide particle content of MPI ink?
Sutherland flask
MPI reveals imperfections by indicating:
Flux leakage fields
The magnetising force for an MPI test is measured in:
Amps per metre
An HP water jet will achieve what standard of surface finish, when used on a painted steel structure?
SA3
SA3: Thorough blast cleaning to bright shiny metal. This is good for most inspection but will reflect light and is therefore not such a good surface if Video and Photography are employed.
WATER JET: Hazardous, leaves reflective surface
Before conducting a CP survey, a Bathycorrometer must be?
Immersed in fresh seawater for 30 minutes
Tested on the surface against a zinc block and unprotected steel
Tested on a zinc block at depth of operation and results noted
Note: All of these options
Prior to an MP inspection, checking a permanent magnet will lift 18kg serves, what purpose?
Checking that it has sufficient power to induce the field strength and meets he required standard
BS EN ISO 9934-1
Permanent 18kg - 75 to 100mm
Electro 4.5kg up to 300mm
The efficiency of a cathodic protection system can be assessed by?
Taking readings of electric potential
If aluminium is connected to mild steel and immersed in seawater, the aluminum will be?
The anode
Galvanic Series:
Graphite
Gold
Platinum
Silver
Stainless steel
Monel
Copper
Niobium
Tungsten
Lead
Cast iron
Mild steel
Aluminium
Zinc
Magnesium
On the pH scale which of the following values would be described as acidic?
pH 2.5
An ion is an atom that has which of the following characteristics?
Has a positive or negative charge
https://youtu.be/EIAaGHK5pjA?si=i_ZVLujDYE8jYqAS
The Pourbaix diagram displays which two sets of data from the following?
Electrode potential and pH value
On a structure protected by an ICCP system, a shadow area is identified, what could be done to improve the protection for that area?
Install a sacrificial anode in the area
Offshore structures use impressed current systems in preference to sacrificial systems because they?
Reduce the overall weight loading
A calomel cell selected from a pair to be used for calibrating a CP meter, should give which reading on a voltmeter?
+/- 2mV
ICCP systems use voltage/amperage values in which range?
30-80 volts DC/ 300-1000 amps
If a keeper plate was attached to a permanent magnet, which way would the flux lines run through the keeper plate?
North to South
When lines of magnetic force jump the gap formed by a surface-breaking defect, it is called?
Flux leakage
The symbol used for magnetising force is?
H
A small defect situated 10mm below the surface of a steel plate, can be found by
MPI, if?
AC is used
The material is stainless steel
Parallel conductors are used with AC
Answer: None of these options
MPI is used to:
Find surface defects
Slightly sub-surface
At the coercive point on a B/H curve, the material would:
Have zero flux density
Flux density is defined by?
The number of lines of magnetic force per unit area
The Right Hand Rule states?
The electric current is perpendicular to the magnetic field
The Hysteresis Loop is?
Flux density plotted against external magnetising force
What is the result of two or more magnetic forces acting together called?
A vector field
Which of the following terms is sometimes used as the opposite of permeability?
Reluctance
A horseshoe magnet produces what type of magnetic field?
Longitudinal
True or false: Platinum is a paramagnetic material
False
Platinum is diamagnetic, not paramagnetic. Diamagnetic materials are those that have a weak repulsion to magnetic fields, meaning they are slightly repelled by both north and south magnetic poles. In contrast, paramagnetic materials are weakly attracted to magnetic fields.
Which of the following methods could be used to locate an inclusion 2mm below the surface of a steel pipe?
Ultrasonic A-scan flaw detector
Weld profiling is?
A carefully controlled grinding process to relieve possible stress raisers
True of false: MPI can The method can accurately measure the depth of a crack
False
A method for the accurate determination of the extent of internal corrosion on a steel tubular is?
Ultrasonics using A-Scan
When using MPI to inspect welds, AC techniques are employed to?
Locate surface-breaking defects in ferritic steel
Which of the following techniques can be used to detect surface-breaking defects in welded structures?
a. Eddy current
b. ACFM
c. MPI
d. Correct: All of these options
If the direction of flow of magnetic lines of flux was due north, which of these defects would not show?
A defect running due south
If the direction of flow of magnetic lines of flux was due north, a defect running due south would not show up. This is because defects aligned perpendicular to the direction of the magnetic field will not disrupt the flow of magnetic lines and therefore will not produce a detectable indication.
Before commencing an MP inspection, a test on a mercury vapour UV lamp shows it producing 900uW/cm, would you?
Have the bulb in the lamp changed
Light BS EN ISO 3059
😎Day / Black Ink / 500 lux
🌚Night / fluorescent /20 Lux
🔦UV 1000 μW / cm2 @ 365-400nm wavelength
During an MP of a nodal weld using coils, which of the following would not be detected?
A lamination running parallel with the coil
The principal method of inspecting concrete structures is?
Visual inspection
When the ACFM technique is used for underwater inspection, it will?
a. Detect surface-breaking defects
b. Not require removal of paint coat
c.Give the depth of the defect
d. Correct: All of these options
Which method of magnetisation may be used to inspect a longitudinal seam
weld?
Encircling coil
Calomel reference cells are filled with which of the following solutions?
Potassium chloride
The calibration block used to calibrate UT flaw detectors is known as?
IIW V1 Block
When cleaning an area of steel with encrusted marine growth before MPI inspection, what is the preferred method?
Low pressure air/grit system
True or flase: Concerning MP ink
The grains should have high permeability
True
Which of the following is the current standard, for testing MPI inks?
BS EN ISO 9934-2:2002
When magnetic lines of force travel from an area of high permeability to an area of lower permeability they will?
Density decreases when moving from an area of higher permeability to an area of lower permeability
Which of the following statements best describes the term flux density?
The amount of flux lines per unit area
Which of the following is the correct procedure for the residual magnetism technique of MPI?
Switch on the power, apply the ink, inspect, switch off the power slowly
ACFM stands for?
Alternating current field measurement
For flooded member detection using ultrasonics, what frequency of probe would usually be selected?
0.5 MHZ
For flooded member detection, where higher penetration may be required to detect water ingress within structural members, the frequency might be lower to allow for deeper penetration. It’s common for FMD systems to use frequencies in the lower end of the ultrasonic range, sometimes around 200 kHz to 500 kHz.
So, for your specific frequencies:
200 kHz is equivalent to 0.2 MHz
500 kHz is equivalent to 0.5 MHz
Ultrasonic digital thickness measurements will not be reliable when?
Answer: All of these options
a. Front surface is corroded
b. Back wall is corroded
C. The back wall is not parallel
d. All of these options
Prior to doing an MPI, a CVI will be completed?
To identify areas that may cause spurious indication during MPI
As magnetic lines of force travel further from the magnetic poles, they will?
Decrease in density
CVI requires what cleaning standard?
SA 2.5
If exactly the same amount of magnetising force was applied to the following materials, which one would acquire the most flux density?
Nickel
Nickel acquires the most flux density when the same amount of magnetizing force is applied because it is a ferromagnetic material. Ferromagnetic materials, like nickel, iron, and cobalt, have a high magnetic permeability and a large positive magnetic susceptibility, which means they can become strongly magnetized when exposed to a magnetic field.
According to the manufacturer how long, does it take to fully charge, a new Buckley BathyCorrometer?
15 hours
When using a MPI coiled closed system with AC current on a nodal weld, this will produce:
An alternating maqnetic field
When using a permanent magnet, with a pole spacing of 150mm, what is the distance either side of the centre line of the magnet can be inspected:
75mm either side of the centre line
What is a field strength indicator, used for:
To check the strength of residual magnetism
Which of the following NDT methods requires the test piece to be cleaned, in accordance with SA2.5?
MPI
To measure the wall thickness of a steel plate, which probe would be used?
2.25MHz O° probe
Remember: Ultrasonic frequency used for testing is between 0.5Mhz and 6Mhz
Low: 0.5Mhz to 1.5Mhz - large grain - concrete
Higher: 2Mhz -6Mhz - fine grain - Steel
What surface instrument would be used to verify the ferrous oxide particle content of MPI ink?
A Sutherland Flask
MPI reveals imperfections by indicating:
Leakage fields
The magnetising force for an MPI test is measured in:
Amps per metre
The standard for the contents of fluorescent MP ink states there should be?
0.1 to 0.3% by volume of ferrous particles
True or false: Tungsten inclusions can be introduced if arcing occurs when using current flow prods
True
The typical range of settings for an MPI test using coils would be:
5 Volts, 300amps, 3 turns
An AC yoke will:
Produce the skin effect
Why is it important that the test piece is not over-magnetised?
Over-magnetisation may produce non-relevant indications
Consequential poles are created due to:
Flux leakage
True or false: An Ac current cannot produce a magnetic field
False
When an AC current passes through a coiled conductor, it produces what type of magnetic field?
Longitudinal magnetic field
In the formula Ipeak (ac) = 16xr÷N what does ‘N’ represent?
Number of coils
Which of the following would not be used underwater, to detect internal inclusion in a steel structure?
ACFM
