Flaw Probe Training

Standard Flaw Probes - OverviewGE Inspection Technologies

September 2004Bill Dunlap, Global Product Manager - Probes

© 2004 GE Inspection TechnologiesAll Rights Reserved

2© 2004 GE Inspection TechnologiesAll Rights Reserved

Typical Probe Construction

Monolithic Probe Piezocomposite Probe


Properties of Probes• The thickness and acoustic velocity of the piezoelectric

element determine the frequency of the probe.• A better acoustic match to test material or coupling medium

allows energy to couple into the load more efficiently. Echo signals will be correspondingly larger in amplitude and shorter in duration.

• Common ceramic (element) types include Lead Zirconate Titanate (PZT), Lead Metaniobate (LM), and Piezocomposite.

• ¼λ FACE LAYER is selected to maximize energy transfer out of the transducer into the coupling medium.

• BACKING (damping) shortens pulse length by absorbing energy from the ceramic; therefore it must match the acoustic impedance of the ceramic.


Three Series – Different PerformanceGamma Series

> Best combination of sensitivity and resolution

> Medium Bandwidth, 30% to 50%> Waveform 3 to 4 cycles typical

Applications> General purpose, most commonly

used probes> Suitable for most applications

requiring both sensitivity and resolution


Three Series – Different PerformanceAlpha Series

> Very highly damped> Lower sensitivity> Broadband, 50% to 100%> Short pulse – 1 to 2 cycles

Applications> Applications where resolution is

primary concern> Thickness measurement> Near-surface flaw detection> Delamination in layered materials,

e.g. composites> Flaws in thin materials


Three Series – Different PerformanceBenchmark Series

> Piezocomposite - newer technology> Best penetration (depth range)> High signal to noise ratio> Very high sensitivity> Usually better resolution than

Gamma> Best match to plastics and liquids

Applications> Angle beam inspection of welds> Inspection of plastics> Inspection of composites> General immersion applications


Contact Probes, Hard Face – RHP, XLCFeatures and Benefits

> RHP: hard ceramic face> XLC: super hard carbide face> Best match to metals> Element sizes (mm): 13, 19, 25> Comfortable grip> Gamma or Alpha Series> BNC connector, CR and CS

Applications> General purpose for larger parts

with simple geometry> Manual inspection of plate, large

forgings, billets, castings, etc.> Delaminations

RHP: Rugged High Performance

XLC: Extended Life Contact


Contact Probes, Hard Face – FFeatures and Benefits

> Hard ceramic face> Best match to metals> Element sizes (mm): 6, 10, 13> Gamma, Alpha, or Benchmark> Knurled housing – Gamma, Alpha> Plastic grip – Benchmark> Microdot connector

Applications> General purpose for manual flaw

detection and thickness gauging> Curved parts – pipe and tube,

tanks, bars, small forgings, etc.> Delaminations

F: Fingertip


Contact Probes, Delay Line – DFRFeatures and Benefits

> Alpha series, highly damped> Improves near surface resolution

for manual contact inspection> Long life – replaceable delay line> May be contoured for curved parts> Element sizes (mm): 3, 6, 13> Microdot connector

Applications> Thickness measurement> Detection of near surface flaws> Composite materials> Bond line inspection> Tubing and other curved parts

DFR: Delay Fingertip Removable


Contact Probes, Delay Line – K-PenFeatures and Benefits

> High resolution “pencil” probe> 7.5 MHz and 20 MHz> Very small contact area> Interchangeable delay lines> 1.7mm and 2.3mm tip diameters> Straight, 90°, and 45° models> Straight has removable handle> Microdot connector

Applications> Measure thickness on tightly

curved surfaces> Turbine blades> Wall thickness inside pit or small

indentation


Contact Probes, Delay Line – ZIP ProbesFeatures and Benefits

> Highly damped, low frequency> Delay line matched to composites

and plastics> Very high near surface resolution> High penetration (low frequency)> Three models:

– 450 KHz, 25mm element– 1.5 MHz, 13mm element– 2.25 MHz, 10mm element

> Microdot and BNC connectorsApplications

> Composite testing> Flaw detection and thickness of

plastic materials

ZIP: Zero Interface Probe


ZIP = “Zero Interface Probe

With uncoupled probe, delay tip echo is displayed.

Composite

Composite

When coupled, delay tip echo amplitude drops significantly. Displayed echo is backwall from 0.76 inch composite sample.


Thin Section Measurement

Acoustic matching allows thin sections to be measured at low frequency.


ZIP Probe Benefits

Low frequency (0.45 to 2.25 MHz) for maximum penetration

Highly damped for high resolution and sharp A-scan image

Acoustically matched to minimize or eliminate dead zone from delay tip


Contact Probes, Protective Face – PFCFeatures and Benefits

> Gamma series, general purpose> Use 1 probe with 3 different

protective faces:– Membrane– Nylon wear cap– High temperature delay line

> BNC connector, CR and CSApplications

> General purpose for larger parts with simple geometry

> Plates, billets, bars, forgings> Inspection at high temperature

PFC: Protective Face Combination


Contact Probes, Protective Face – PMFeatures and Benefits

> Gamma series, general purpose> Soft membrane improves coupling

to rough, uneven or curved surfaces> BNC connector, CR and CS

Applications> General purpose for larger parts

uneven surfaces> Plates, billets, bars, forgings

Recommendation> B..S and MB..S from Köln are

superior for most applications requiring membrane probes

PM: Protective Membrane


Angle Beam Probes – SWSFeatures and Benefits

>Refracted shear (transverse) wave>Gamma or Benchmark series>Sizes (mm): 13Ø, 13x25, 19x25, 25Ø>Interchangeable wedges for steel, 45°,

60°, 70° and 90° shear wave>Custom wedges available:

– Contoured, longitudinal wave, high temperature to 200°C, other metals

>BNC connectorApplications

>General weld inspection, larger objects>Pipes, tanks, axles, forgings, castings,

bridges, structures, etc.

SWS: Shear Wave Standard


Angle Beam Probes – MSW-QCFeatures and Benefits

>Refracted shear (transverse) wave>Gamma, Benchmark, or Alpha series>Element diameters (mm): 6, 10, 13>Interchangeable wedges for steel, 45°, 60°, 70°

and 90° shear wave>Custom wedges available:

– Contoured, longitudinal wave, other metals>Quick change wedge design>Microdot connector

Applications>General weld inspection, smaller or thinner

objects>Tubes, pipes, tanks, pumps, valve housings,

turbine blades, etc.

MSW-QC: Miniature Shear Wave –Quick Change


Angle Beam Probes – ABFPFeatures and Benefits

>Refracted shear wave, integral wedge>Gamma series>Element sizes (mm): 5x5, 6x6>Microdot connector

Applications>Tubes, pipes, tanks, pumps, valve

housings, turbine blades, etc.>Pipe seam welds>Aluminum airframe

Recommendation>Use MWB or MWK from Köln where

possible

ABFP: Angle BeamFingertip Potted


Angle Beam Probes – SMSWSFeatures and Benefits

>Refracted shear (transverse) wave>Gamma series>Very small, 3mm element diameter>Interchangeable wedges for steel, 45°,

60°, 70° and 90° shear wave>Custom wedges available:

– Contoured, longitudinal wave, other metals>Miniature microdot connector

Applications>Angle beam testing of very small or

very thin parts>Tubes, thin wall containers, turbine

blades, etc.

SMSWS: Sub-MiniatureShear WaveStraight


Dual Element Probes – ADP, RCFeatures and Benefits

>Separate transmit and receive elements improves near surface resolution

>Small, fingertip size; element diameters 6mm, 10mm and 13mm

>Couples well on rough or curved surface>Reduces noise due to scattering>Can be contoured for curved parts>ADP has potted cable>RC has 4-pin LEMO connector

Applications>Wall thickness, corrosion, erosion>Small, near surface flaw detection>Small parts, e.g., screws, bolts, pins, etc.

ADP: Advanced Dual PottedRC: Replaceable Cable


Dual Element Probes – High TemperatureFeatures and Benefits

>HT400A can be used with flaw detectors for inspection of hot materials up to 500°C, intermittent contact

>KBA560V can be used with flaw detectors for inspection of hot materials up to 400°C, intermittent contact

Applications>General thickness, corrosion and erosion

on hot parts>Near surface flaw detection on hot parts

HT400AKBA560V


Dual Element Probes – DU, DU-FFeatures and Benefits

>Separate transmit and receive elements improves near surface resolution

>Reduces noise due to scattering>Can be contoured for curved parts>DU replaceable delays - long service life>DU-F fixed delays and piezocomposite

elements - maximum sensitivity>Microdot connectors

Applications>Railroad wheels>Core flaws in shafts, bars, billets, etc.>Corrosion, erosion>Coarse grain materials

DU

DU-F


Immersion Probes – ISS, ISFeatures and Benefits

>Acoustically matched for best efficiency in water

>Gamma, Alpha, or Benchmark Series>Element sizes (mm): 6, 10, 13, 19, 25>Can be focused to a point (spherical) or

to a line (cylindrical)>Waterproof UHF connector

Applications>Parts with irregular geometry>Automated scanning>On-line thickness measurement>High speed flaw detection in pipe, tube,

plate, bar, etc.

ISS: Immersion Straight SlimIS: Immersion Straight


Immersion Probes – IPS, IRFeatures and Benefits

>Gamma or Alpha Series>Element sizes (mm): 6 (IPS, IR); 10, 13

(IR only)>Can be focused to a point (spherical) or

to a line (cylindrical)>IR has Waterproof UHF connector>IPS has non-waterproof microdot

Applications>Parts with irregular geometry>Automated scanning>On-line thickness measurement>High speed flaw detection in pipe, tube,

plate, bar, etc.

IPS: Immersion Pencil StraightIR: Immersion Right Angle


Two Types of Focused Probes


Advantages of Focusing


Focal length in steel is ¼ that in water due to higher velocity.


Focusing• Single-element transducers are often focused to narrow the

beamwidth for better lateral resolution in the focal zone (poorer resolution beyond).

• This is accomplished using a lens which curves the wavefront.

ConvergingRegion

DivergingRegion


Nearfield Farfield

λ4

2DN =

Nearfield / Farfield• The sound field cannot be focused beyond the Nearfield

distance.

• Longer focus requires higher frequency or larger element to extend the nearfield.


Practical Limits on Focal Length

1. You cannot focus longer than the near field point of the probe.

2. You cannot focus shorter than the mechanical limit for lens curvature.


Probes For Every (?) Application

Contact

Angle Beam

ImmersionDual - thin sections...

Flaw Probe Training

Documents

Transcript of Flaw Probe Training