In Depth Look at UltrasonicTransducers
In Depth Look at UltrasonicTransducers
In Depth Look at UltrasonicTransducers
El. Venizelou 7 & Delfon, Metamorfosi 14452 Athens, Greece tel: +30 210 2846 801-4, fax: +30 210 2846 805 sales@envirocoustics.gr, www.envirocoustics.gr
Table of Contents
Transducer Selection .................................2-3 Part Number Configurations......................... 4 Test and Documentation............................... 5 Contact Transducers..................................6-7
Fingertip .............................................................................. 6 Standard ............................................................................. 7 Magnetic Hold Down .......................................................... 7
Gage Dual Transducers .........................30-3 Special Transducers ..............................32-33 Test Blocks.............................................34-35 Cables ....................................................36-37 Couplants and Adaptors ............................. 38 Technical Notes .....................................39-48
Normal Incidence Shear Wave Transducers ................................................ 5 Delay Line Transducers .........................6-7
Replaceable Delay Line and Options ............................... 6 Sonopen Replaceable Delay Line ................................... 7
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Transducer Selection
The transducer is one of the most critical components of any ultrasonic system. A great deal of attention should be paid to selecting the proper transducer for the application. The performance of the system as a whole is of great importance. Variations in instrument characteristics and settings as well as material properties and coupling conditions play a major role in system performance. We have developed three different series of transducers to respond to the need for variety. Each series has its own unique characteristics.
Transducer configuration also has an impact on system performance. Consideration should be given to the use of focused transducers, transducers with wear surfaces that are appropriate for the test material, and the choice of the appropriate frequency and element diameter. The summaries below provide a general description of the performance characteristics of each transducer series. While these guidelines are quite useful, each application is unique and performance will be dependent on electronics, cabling, and transducer configuration, frequency, and element diameter.
SIGNAL WAVEFORM
0.8
ACCUSCAN S
The Accuscan S series is intended to provide excellent sensitivity in those situations where axial resolution is not of primary importance. Typically this series will have a longer wave form duration and a relatively narrow frequency bandwidth.
1.0 0.8 0.6
FREQUENCY SPECTRUM
0.4 (VOLT)
3.85 -6 dB
6.2
0.0
0.4
-0.4
0.2
0.0
5 (MHz)
10
SIGNAL WAVEFORM
0.8
CENTRASCAN
The piezocomposite element Centrascan Series transducers provide excellent sensitivity with a high signal-to-noise ratio in difficult-to-penetrate materials. They have exceptional acoustic matching to plastics and other low impedance materials.
0 -10 -20 dB
FREQUENCY SPECTRUM
2.67 7.0
0.4 mV / Division
0.0
-30
-0.4
-40
-50 0
5 (MHz)
10
SIGNAL WAVEFORM
0.8
VIDEOSCAN
Videoscan transducers are untuned transducers that provide heavily damped broadband performance. They are the best choice in applications where good axial or distance resolution is necessary or in tests that require improved signal-to-noise in attenuating or scattering materials.
1.0 0.8 0.6
FREQUENCY SPECTRUM
0.4 (VOLT)
0.0
2.25 -6 dB
7.8
0.4
-0.4
0.2
0.0
5 (MHz)
10
Note: For more information on bandwidth and sensitivity versus resolution, please refer to the Technical Notes located on pages 39-48. Note: For sample test forms of transducers that you are interested in purchasing or if you have questions, please contact us via phone, fax, or e-mail.
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Transducer Selection
Contact Transducers: A contact transducer is a single element transducer, usually generating a longitudinal wave, that is intended for direct contact with a test piece. All contact transducers are equipped with a WC5 wear face that offers superior wear resistance and probe life as well as providing an excellent acoustic impedance match to most metals. Please see page 6 for more details on longitudinal contact probes or page 15 for info on normal incidence shear wave transducers.
Dual Element Transducers: A dual element transducer consists of two longitudinal wave crystal elements (one transmitter and one receiver) housed in the same case and isolated from one another by an acoustic barrier. The elements are angled slightly towards each other to bounce a signal off the backwall of a part in a V-shaped pattern. Dual element transducers typically offer more consistent readings on heavily corroded parts, and can also be used in high temperature environments. See page 8 for more information on dual element transducers for flaw detection or page 30 for dual element probes for use with PanametricsNDT corrosion gages.
Angle Beam Transducers: Angle beam transducers are single element transducers used with a wedge to introduce longitudinal or shear wave sound into a part at a selected angle. Angle beam transducers allow inspections in areas of a part that cannot be accessed by the ultrasonic path of a normal incidence contact transducer. A common use for angle beam transducers is in weld inspection, where a weld crown blocks access to the weld zone of interest for a standard contact transducer and where typical flaw alignment produces stronger reflections from an angled beam. Please see page 10 for additional information on angle beam transducers and wedges. For a detailed explanation of how wedges are designed using Snells Law please see page 44 of the Technical Notes.
Delay Line Transducers: Delay line transducers are single element broadband contact transducers designed specifically to incorporate a short piece of plastic or epoxy material in front of the transducer element. Delay lines offer improved resolution of flaws very near to the surface of a part and allow thinner range and more accurate thickness measurements of materials. Delay lines can be contoured to match the surface geometry of a part and can also be used in high temperature applications. For more information on delay line transducers and delay line options, please see page 16.
Protected Face Transducers: Protected face transducers are single element longitudinal wave transducers with threaded case sleeves, which allow for a delay line, wear cap or membrane. This makes them extremely versatile and able to cover a very wide range of applications. Protected face transducers can also be used as a direct contact transducer on lower impedance materials such as rubber or plastic for an improved acoustic impedance match. Please see page 18 for more information on protected face transducers and the options available for use with them.
Immersion Transducers: Immersion transducers are single element longitudinal wave transducers, whose wear face is impedance matched to water. Immersion transducers have sealed cases allowing them to be completely submerged under water when used with a waterproof cable. By using water as both a couplant and delay line, immersion transducers are ideal for use in scanning applications where consistent coupling to the part is essential. As an additional option, immersion transducers can also be focused to increase the sound intensity in a specific area and decrease the spot size of the sound beam. For additional information on immersion transducers, please see page 20. For an in depth explanation of focusing, please see page 44 of the Technical Notes.
High Frequency Transducers: High frequency transducers are either delay line or focused immersion transducers and are available in frequencies from 20 MHz to 225 MHz. High frequency delay line transducers are capable of making thickness measurements on materials as thin as 0.0004 (0.010 mm) (dependent on material, transducer, surface condition, temperature and setup), while high frequency focused immersion transducers are ideal for high resolution imaging and flaw detection applications on thin, low attenuation materials such as silicon microchips. For more information on all high frequency transducers, please see page 26.
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RM
SM
SU
RP
Right Angle Microdot Straight Microdot Right Angle Potted Cable Terminating in BNC Connectors
Straight UHF
Contoured Delays
CC-R
Contoured Wedges
AID AOD
Focal Types
F
(Immersion Transducers)
Spherical Focus Cylindrical Focus
CF
Concave Radius
CX-R
CID
Convex Radius
COD
Focal Designations FPF Circumferential Inside Diameter Circumferential Outside Diameter OLF PTF Flat Plate Focus Optical Limit Focus Point Target Focus
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Contact Transducers
Advantages:
Proprietary WC-5 wear plate increases durability, fracture resistance, and wear resistance All styles are designed for use in rugged industrial environments Close acoustic impedance matching to most metals Can be used to test a wide variety of materials
A contact transducer is a single element longitudinal wave transducer intended for use in direct contact with a test piece.
Nominal Element Size inches 1.00 1.00 0.75 0.50 1.00 0.75 mm 25 25 19 13 25 19 13 10 6 25 19 13 10 6 25 19 13 10 6 3 13 10 6 13 10 6 3 6 3 A1O1S-RM A102S-RM A114S-RM A103S-RM A104S-RM A105S-RM A106S-RM A125S-RM A133S-RM A18OS-RM A181S-RM A182S-RM A183S-RM A184S-RM A107S-RM A108S-RM A109S-RM A126S-RM A11OS-RM A12OS-RM A122S-RM A121S-RM A111S-RM A127S-RM A112S-RM A113S-RM
Transducer Part Numbers ACCUSCAN-S CENTRASCAN C106-RM C125-RM C133-RM C109-RM C126-RM C110-RM VIDEOSCAN V1O1-RM V102-RM V114-RM V103-RM V104-RM V105-RM V106-RM V125-RM V133-RM V181-RM V182-RM V183-RM V107-RM V108-RM V109-RM V126-RM V11O-RM V1091 V122-RM V121-RM V111-RM V127-RM V112-RM V129-RM V113-RM V116-RM
Applications:
Straight beam flaw detection and thickness gaging Detection and sizing of delaminations Material characterization and sound velocity measurements Inspection of plates, billets, bars, forgings, castings, extrusions, and a wide variety of other metallic and non-metallic components For continuous use on materials up to 122F / 50C
2.25
Fingertip Contact
Units larger than 0.25 (6 mm) are knurled for easier grip 303 stainless steel case Low profile for difficult-to-access surfaces Removable plastic sleeve for better grip available upon request at no additional charge, part number CAP4 for 0.25 (6 mm) and CAP8 for 0.125 (3 mm) Standard configuration is Right Angle and fits Microdot connector
3.5
0.5 0.375 0.25 1.00 0.75 0.50 0.375 0.25 0.125 0.50
5.0
7.5
10
Transducer Dimensions (in inches) Nominal Element Size 1.00 0.75 0.50 0.375 0.25 0.125 (A) 1.25 1.00 0.70 0.53 0.35 0.25 (B) 0.63 0.63 0.63 0.50 0.42 0.38
15 20
A110S-SM
V113-SM
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Standard Contact
Comfort Fit Sleeves designed to be easily held and to provide a steady grip while wearing gloves 303 stainless steel case Large element diameters for increased sound energy and greater coverage Standard connector style is Right Angle BNC (RB), may be available in a Straight BNC (SB)
Frequency MHz 0.1 0.25 0.5 Nominal Element Size inches 1.50 1.50 1.5 1.125 1.00 1.50 1.125 1.0 1.00 0.75 0.50 1.5 1.125 2.25 1.00 0.75 0.50 0.25 x 1 1.00 3.5 0.75 0.50 1.00 5.0 7.5 10 0.75 0.50 0.50 0.50 mm 38 38 38 29 25 38 29 25 19 13 38 29 25 19 13 6 x 25 25 19 13 25 19 13 13 13 Transducer Part Numbers ACCUSCAN-S A189S-RB A191S-RB A1O1S-RB A192S-RB A194S-RB A102S-RB A114S-RB A103S-RB A195S-RB A197S-RB A104S-RB A105S-RB A106S-RB A188S-RB* A18OS-RB A181S-RB A182S-RB A107S-RB A108S-RB A109S-RB A12OS-RB A111S-RB VIDEOSCAN V1011 V1012 V189-RB V191-RB V1O1-RB V192-RB V194-RB V102-RB V114-RB V103-RB V195-RB V197-RB V104-RB V105-RB V106-RB V180-RB V181-RB V182-RB V107-RB V108-RB V109-RB V120-RB V111-RB
CENTRASCAN C103-SB
Transducer Dimensions (in inches) Nominal Element Size 1.50 1.50* 1.125 1.00 0.25 x 1.00 0.75 0.50 (A) 1.75 1.75 1.38 1.25 1.25 1.00 0.63 (B) 2.23 2.50 1.79 1.60 1.60 1.37 1.16 (C) 1.25 2.50 1.25 1.25 1.25 1.25 1.25
M1057
M1057
Part Number
Note: All above magnetic hold down transducers have straight Microdot connectors.
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A dual element transducer consists of two crystal elements housed in the same case, separated by an acoustic barrier. One element transmits longitudinal waves, and the other element acts as a receiver.
For information on transducers for all MG2 and 37 series thickness gages see pages 30-31.
Advantages:
Improves near surface resolution Eliminates delay line multiples for high temperature applications Couples well on rough or curved surfaces Reduces direct back-scattering noise in coarse grained or scattering materials Combines penetration capabilities of a lower frequency single element transducer with the near surface resolution capabilities of a higher frequency single element transducer Can be contoured to conform to curved parts
Two angled elements create a V-shaped sound path in the test material. This "Pseudo-Focus" enhances resolution in the focal zone.
Applications:
Remaining wall thickness measurement Corrosion/erosion monitoring Weld overlay and cladding bond/disbond inspection Detection of porosity, inclusions, cracks, and laminations in castings and forgings Crack detection in bolts or other cylindrical objects Maximum temperature capability is 800F (425C) for 5.0 MHz and below; 350F (175C) for 7.5 MHz and 10 MHz. Recommended duty cycle for surface temperatures from 200F (90C) to 800F (425C) is ten seconds maximum contact followed by a minimum of one minute air cooling (does not apply to Miniature Tip Dual)
DHC706-RM
BCMD-316-5F
DHC711-RM
Nominal Element Size inches 0.50 0.50 0.25 0.50 0.25 0.25 mm 13 13 6 13 6 6
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Fingertip Duals
Knurled case, except the 0.25 (6 mm) element size High-strength flexible 6 (1.8 m) potted cable (fits BNC or Large Lemo 1 connectors)
Frequency MHz 1.0 2.25 Nominal Element Size inches 0.75 0.50 0.75 0.50 0.375 0.25 3.5 0.75 0.50 0.375 0.25 5.0 0.75 0.50 0.375 0.25 7.5 10 0.50 0.25 0.50 0.25 mm 19 13 19 13 10 6 19 13 10 6 19 13 10 6 13 6 13 6 Transducer Part Numbers Fits BNC Connector D714-RP D703-RP D705-RP D706-RP D771-RP D785-RP D781-RP D782-RP D783-RP D784-RP D708-RP D709-RP D710-RP D711-RP D720-RP D721-RP D712-RP D713-RP Fits Large Lemo Connector D714-RPL1 D703-RPL1 D705-RPL1 D706-RPL1 D771-RPL1 D785-RPL1 D781-RPL1 D782-RPL1 D783-RPL1 D784-RPL1 D708-RPL1 D709-RPL1 D710-RPL1 D711-RPL1 D720-RPL1 D721-RPL1 D712-RPL1 D713-RPL1
D706-RP
Provides better coupling on curved surfaces Low profile allows for better access in areas of limited space Maximum temperature capability 122F (50C)
Frequency MHz 5.0 Tip Diameter inches 0.20 mm 5 Nominal Element Size inches 0.15 mm 3.8 MTD705 Transducer Part Number
D705-RP
D711-RP
Transducer Dimensions (in inches) Nominal Element Size 1.00* 0.75 0.50 0.50* 0.375 0.25 (A) 1.25 1.00 0.70 0.70 0.53 0.35 (B) 0.75 0.75 0.75 0.63 0.62 0.54 ((C) 1.00 0.75 0.50 0.61 0.375 0.25
BCLPD-78-5
Angle beam transducers are single element transducers used with a wedge to introduce a refracted shear wave or longitudinal wave into a test piece.
Three-material design of our Accupath wedges improves signal-tonoise characteristics while providing excellent wear resistance High temperature wedges available for in-service inspection of hot materials Wedges can be customized to create nonstandard refracted angles Available in interchangeable or integral designs Contouring available Wedges and integral designs are available with standard refracted angles in aluminum (see page 13)
Applications:
Flaw detection and sizing For time-of-flight diffraction transducers see page 25 Inspection of pipes, tubes, forgings, castings, as well as machined and structural components for weld defects or cracks
Miniature Angle Beam Transducers and Wedges are used primarily for testing of weld integrity. Their design allows them to be easily scanned back and forth and provides a short approach distance.
C543-SM ABWM-4T-X
Transducer Part Numbers ACCUSCAN-S A539S-SM A540S-SM A545S-SM A541S-SM A547S-SM A548S-SM A549S-SM A550S-SM A551S-SM A552S-SM A542S-SM A546S-SM A543S-SM A544S-SM CENTRASCAN C548-SM C540-SM C545-SM C541-SM C549-SM C550-SM C551-SM C542-SM C546-SM C543-SM C544-SM VIDEOSCAN V539-SM V540-SM V545-SM V541-SM V547-SM V549-SM V550-SM V551-SM V552-SM V542-SM V546-SM V543-SM V544-SM
Nominal Element Size 0.50 0.375 0.25 Trasnducer Dimensions (in inches) (A) 0.71 0.58 0.44 (B) 0.685 0.65 0.55 (C) 0.257 0.257 0.22 Thread Pitch 11/16 - 24 9/16 - 24 3/8 - 32
0.50
13
0.375
10
0.25
0
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Accupath Wedges
Small wedge footprint Pointed toe design allows transducer rotation even when the nose is touching a weld crown Special wedge design for use with 10 MHz transducer
ABSA-5T-X
ABSA-7T-X ABSA-4T-X
Wedge Part Numbers Short Approach ABSA-5T-X ABSA-7T-X ASSA-4T-X Accupath* ABWM-5T-X ABWM-7T-X ABWM-4T-X High Temp* 500F (260C) ABWHT-5T-X ABWHT-7T-X ABWHT-4T-X Very High Temp* 900F (480C) ABWVHT-5T-X ABWVHT-7T-X ABWVHT-4T-X Surface Wave 90 ABWML-5T-90 ABWML-7T-90 ABWML-4T-90
mm 13 10 6
Short Approach Wedges are available in standard refracted shear wave angles of 45, 60, and 70 in steel at 5.0 MHz. *Accupath Wedges are available in standard refracted shear wave angles of 30, 45, 60, and 70 in steel at 5.0 MHz.
Wedge Part Numbers Short Approach ABSA-5T-X ABSA-7T-X ASSA-4T-X Accupath* ABWM-5ST-X ABWM-7ST-X ABWM-4ST-X Surface Wave 90 ABWML-5ST-90 ABWML-7ST-90 ABWML-4ST-90
mm 13 10 6
Short Approach Wedges are available in standard refracted shear wave angles of 45, 60, and 70 in steel at 5.0 MHz. *Accupath Wedges are available in standard refracted shear wave angles of 30, 45, 60, and 70 in steel at 10 MHz.
Short Approach Wedge Dimensions (Miniature Screw-in) Fits Nominal Element Size (in inches) 0.5 (A) 45 60 70 0.70 0.74 0.79 (B) 1.03 1.19 1.34 (C) 0.73 0.73 0.73 (D) 0.38 0.45 0.50 (A) 0.60 0.67 0.69 (B) 0.85 1.00 1.12 0.375 (C) 0.61 0.61 0.61 (D) 0.32 0.367 0.406 (A) 0.43 0.48 0.50 (B) 0.61 0.71 0.81 0.25 (C) 0.43 0.43 0.43 (D) 0.235 0.268 0.305
Accupath and Surface Wave Wedge Dimensions* (Miniature Screw-in) Fits Nominal Element Size (in inches) 0.5 (A) 30 45 60 70 90 0.72 0.70 0.74 0.79 1.25 (B) 1.22 1.03 1.19 1.34 1.84 (C) 0.77 0.73 0.73 0.73 0.77 (D) 0.54 0.38 0.45 0.50 (A) 0.62 0.60 0.67 0.69 1.00 (B) 1.03 0.85 1.00 1.12 1.48 0.375 (C) 1.03 0.61 0.61 0.61 1.48 (D) 0.42 0.32 0.367 0.406 (A) 0.49 0.43 0.48 0.50 0.83 (B) 0.66 0.61 0.71 0.81 1.13 0.25 (C) 0.45 0.43 0.43 0.43 0.45 (D) 0.23 0.235 0.268 0.305
*Wedge dimensions for 10 MHz transducers are slightly different, please consult us for details.
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Standard Angle Beam Transducers and Wedges offer a large scanning index, which allows for a shorter scan time on larger test surfaces.
Transducer Part Numbers ACCUSCAN-S A414S-SB A407S-SB A408S-SB A411S-SB A409S-SB A413S-SB A401S-SB A403S-SB A412S-SB A405S-SB A402S-SB A404S-SB A415S-SB A406S-SB CENTRASCAN C407-SM C408-SB C411-SB C401-SB C403-SB C412-SB C405-SB C402-SB C404-SB C415-SB C406-SB VIDEOSCAN V414-SB V407-SB V408-SB V409-SB V413-SB V401-SB V403-SB V405-SB V402-SB V404-SB V406-SB ABWS-1-X ABWS-2-X ABWS-3-X Accupath*
Wedge Part Numbers High Temp* 500F (260C) Very High Temp* 900F (480C) Surface Wave 90
1.00
25
2.25 3.5 5.0 0.5 1.0 2.25 3.5 5.0 1.0 2.25 3.5 5.0
ABWHT-3-X
ABWVHT-3-X
ABWSL-3-90
0.50 x l.00
13 x 25
ABWHT-2-X
ABWVHT-2-X
ABWSL-2-90
0.50
13
ABWHT-1-X
ABWVHT-1-X
ABWSL-1-90
*Wedges are available in standard refracted shear wave angles of 30, 45, 60, and 70 in steel at 5.0 MHz.
Accupath and Surface Wave Wedge Dimensions (Standard) Nominal Element Size (in inches) 1.00 (A) 30 45 60 Dimension A = Wedge Height Dimension D = Approach Distance 70 90 1.69 1.47 1.50 1.50 1.50 (B) 2.15 1.96 2.18 2.47 2.50 (C) 1.62 1.63 1.63 1.63 1.65 (D) 1.15 0.97 1.00 1.13 0.44 (A) 1.30 1.30 1.30 1.35 1.20 0.50 x 1.00 (B) 1.30 1.41 1.50 1.77 1.34 (C) 1.60 1.60 1.60 1.60 1.60 (D) 0.76 0.78 0.67 0.85 (A) 1.20 1.20 1.20 1.20 1.20 (B) 1.42 1.31 1.48 1.58 1.34 0.50 (C) 1.10 1.08 1.08 1.09 1.00 (D) 0.83 0.70 0.68 0.68
ABWS-1-X ABWS-2-X
Nominal Element Size 1.00 0.50 x 1.00 0.50 Transducer Dimensions (in inches) (A) 1.25 0.73 0.72 (B) 0.63 0.63 0.63 (C) 1.38 1.31 0.81 (D) 1.65 1.53 1.02
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A592S-SM
A592S-RM
Transducer Case
Material
Transducer Part Numbers 60 A562S-RM A572S-RM A592S A5023 A5014 A5068 70 A563S-RM A573S-RM A593S A5021 A5013 A5054 A5069 90 A564S-RM* A574S-RM* see note* A5053* see note*
Miniature
0.25 x 0.25
Micro-Miniature
0.187 x 0.187
5 x 5
*A564S-RM, A574S-RM and A5053 create surface waves in steel and aluminum.
0.187", RM STYLE
A5023
0.187", SM STYLE
A5014
A564S-RM
Contoured Wedges
Improves coupling on curved surfaces When ordering, please specify wedge type, contour orientation, and contour diameter Example Part #: ABWM-4T-45-COD-1.25IN
* Wedges are available in standard refracted shear wave angles of 45, 60 and 70 in steel. Please specify upon ordering.
ABWS-8-X C430-SB
C432-SB ABWS-6-X
Snail Wedges
Snail Wedge Dimensions* (in inches) (A) 45 60 70 2.15 1.91 2.17 (B) 0.62 0.65 0.67 (C) 1.78 1.81 1.92 (D) 1.25 1.25 1.25
Accupath Wedges
Accupath Wedge Dimensions* (in inches) (A) 45 60 70 1.50 1.68 1.66 (B) 0.90 0.79 0.96 (C) 1.96 2.05 2.20 (D) 1.50 1.50 1.50
CDS Wedges
CDS Wedges are used in the 30-70-70 technique for crack detection and sizing. They are compatible with our replaceable miniature screw-in angle beam transducers, making them an economical alternative to other commercially available products. For transducers, see page 10.
Fits Nominal Element Size inches 0.25 0.375 mm 6 10 CDS-4T CDS-7T Wedge Part Number
CDS-7T
C551-SM CDS-4T
A543S-SM
Understanding CDS
The 30-70-70 crack detection technique uses a single element transducer with a CDS wedge for detection and sizing of ID connected cracks. This technique uses a combination of three waves for sizing flaws of different depths. An OD creeping wave creates a 31.5 degree indirect shear, (red in diagram to the left), wave which mode converts to an ID creeping wave; this will produce a reflected signal on all ID connected cracks. A 30 degree shear wave, (yellow in diagram to the left), will reflect off the material ID at the critical angle and mode convert to a 70 degree longitudinal wave; a signal will be received by the transducer on mid-wall deep cracks. A 70 degree longitudinal wave, (blue in diagram to the left), will reflect off the tip of a deep wall crack. Based on the presence or absence of these three waves, both detection and sizing of ID connected cracks is possible.
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Advantages:
Generate shear waves which propagate perpendicular to the test surface For ease of alignment, the direction of the polarization of shear wave is nominally in line with the right angle connector The ratio of the longitudinal to shear wave components is generally below -30 dB
We recommend the use of our SWC shear wave couplant for general purpose testing.
Applications:
Shear wave velocity measurements Calculation of Youngs Modulus of elasticity and shear modulus (see Technical Notes, page 46) Characterization of material grain structure
V157-RM
Transducer Part Numbers Standard Case V1548 V150-RB V151-RB V152-RB V153-RB V154-RB V155-RB Fingertip Case V150-RM V151-RM V152-RM V153-RM V154-RM V155-RM V156-RM V157-RM
Delay sec 7 7 7 7 4
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Advantages:
Heavily damped transducer combined with the use of a delay line provides excellent near surface resolution Higher transducer frequency improves resolution Improves the ability to measure thin materials or find small flaws while using the direct contact method Contouring available to fit curved parts
Applications:
Precision thickness gaging Straight beam flaw detection Inspection of parts with limited contact areas
V206-RM
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DLP-301 V260-SM
V260-45
V260-RM
Part Number
V2054
V2055
V2034
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Advantages:
Provides versatility by offering removable delay line, protective wear cap, and protective membrane When the transducer is used alone (without any of the options), the epoxy wear face provides good acoustic impedance matching into plastics, many composites, and other low impedance materials Cases are threaded for easy attachment to the delay line, protective membrane, and wear cap options
Applications:
Straight beam flaw detection Thickness gaging High temperature inspections Inspection of plates, billets, bars, and forgings
A606S-SB A604S-RB A609S-RB
Frequency MHz
Transducer Part Numbers ACCUSCAN-S CENTRASCAN C602-RB C603-RB C604-RB C606-RB C609-RB VIDEOSCAN V689-RB V691-RB V601-RB V692-RB V694-RB V602-RB V614-RB V603-RB V695-RB V697-RB V604-RB V605-RB V606-RB V680-RB V681-RB V682-RB V607-RB V608-RB V609-RB V611-RB
Nominal Element Size 1.50 1.125 1.00 0.75 0.50 Transducer Dimensions (in inches) (A) 1.53 1.53 1.53 1.53 1.53 (B) 1.75 1.38 1.25 0.99 0.63 (C) 2.25 1.81 1.63 1.41 1.19
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VHTD
HTD
WTD
*Recommended usage cycle is ten seconds maximum contact followed by one minute of air cooling. However, the transducer itself should not be heated above 122F (50C). X = standard delay line lengths, available in 1/2 (13 mm), 1 (25 mm), 1-1/2 (38 mm). Specify at time of ordering. Note: For the delay lines above, a room temperature material longitudinal wave velocity of 0.100 in/sec 0.005 in/sec may be used as an approximation for basic calculations. This value should not be used for engineering design calculations. Contact us for details.
NWC-5
MRN-5 MRN-1
NWC-3
PM
*Available in 36 x 36 x 1/32 sheets. Order part number NPD-665-3101. Kit includes 12 Membranes, 1 ring, C-2 couplant
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Immersion Transducers
Advantages:
The immersion technique provides a means of uniform coupling Quarter wavelength matching layer increases sound energy output Corrosion resistant 303 stainless steel case with chrome-plated brass connectors Proprietary RF shielding for improved signal-tonoise characteristics in critical applications All immersion transducers, except paintbrush, can be focused spherically (spot) or cylindrically (line) (see Technical Notes page 45) Customer specified focal length concentrates the sound beam to increase sensitivity to small reflectors
Unfocused
Focused
An immersion transducer is a single element longitudinal wave transducer with a 1/4 wavelength layer acoustically matched to water. It is specifically designed to transmit ultrasound in applications where the test part is partially or wholly immersed.
Applications:
Automated scanning On-line thickness gaging High speed flaw detection in pipe, bar, tube, plate, and other similar components Time-of-flight and amplitude based imaging Through transmission testing Material analysis and velocity measurements Usage Note : Transducers should not be submerged for periods exceeding 8 hours. Allow 16 hours of dry time to ensure the life of the unit.
Standard Case
A312S-SU-NK-CF1.00IN
Knurled case with Straight UHF connector (SU) Contact us for nonknurled case design and availability of other connector styles Frequencies ranging from 1.0 to 25 MHz
Frequency MHz 1.0 2.25 Nominal Element Size inches 0.50 0.50 0.375 0.25 0.50 3.5 0.375 0.25 0.50 5.0 7.5 10 0.375 0.25 0.50 0.50 0.375 0.25 0.50 15 0.375 0.25 20 25 0.25 0.125 0.25 mm 13 13 10 6 13 10 6 13 10 6 13 13 10 6 13 10 6 6 3 6 Unfocused Transducer Part Numbers ACCUSCAN-S A303S-SU A306S-SU A382S-SU A309S-SU A326S-SU A31OS-SU A32OS-SU A311S-SU A327S-SU A312S-SU A319S-SU A313S-SU CENTRASCAN C306-SU C325-SU C323-SU C382-SU C383-SU C384-SU C309-SU C326-SU C310-SU VIDEOSCAN V303-SU V306-SU V325-SU V323-SU V382-SU V383-SU V384-SU V309-SU V326-SU V31O-SU V32O-SU V311-SU V327-SU V312-SU V319-SU V328-SU V313-SU V317-SU V316-SU V324-SU
If a focus is required, select a focal length between min & max Point Target Focus (in inches)* Min 0.60 0.80 0.50 0.35 0.83 0.60 0.39 0.75 0.60 0.43 0.75 0.75 0.60 0.46 0.75 0.60 0.50 0.50 0.25 0.50 Max 0.80 1.90 1.06 0.45 2.95 1.65 0.70 4.20 2.35 1.00 6.30 8.40 4.75 2.10 11.75 7.10 3.15 4.20 1.00 5.25
For more technical information please refer to the following pages: Theory on Focusing page 44-46 Table of Near Field Distances page 48
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Frequency MHz
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Pencil Case
Small diameter, 2 (51 mm) long barrel improves access to difficult-to-reach areas Standard connector style is Straight UHF (SU)
Nominal Element Size inches 0.25 0.25 0.25 0.25 0.25 0.25 0.125 0.25 mm 6 6 6 6 6 6 3 6 Unfocused Transducer Part Numbers ACCUSCAN-S A310S-N-SU A312S-N-SU A313S-N-SU VIDEOSCAN V323-N-SU V384-N-SU V310-N-SU V312-N-SU V313-N-SU V317-N-SU V316-N-SU V324-N-SU If a focus is required, select a focal length between min & max Point Target Focus (in inches)* Min 0.35 0.30 0.43 0.46 0.50 0.50 0.25 0.50 Max 0.45 0.70 1.00 2.10 3.15 4.20 1.00 5.25 V316-N-SU
V3343
Note: All above side looking immersion transducers have straight Microdot connectors.
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Accuscan Paintbrush
Large scanning index is ideal for inspections of aluminum or steel plate Sensitivity uniformity of better than 1.5 dB is maintained across the transducer face (sensitivity peaks at the edges are also controlled)
-3dB -6dB
A334S-SU
Frequency MHz 2.25 3.5 5.0 7.5 10 2.25 3.5 5.0 7.5 10
-1.00
1.00
1.50 x 0.25
38 x 6
2.00 x 0.25
51 x 6
Reflector Mirrors
Directs sound beam when a straight-on inspection is not possible Standard mirrors provide a 90 reflection of the sound beam
Case Style Standard Slim Line Pencil Incident Angle () 45 45 45 F102 F132 F198 Part Numbers
F102 F132
F116 F198
F115
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Bubblers
Allows for immersion testing when complete immersion of parts is not desirable or possible Designed to maintain a consistent, low volume flow of water
B103AW
B103A
B103
Part Numbers
Case Style
MPF-B-0.5
0.300
B103
0.350
8.9
0.775
19.9
Standard SU
RBS-1 immersion tank is designed to simplify testing measurements using immersion techniques. It consists of a clear acrylic tank, a submersible pump and a transducer fixture in a single, portable unit. The pump feeds an adjustable stream of water to a bubbler mounted in the fixture, providing a water column to couple sound from an immersion transducer into the test piece. It is ideal for offline thickness measurements on metal, glass and plastic products such as small containers, pipe or tubing, sheets or plates or machined parts.
B103A
0.350
8.9
0.475
12.1
Standard SU
B103W
0.550
14
0.775
19.7
Standard SU
Pump
Up to 0.25 gallons (0.9 liters) per minute 115 or 230 V, 30 Watt (voltage range 90 to 135 VAC), 50 to 60 Hz Submersible (ground fault interrupter circuit recommended)
B103AW
0.550
14
0.475
12.1
B116 B117
0.100 1.375
2.5 34.4
*For more information on SU/RM case styles see page 24. For more information on Standard SU case styles see page 20.
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TOFD Transducers
Our time-of-flight diffraction transducers are highly damped longitudinal wave probes that offer excellent resolution in challenging TOFD applications. These highly sensitive composite element broadband transducers are available in frequencies from 2.25 MHz to 15 MHz and in sizes from 3 mm (0.25) to 12 mm (0.50). They are for use with specialized TOFD wedges designed to produce refracted longitudinal waves in steel.
Receiver
Backwall (+)
TOFD scan screen shot generated from an Olympus NDT MS5800 with Centrascan composite element TOFD transducers.
Case Type
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SIGNAL WAVEFORM
0.8
0.0
Advantages:
Heavily damped broadband design provides excellent time resolution Short wavelengths for superior flaw resolution capabilities Focusing allows for very small beam diameters Frequencies range from 20 MHz to 225 MHz
-0.4
-0.8
Applications:
High resolution flaw detection such as inspection for microporosity or microcracks C-scan imaging of surface breaking cracks or irregularities Thickness measurements of materials as thin as 0.0004 (0.010 mm)* Examination of ceramics and advanced engineering materials Materials analysis
*Thickness range depends on material, transducer, surface condition, temperature, and setup selected.
0
107 319 6dB
250.00 (MHz)
500.00
Contact transducers are available in frequencies up to 225 MHz. Performance is dependent on pulser/receiver and application. All transducers are manufactured on a special basis to customer specifications. Contact us to discuss applications.
V213-BA-RM V215-BC-RM
Frequency MHz 20
Delay sec 4.25 4.25 2.5 4.25 4.25 2.5 4.25 4.25 2.5 4.25 4.25 2.5 2.5 2.5 4.25 2.5 2.5
Transducer Part Numbers V212-BA-RM V212-BB-RM V212-BC-RM V213-BA-RM V213-BB-RM V213-BC-RM V214-BA-RM V214-BB-RM V214-BC-RM V215-BA-RM V215-BB-RM V215-BC-RM V2022 (BC) V2025 (BC) V2054 (BA) V2012 (BC) V2062
Delay Style BA BB BC Transducer Dimensions (in inches) (A) 0.72 0.34 0.34 (B) 0.81 0.44 0.44 (C) 1.00 0.81 0.63
V214-BB-RM
30
0.25 0.25 0.25 0.25 0.25 0.125 0.125 0.125 0.25 0.125 0.125 0.125 0.125
50
75 100 125
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V358-SU
Frequency MHz
Delay sec 4.25 2.5 4.25 4.25 4.25 2.25 4.25 4.25 4.25
Frequency MHz
Delay sec 19.5 19.5 19.5 19.5 19.5 9.4 19.5 19.5 19.5 19.5 19.5 19.5 9.4 10
Focal Length inches 0.50 0.75 1.00 1.75 2.00 0.20 0.50 0.50 0.75 0.50 0.50 1.00 0.20 0.25 mm 13 19 25 45 51 5 13 13 19 13 13 25 5 6
Transducer Part Numbers V390-SU/RM V3192 V3193 V3409 V3337 V3330* V3332 V3320 V3349 V3512 V3194 V3394 V3534* V3346
50
0.25 0.25 0.25 0.125 0.25 0.25 0.25 0.25 0.25 0.25 0.125
75 90
100
*Transducers create surface waves in steel, titanium and other materials with similar velocities. Please contact us for higher frequency. Lightweight High Frequency transducers are an alternative to the SU/RM case style transducers. They offer a smaller case width and lighter weight without sacrificing performance.
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AM2R-8X9-45
Transducer Part Number AM2R-8X9-45 AM2R-8X9-60 AM2R-8X9-70 AM2R-14X14-45 AM2R-14X14-60 AM2R-14X14-70 AM4R-8X9-45 AM4R-8X9-60 AM4R-8X9-70 AM5R-14X14-45 AM5R-14X14-60 AM5R-14X14-70 AM6S-3X4-45 AM6S-3X4-60 AM6S-3X4-70
Connector
Outline # 1 1 1 2 2 2 1 1 1 2 2 2 3 3 3
Lemo 00 Lemo 00 Lemo 00 Lemo 00 Lemo 00 Lemo 00 Lemo 00 Lemo 00 Lemo 00 Lemo 00 Lemo 00 Lemo 00 Microdot Microdot Microdot
DL2R-7X18
DL4R-3.5X10
Dual
Frequency MHz 2 2 2 4 4 4 28 Nominal Element Size mm 7 x 18 7 x 18 11 3.5 x 10 6 x 20 6 x 20 DL2R-7X18 DL2R-7X18-0 DL2R-11 DL4R-3.5X10 DL4R-6X20 DL4R-6X20-0 Transducer Part Number Focus mm 15 30 8 10 12 25 Typical Bandwidth (%) 50 50 48 45 48 48 Lemo 00 x 2 Lemo 00 x 2 Lemo 00 x 2 Lemo 00 x 2 Lemo 00 x 2 Lemo 00 x 2 4 4 5 5 4 4 Connector Outline #
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Contact
Frequency MHz 2 2 4 4 Nominal Element Size mm 10 24 10 24 CN2R-10 CN2R-24 CN4R-10 CN4R-24 Transducer Part Number Near Field mm 7.2 45 15.6 91 Typical Bandwidth (%) 85 85 85 85
PF2R-10
7
PF4R-24
Protected Face
Frequency MHz 1 2 2 4 4 Nominal Element Size mm 24 10 24 10 24 PF1R-24 PF2R-10 PF2R-24 PF4R-10 PF4R-24 Transducer Part Number Near Field mm 23 7.2 45 15.6 91 Typical Bandwidth (%) 45 45 45 35 30 Lemo 1 Lemo 00 Lemo 1 Lemo 00 Lemo 1 8 9 8 9 8 Connector Outline #
MRN-24
Cables
Description Transducer Type Dual Dual Dual Single Single Single Single Length meters Lemo 00 x 2 to Lemo 1 x 2 Lemo 00 x 2 to Lemo 00 x 2 BNC x 2 to Lemo 00 x 2 Lemo 00 to Lemo 00 Lemo 1 to Lemo 1 Lemo 1 to Lemo 00 Lemo 00 to BNC 2 2 2 2 2 2 2 L1CLD-316-2MK LCLD-316-2MK BCLD-316-2MK LCL-74-2M L1CL1-74-2M L1CL-74-2M LCB-74-2M pana@olympusNDT.com 29 Part Numbers
Also available is the AVG/DGS Binder, which contains a DGS diagram and specification sheet for each 8x9 angle beam, all dual element, and all protective face transducers. These diagrams are printed on splash and tear proof paper and housed in a six ring binder.
are available in an assortment of frequencies, sizes, and temperature capabilities to provide an off-the-shelf solution to most corrosion applications. Note: TP103 Certification is available at an additional charge by request.
D793 D7908 D790-RL D790 D795 D791-RM D790-SL MTD705 D7226 D792/D794
D7906-SM D790-SM
D798-LF
D799
D797-SM
Connector Type
Connector Location Straight Straight Straight Rt Angle Rt Angle Rt Angle Straight Rt Angle Straight Rt Angle Rt Angle Straight Rt Angle Rt Angle Rt Angle Straight Rt Angle Rt Angle
Range in Steel inches 0.040 - 20 0.040 - 20 0.040 - 20 0.040 - 20 0.040 - 20 0.040 - 20 0.020 - 1 0.020 - 1 0.030 - 2 0.030 - 2 0.150 - 25 0.150 - 25 0.028 - 4 0.028 - 4 0.028 - 4 0.028 - 4 0.040 - 20 0.040 - 0.75 mm 1.0 - 508 1.0 - 508 1.0 - 508 1.0 - 508 1.0 - 508 1.0 - 508 0.5 - 25 0.5 - 25 0.75 - 50 0.75 - 50 3.8 - 635 3.8 - 635 0.71 - 100 0.71 - 100 0.71 - 100 0.71 - 100 1.0 - 508 1.0 - 19
Temperature Range F -5 to 932 -5 to 932 -5 to 932 -5 to 932 -5 to 932 -5 to 752 32 to 122 32 to 122 32 to 122 32 to 122 -5 to 752 -5 to 752 -5 to 300 -5 to 300 -5 to 300 -5 to 300 -5 to 300 32 to 122 C -20 to 500 -20 to 500 -20 to 500 -20 to 500 -20 to 500 -20 to 400 0 to 50 0 to 50 0 to 50 0 to 50 -20 to 400 -20 to 400 -20 to 150 -20 to 150 -20 to 150 -20 to 150 -20 to 150 0 to 50
Wand
Lemo Potted Microdot Potted Potted Potted Potted Potted Microdot Potted Potted Potted Microdot Potted Lepra/Con
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Transducer Type
Range in Steel inches 0.02 - 0.400 0.02 - 0.400 0.02 - 0.400 0.040 - 2.0 0.040 - 1.5 Steel: 0.020 - 0.50 mm 0.5 - 10 0.5 - 10 0.5 - 10 1.0 - 50 0.71 - 37 Steel: 0.5 - 12
M2017
20
0.250
6.35
Microdot
Right Angle Oxide: 0.010 - 0.050 Steel: 0.020 - 0.50 Oxide: 0.25 - 1.25 Steel: 0.5 - 12
32 to 122
0 to 50
2127
M2091
20
0.250
6.35
Microdot
Right Angle Oxide: 0.006 - 0.050 Oxide: 0.150 - 1.25 2.0 - 125
32 to 122
0 to 50
2127
E110-SB
1.25
28.5
BNC
Straight
0.080 - 5
32 to 176
0 to 80
* Compatible with MG2-XT and MG2-DL Adaptor required for E110 (part number 1/2XA/E110).
Cable Type
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Special Transducers
Combination Longitudinal/ Shear Mode Transducers
These transducers generate simultaneous longitudinal waves and shear waves in either single element, dual element or three element arrangement. They can be custom designed for different frequencies and element sizes.
Note: Please replace X.XX" with the standard focal length of your choice. Due to the fact that polymer transducers are inherently broadband, their center frequency may be lower than the frequency indicated on the transducer
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Test Blocks
Calibration and/or Reference Blocks should be used in every application. Standard blocks are available for angle beam calibrations and thickness calibrations of common materials. Blocks manufactured from 1018 steel, 304 stainless steel, or 7075-T6 aluminum are commonly in stock (other materials require special quotes for price and delivery) Contact us for more information regarding materials not listed, blocks not listed, or custom blocks
Calibration Blocks
All blocks are checked dimensionally using measuring equipment traceable to the National Institute of Standards and Technology, NIST. The most commonly required calibration blocks are listed below.
Type ASTM E164 Calibration IIW-Type Block US Air Force IIW-2 Calibration Block RC AWS Block SC AWS Block DC AWS Block DSC AWS Block DS AWS Block 30FBH Resolution Reference Block NAVSHIPS Block ASTM E164 MAB Block ISO 7963 Steel Part Number TB7541-X TB1054-X TB5939-X TB7543-X TB7545-X TB7547-X TB7549-X TB7551-X TB7160-X TB7567-X TB7150-X TB1065-X Description Meets AASHTO and AWS Type 1 block requirements. Calibrates distance and sensitivity settings. Measure refracted angle and sound exit point of angle beam transducers. U.S. customary units (inches). Metric Units IIW-type block per U.S. Air Force NDI Manual T.O. 33B -1-1. Includes 2" and 4" radius cutouts for distance calibration. No. 3, No. 5 and No. 8 side drilled holes, and distance calibration marks to the 2" hole. Determining resolution capabilities of angle beam transducers per AWS and AASHTO requirements. Sensitivity and refracted angle calibration per AWS and AASHTO requirements. Distance and beam index calibration for angle beam transducers per AWS and AASHTO requirements. Distance, sensitivity, refracted angle and beam index calibration for angle beam transducers per AWS and AASHTO requirements. Calibration block for horizontal linearity and dB accuracy procedures per AWS and AASHTO requirements. Evaluate near surface resolution and flaw size/depth sensitivity of UT equipment. No. 3, No. 5 and No. 8 ASTM flat bottom holes at ten metal travel distances from 0.050" to 1.250". Contains six No. 3 side drilled holes. Used for distance-amplitude calibration per NAVSHIPS 0900-006 -3010. Miniature Angle Beam (ROMPAS) Block. Distance, beam index, refracted angle and sensitivity calibration. One inch thick. Miniature Angle Beam Block Distance, beam index, refracted angle and sensitivity calibration. 25 mm thick. Hardwood Case F129 F129 F129 F157 F158 F159 F160 F161 Included F162 F197 F197
Replace the X in the part number with the appropriate number listed below to signify block material: 1 = 1018 Steel 2 = 4340 Steel 4 = 7075-T6 Aluminum 5 = 304 Stainless Steel 8 = 6-4 Titanium
TB7567-1
TB7543-1
TB5939-1 TB1065-1
TB7549-1 TB7150-1
TB7541-1
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Reference Blocks
We offer commonly used sets of reference blocks recommended by ASTM standards. These sets are all manufactured to ASTM E127 and ASTM E428 physical dimensions requirements. All reference blocks are provided with an ultrasonic response curve. We can provide, by
Type of Set* Distance-Area Amplitude Set Area-Amplitude Set Part Number TB6100-X TB6200-X
special order, materials not listed and individual reference blocks. Contact us for more information regarding materials not listed, custom calibration blocks, or quotations on blocks not listed in this section.
Description of Set Set of 10 ASTM E 127 (7075 Alum) or ASTM E 428 (all other materials) basic set consisting of 3/64 at 3", 5/64 at 1/8", 1/4", 1/2", 3/4", 1-1/2", 3", and 6", and 8/64 at 3" and 6". This set is used for determining Dead Zone, Sensitivity, Distance and Area Amplitude Linearity Measurement. Set of 8 ASTM E 127 (7075 Alum) or ASTM E 428 (all other materials) Area Amplitude Set consisting of 1/64, 2/64, 3/64, 4/64, 5/64, 6/64, 7/64, and 8/64 Flat Bottom Holes at 3". This set is used to determine the relationship between flaw size and echo amplitude by comparing signal response. Set of 19 ASTM E 127 (7075 Alum) or ASTM E 428 (all other materials) Distance Amplitude Set. All Flat Bottom Holes are the same and metal travel distances are 1/16", 1/8", 1/4", 3/8", 1/2", 5/8", 3/4", 7/8", 1", 1-1/4", 1-3/4", 2-1/4", 2-3/4" 3-1/4", 3-3/4", 4-1/4", 4-3/4", 5-1/4", and 5-3/4". This set is used to determine the relationship between metal distance and signal amplitude by comparing signal responses obtained. 1/16" 1/8" 1/4" 3/8" 1/2" 5/8" 3/4" 7/8" 1" 1-1/4" 1-3/4" 2-1/4" 2-3/4" 3-1/4" 3-3/4" 4-1/4" 4-3/4" 5-1/4" 5-3/4"
TB6303-X
Set of 9 ASTM E 127 (7075 Alum) or ASTM E 428 (all other materials) consisting of 1/64 at 3"9, 2/64 at 3", and 5/64 at 1/8", 1/4" 3/8", 1/2", 3/4" 1" and 1-1/2", and 1 ASTM E 317 Horizontal and Vertical Linearity Block used to evaluate the sensitivity, entry surface resolution, and horizontal and vertical linearity characteristics of UT equipment.
Replace the X in the part number with the appropriate number listed below to signify block material: 1 = 1018 Steel 2 = 4340 Steel 4 = 7075-T6 Aluminum 5 = 304 Stainless Steel 8 = 6-4 Titanium
2214E
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Cables
Select from a variety of cable grades to meet your specific application needs Standard lengths 3 (1 m), 4 (1.2 m), 6 (1.8 m). When ordering, replace the x in the part number with the desired cable length in feet Custom cable lengths are available; please specify when ordering Part numbering prefix indicates connector style for both ends of the cable All cables are 50 ohms impedance unless otherwise specified Contact us for special or customized cables
Standard
Cable Part Numbers BCB-58-x BCB-74-x BCM-74-x BCMA-74-x BCRM-74-x BCU-58-x BCU-62-x FLCB-74-x LCB-74-x LCM-74-x LCU-74-x L1CB-58-x L1CM-74-x L1CU-74-x L1CU-74-x UCM-74-x UCU-58-x Fits Connector Style Fits BNC to BNC Fits BNC to BNC Fits BNC & Microdot Fits BNC & Microdot without Boot Fits BNC & Right Angle Microdot Fits BNC to UHF Fits BNC to UHF Fits Female Lemo & BNC Fits Small Lemo 00 & BNC Fits Small Lemo 00 & Microdot Fits Small Lemo 00 & UHF Fits Large Lemo 1 & BNC Fits Large Lemo 1 & Microdot Fits Large Lemo 1 & UHF Fits Large Lemo 1 & UHF
Waterproof (W)
Specially designed proprietary waterproof UHF connector provides a waterproof connection good to depths of about 150 feet (50 m) in fresh water
Cable Part Numbers BCM-74-x W BCRM-74-x W BCU-58-x W BCU-62-x W BCU-74-x W LCM-74-x W LCU-74-x W L1CU-74-x W 36 Fits Connector Style Fits BNC to Waterproof Microdot Fits BNC to Waterproof Right Angle Microdot Fits BNC to Waterproof UHF Fits BNC to Waterproof UHF Fits BNC to Waterproof UHF Fits Small Lemo 00 to Waterproof Microdot Fits Small Lemo 00 to Waterproof UHF Fits Large Lemo 1 to Waterproof UHF
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Standard
Heavy Duty
Armored
RG188 Heavy Duty Teflon Coated (HD) Microdot Handle 3" Connector
RG188 Heavy Duty Armored Super Flexible Silicone (HDAS) Microdot Connector
Dual
Single cable design with two connectors at each end to fit dual element transducers
Cable Part Numbers BCMD-74-6 LCMD-74-6 L1CMD-74-6 BCMD-316-5F L1CMD-316-5F BCLPD-78-5 L1CLPD-78-5 Fits Connector Style Dual BNC to Microdot Dual Small Lemo 00 to Microdot Dual Large Lemo 1 to Microdot Dual BNC to Microdot Dual Large Lemo 1 to Microdot Dual BNC to Lepra/Con Dual Large Lemo 1 to Lepra/Con Compatible With Standard Dual Transducer Flush Case Dual Transducer MTD-705 Transducer
Fits Connector Style Fits BNC to BNC Fits BNC to Microdot Fits BNC to UHF Fits Small Lemo 00 to BNC Fits Small Lemo 00 to Microdot
Adaptors
Part Numbers F108 F195 F202 F206 F267 BF-BF BM-BM BM-UF L1F-BM L1M-BF LM-BF LF-BM MM-UMW UM-BF LF-UM MM-UFW Fits Connector Style Right Angle UHF Male to UHF Female, waterproof 45 UHF Female to UHF Male Active UHF Female to Passive UHF Male/Active Right Angle Microdot Female (see page 27). UHF to Flange Right Angle UHF Female to UHF Male, waterproof BNC Female to BNC Female BNC Female to BNC Female BNC Male to UHF Female Lemo 1 Female to BNC Male Lemo 1 Male to BNC Female Lemo 00 Male to BNC Female Lemo 00 Female to BNC Male Microdot Male to UHF Male, waterproof UHF Male to BNC Female Lemo 00 Female to UHF Male Microdot Male to UHF Female, waterproof L1M-BF
LF-BM
F195
F108
UM-BF MM-UMW
LM-BF
F267
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Transducer Excitation ............................................................. 46 Cables ................................................................................46-47 Acoustic Properties of Materials............................................. 48 Near Field Distance of Flat Transducers in Water .................. 48
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Technical Notes
The Technical Notes section is designed to provide a brief overview of the ultrasonic principles important to transducer application and design. The Technical Notes are organized in the following sections: Eqn. 1
1. Basic Ultrasonic Principles 2. Advanced definitions and formulas 3. Design characteristics of transducers 4. Transducer specific principles 5. Transducer excitation guidelines 6. Cables
The velocity of ultrasound (c) in a perfectly elastic material at a given temperature and pressure is constant. The relation between c, f, l and T is given by Equations (2) and (3): Eqn. 2 l c f T = = = = Eqn. 3 Wavelength Material Sound Velocity Frequency Period of time
Table 1 on page 48 lists the longitudinal and shear wave velocities of materials that are commonly tested with ultrasonics.
The most common methods of ultrasonic examination utilize either longitudinal waves or shear waves. Other forms of sound propagation exist, including surface waves and Lamb waves. The longitudinal wave is a compressional wave in which the particle motion is in the same direction as the propagation of the wave. The shear wave is a wave motion in which the particle motion is perpendicular to the direction of the propagation. Surface (Rayleigh) waves have an elliptical particle motion and travel across the surface of a material. Their velocity is approximately 90% of the shear wave velocity of the material and their depth of penetration is approximately equal to one wavelength. Plate (Lamb) waves have a complex vibration occurring in materials where thickness is less than the wavelength of ultrasound introduced into it. Figure (3) provides an illustration of the particle motion versus the direction of wave propagation for longitudinal waves and shear waves. Fig. 3
Ultrasonic vibrations travel in the form of a wave, similar to the way light travels. However, unlike light waves, which can travel in a vacuum (empty space), ultrasound requires an elastic medium such as a liquid or a solid. Shown in Figure (2) are the basic parameters of a continuous wave (cw). These parameters include the wavelength (l) and the period (T) of a complete cycle. Fig. 2
Longitudinal Wave Direction of Particle Motion Direction of Wave Propagation Shear Wave
e. Applying Ultrasound
The number of cycles completed in one second is called frequency (f) and is measured in Hertz (Hz), some examples follow; 1 cycle/second= 1Hz 1000 cycles/second= 1kHz 1,000,000 cycles/second= 1MHz The time required to complete a full cycle is the period (T), measured in seconds. The relation between frequency and period in a continuous wave is given in Equation (1). 40 www.olympusNDT.com
Ultrasonic nondestructive testing introduces high frequency sound waves into a test object to obtain information about the object without altering or damaging it in any way. Two basic quantities are measured in ultrasonic testing; they are time of flight or the amount of time for the sound to travel through the sample, and amplitude of received signal. Based on velocity and round trip time of flight through the material the material, thickness can be calculated as follows: Eqn. 4 T c t = = = Material Thickness Material Sound Velocity Time of Flight
Technical Notes
Measurements of the relative change in signal amplitude can be used in sizing flaws or measuring the attenuation of a material. The relative change in signal amplitude is commonly measured in decibels. Decibel values are the logarithmic value of the ratio of two signal amplitudes. This can be calculated using the following equation. Some useful relationships are also displayed in the table below; Eqn. 5
LOWER UPPER
Figure (5) illustrates peak frequency, upper and lower -6 dB frequencies and MHz bandwidth measurements. Fig. 5
PEAK
-6dB
Amplitude
dB = A1 = A2 =
Ratio
dB
Frequency (MHz)
BANDWIDTH
1.4142 2 4 10 100
3 6 12 20 40
The relation between MHz bandwidth and waveform duration is shown in Figure (6). The scatter is wider at -40 dB because the 1% trailing end of the waveform contains very little energy and so has very little effect on the analysis of bandwidth. Because of the scatter it is most appropriate to specify waveforms in the time domain (microseconds) and spectra in the frequency domain. Fig. 6
(Microseconds) 10 100
Waveform Duration
-40dB -14dB
.01
.1
.1
10
100
The approximate relations shown in Figure (6) can be used to assist in transducer selection. For example, if a -14 dB waveform duration of one microsecond is needed, what frequency transducer should be selected? From the graph, a bandwidth of approximately 1 to 1.2 MHz corresponds to approximately 1 microsecond -14 dB waveform duration. Assuming a nominal 50% fractional bandwidth transducer, this calculates to a nominal center frequency of 2 to 2.4 MHz. Therefore, a transducer of 2.25 MHz or 3.5 MHz may be applicable.
The acoustic impedance of a material is the opposition to displacement of its particles by sound and occurs in many equations. Acoustic impedance is calculated as follows: Eqn. 6 Z c r = = = Acoustic Impedance Material Sound Velocity Material Density
-14dB
The boundary between two materials of different acoustic impedances is called an acoustic interface. When sound strikes an acoustic interface at normal incidence, some amount of sound energy is reflected and some amount is transmitted across the boundary. The dB loss of energy on transmitting a signal from medium 1 into medium 2 is given by:
Amplitude
Eqn. 7a
WAVEFORM DURATION
Time (Microseconds)
Z1 = Z2 =
Technical Notes
The dB loss of energy of the echo signal in medium 1 reflecting from an interface boundary with medium 2 is given by: Eqn. 7b For example: The dB loss on transmitting from water (Z = 1.48) into 1020 steel (Z = 45.41) is -9.13 dB; this also is the loss transmitting from 1020 steel into water. The dB loss of the backwall echo in 1020 steel in water is -0.57 dB; this also is the dB loss of the echo off 1020 steel in water. The waveform of the echo is inverted when Z2<Z1. Finally, ultrasound attenuates as it progresses through a medium. Assuming no major reflections, there are three causes of attenuation: diffraction, scattering and absorption. The amount of attenuation through a material can play an important role in the selection of a transducer for an application. ZB Fz ZE D = = = = Beginning of the Focal Zone Focal Zone End of the Focal Zone Element Diameter Fig. 8
c. Sound Field
The sound field of a transducer is divided into two zones; the near field and the far field. The near field is the region directly in front of the transducer where the echo amplitude goes through a series of maxima and minima and ends at the last maximum, at distance N from the transducer. Fig. 7
Note that the distance to the maximum echo from a flat plate target and the maximum echo from the point target are not the same, although both will occur within the calculated -6 dB focal zone. Beam Diameter A transducers sensitivity is affected by the beam diameter at the point of interest. The smaller the beam diameter, the greater the amount of energy is reflected by a flaw. The -6 dB pulse-echo beam diameter at the focus can be calculated with Equation 9 or 9a. For a flat transducer use Equation 9a with SF = 1 Eqn. 9 Eqn. 9a BD F c f D SF = = = = = = Beam Diameter Focal Length Material Sound Velocity Frequency Element Diameter Normalized Focal Length (Eqn. 14)
The location of the last maximum is known as the near field distance (N or Y0+) and is the natural focus of the transducer. The far field is the area beyond N where the sound field pressure gradually drops to zero. Because of the variations within the near field it can be difficult to accurately evaluate flaws using amplitude based techniques. The near field distance is a function of the transducer frequency, element diameter, and the sound velocity of the test material as shown by Equation 8: Eqn. 8 N D f c l = = = = = Eqn. 8a Near Field Distance Element Diameter Frequency Material Sound Velocity Wavelength
Focal Zone The starting and ending points of the focal zone are located where the on-axis pulse-echo signal amplitude drops to - 6 dB of the amplitude at the focal point. The length of the focal zone is given by Equation 10: Eqn. 10 FZ N SF = = = Focal Zone Near Field Normalized Focal Length (Eqn. 14)
Figure (9) shows the normalized beginning (SB) and ending (SE) point of the -6 dB focal zone versus the focusing factor. Fig. 9 -6 dB Focal Zone
(Table 2 on page 48 lists the near field distances in water for many combinations of transducer frequency and element diameter.)
There are a number of sound field parameters that are useful in describing the characteristics of a transducer. In addition to the near field, knowledge of the beam width and focal zone may be necessary in order to determine whether a particular transducer is appropriate for a given inspection. Figure (8) gives a graphical representation of these parameters:
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Technical Notes
Beam Spread and Half Angle All ultrasonic beams diverge. In other words, all transducers have beam spread. Figure (10) gives a simplified view of a sound beam for a flat transducer. In the near field, the beam has a complex shape that narrows. In the far field the beam diverges. Fig. 10 transducer that is lower in resolution due to a longer waveform duration, but may be higher in signal amplitude or greater in sensitivity.
d. Wear Plate
The basic purpose of the transducer wear plate is to protect the transducer element from the testing environment. In the case of contact transducers, the wear plate must be a durable and corrosion resistant material in order to withstand the wear caused by use on materials such as steel. For immersion, angle beam, and delay line transducers the wear plate has the additional purpose of serving as an acoustic transformer between the high acoustic impedance of the active element and the water, the wedge or the delay line all of which are of lower acoustic impedance. This is accomplished by selecting a matching layer that is 1/4 wavelength thick (l/4) and of the desired acoustic impedance (the active element is nominally 1/2 wavelength). The choice of the wear surface thickness is based upon the idea of superposition that allows waves generated by the active element to be in phase with the wave reverberating in the matching layer as shown in Figure (4). When signals are in phase, their amplitudes are additive, thus a greater amplitude wave enters the test piece. Figure (12) shows the active element and the wear plate, and when they are in phase. If a transducer is not tightly controlled or designed with care and the proper materials, and the sound waves are not in phase, it causes a disruption in the wavefront. Fig. 12
For flat transducers as shown in Figure (10), the - 6 dB pulse-echo beam spread angle is given by Equation (11): Eqn. 11 a/2 = Half Angle Spread between -6 dB points
It can be seen from this equation that beam spread from a transducer can be reduced by selecting a transducer with a higher frequency or a larger element diameter or both.
The active element, which is piezo or ferroelectric material, converts electrical energy such as an excitation pulse from a flaw detector into ultrasonic energy. The most commonly used materials are polarized ceramics which can be cut in a variety of manners to produce different wave modes. New materials such as piezo polymers and composites are also being employed for applications where they provide benefit to transducer and system performance.
c. Backing
The backing is usually a highly attenuative, high density material that is used to control the vibration of the transducer by absorbing the energy radiating from the back face of the active element. When the acoustic impedance of the backing matches the acoustic impedance of the active element, the result will be a heavily damped transducer that displays good range resolution but may be lower in signal amplitude. If there is a mismatch in acoustic impedance between the element and the backing, more sound energy will be reflected forward into the test material. The end result is a
DISTANCE (INCHES)
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Technical Notes
b. Angle Beam Transducers
Fig. 16 Angle beam transducers use the principles of refraction and mode conversion to produce refracted shear or longitudinal waves in the test material as shown in Figure (14). Fig. 14
The incident angle necessary to produce a desired refracted wave (i.e. a 45 shear wave in steel) can be calculated from Snells Law as shown in Equation (12). Because of the effects of beam spread, this equation doesnt hold at low frequency and small active element size. Contact us for details concerning these phenomena. Eqn. 12 qi qrl qrs ci crl crs = = = = = = Incident Angle of the Wedge Angle of the Refracted Longitudinal Wave Angle of the Refracted Shear Wave Velocity of the Incident Material (Longitudinal) Material Sound Velocity (Longitudinal) Velocity of the Test Material (Shear)
Many AWS inspections are performed using refracted shear waves. However, grainy materials such as austenitic stainless steel may require refracted longitudinal waves or other angle beam techniques for successful inspections.
Delay line transducers are single element longitudinal wave transducers used in conjunction with a replaceable delay line. One of the reasons for choosing a delay line transducer is that near surface resolution can be improved. The delay allows the element to stop vibrating before a return signal from the reflector can be received. When using a delay line transducer, there will be multiple echoes from end of the delay line and it is important to take these into account. Another use of delay line transducers is in applications in which the test material is at an elevated temperature. The high temperature delay line options listed in this catalog (page 16, 17, 19) are not intended for continuous contact, they are meant for intermittent contact only.
Figure (15) shows the relationship between the incident angle and the relative amplitudes of the refracted or mode converted longitudinal, shear, and surface waves that can be produced from a plastic wedge into steel. Fig. 15
d. Immersion Transducers
Immersion transducers offer three major advantages over contact transducers: Uniform coupling reduces sensitivity variations. Reduction in scan time due to automated scanning. Focusing of immersion transducers increases sensitivity to small reflectors. Focusing Configurations Immersion transducers are available in three different configurations: unfocused (flat), spherically (spot) focused, and cylindrically (line) focused. Focusing is accomplished by either the addition of a lens or by curving the element itself. The addition of a lens is the most common way to focus a transducer. An unfocused transducer may be used in general applications or for penetration of thick materials. A spherically focused transducer is commonly used to improve sensitivity to small flaws and a cylindrical focus is typically used in the inspection of tubing or bar stock. Examples of spherical and cylindrical focusing are shown in Figure (17).
Angle beam transducers are typically used to locate and/or size flaws which are oriented non-parallel to the test surface. Following are some of the common terms and formulas used to determine the location of a flaw.
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Technical Notes
Fig. 17
Cylindrical
Spherical
it is typically specified for water. Since most materials have a higher velocity than water, the focal length is effectively shortened. This effect is caused by refraction (according to Snells Law) and is illustrated in Figure (18). Fig. 18
By definition, the focal length of a transducer is the distance from the face of the transducer to the point in the sound field where the signal with the maximum amplitude is located. In an unfocused transducer, this occurs at a distance from the face of the transducer which is approximately equivalent to the transducers near field length. Because the last signal maximum occurs at a distance equivalent to the near field, a transducer, by definition, can not be acoustically focused at a distance greater than its near field. Focus may be designated in three ways:
This change in the focal length can be predicted by Equation (13). For example, given a particular focal length and material path, this equation can be used to determine the appropriate water path to compensate for the focusing effect in the test material. Eqn. 13
FPF (Flat Plate Focus) - For an FPF focus, the lens is designed to produce a maximum pulse/echo response from a flat plate target at the distance indicated by the focal length PTF (Point Target Focus) - For a PTF focus, the lens is designed to produce a maximum pulse/echo response from a small ball target at the distance indicated by the focal length OLF (Optical Limit Focus) - The OLF designation indicates that the lens is designed according to the lens makers formula from physical optics and without reference to any operational definition of focal length. The OLF designation describes the lens and ignores diffraction effects. When focusing a transducer, the type of focus (spherical or cylindrical), focal length, and the focal target (point or flat surface) need to be specified. Based on this information, the radius of curvature of the lens for the transducer which varies based on above parameters, can be calculated . When tested, the measured focal length will be off of the target specified. There are limitations on focal lengths for transducers of a given frequency and element diameter for a particular focal designation. The maximum practical focal length for a flat plate focus (FPF) is 0.6 times the near field length, and for a point target focus (PTF) the maximum practical focal length is 0.8 times the near field length. Optical limit focus (OLF) focal length is not specifically constrained, but it should be understood that the actual maximum response point from a given target may not correspond to the distance indicated by the OLF focal length. FPF and PTF transducers with focal lengths beyond these maximums, but less than the near field length, will usually be weakly focused units with only a small increase in sensitivity at the focal point. As a practical matter, there may be no functional advantage to a weakly focused transducer over a flat, unfocused transducer. In addition to acoustic limitations on maximum focal lengths, there are mechanical limitations on minimum focal lengths. Consult us for detailed information on focusing parameters. Table 2 on page 48 lists the near field distances as well as the minimum and maximum practical focal lengths for common frequency-element diameter combinations. Consult us for detailed information in focusing parameters. Focal Length Variations due to Acoustic Velocity and Geometry of the Test Part The measured focal length of a transducer is dependent on the material in which it is being measured. This is due to the fact that different materials have different sound velocities. When specifying a transducers focal length
WP MP F ctm cw
= = = = =
Water Path Material Depth Focal Length in Water Sound Velocity in the Test Material Sound Velocity in Water
In addition, the curvature of surface of the test piece can affect focusing. Depending on whether the entry surface is concave or convex, the sound beam may converge more rapidly than it would in a flat sample or it may spread and actually defocus. Focusing Gain Focused immersion transducers use an acoustic lens to effectively shift the location of the Y0+ point toward the transducer face. The end result can be a dramatic increase in sensitivity. Figure (19) illustrates the relative increase in signal amplitude from small defects due to focusing where SF is the normalized focal length and is given by Equation (14). The amplitude from a small defect cannot exceed the echo amplitude from a flat plate. Eqn. 14 SF F N Fig. 19 = = = Normalized Focal Length Focal Length Near Field
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Technical Notes
For example, the chart can be used to determine the increase in on-axis pulse-echo sensitivity of a 2.25 MHz, 1.0" element diameter transducer that is focused at 4 inches. The near field length of this transducer is 9.55", and the normalized focal length is 0.42 (4.0"/9.55"). From the chart it can be seen that this will result in an increase in sensitivity of approximately 21 dB. Focusing gain (dB) for cylindrical focuses can be estimated as being 3/4 of the gain for spherical focuses. Eqn. 19 Eqn. 20
Normal Incidence Shear Wave transducers incorporate a shear wave crystal in a contact transducer case. Rather than using the principles of refraction, as with the angle beam transducers, to produce shear waves in a material, the crystal itself produces the shear wave. Typically these transducers are used to make shear velocity measurements of materials. This measurement, along with a longitudinal velocity measurement can be used in the calculation of Poissons Ratio, Youngs Modulus, and Shear Modulus. These formulas are listed below for reference. Eqn. 15
Following is an example of how to use the above equations to calculate a duty cycle and number of cycles for a V310-SU transducer. V310-SU Assuming: 5.0M Hz, 0.25" element diameter, unfocused 100 V Peak-to-Peak 50 ohm nominal impedance at the transducer input impedance (Note: This value will vary from transducer to transducer and should be measured. An impedance plot can be ordered at the time of purchase if necessary.) -45 Phase Angle 5 kHz Rep Rate Step 1: Calculate Vrms Vrms=1/2(0.707)Vp-p Vrms=1/2(0.707)(100)=35.35 V Step 2: Rearrange Equation (19) to solve for the Duty Cycle. Use 0.125 W as Ptot, as this is the maximum recommended for any transducer. Duty Cycle = = Z*Ptot/(Vrms)2*cos(phase angle) (50)(0.125)/(35.35)2*(cos -45)
Eqn. 16
Eqn. 17 s VL VT r E G = = = = = = Poissons Ratio Longitudinal Velocity Shear (Transverse) Velocity Material Density Youngs Modulus Shear Modulus
= 0.007s/s This means 7 milliseconds of excitation in every 1000 milliseconds. Step 3: Number of cycles in the burst can now be calculated from Equation (20). No. Of Cycles in Burst = (Freq.)(Duty Cycle) Rep Rate = (5*106)*(0.007)/(5*103) = 7
Because shear waves do not propagate in liquids, it is necessary to use a very viscous couplant when making measurements with these. When using this type of transducer in a through transmission mode application, it is important that direction of polarity of each of the transducers is in line with the other. If the polarities are 90 off, the receiver may not receive the signal from the transmitter.
6. CABLES
The inside of a cable is made of three main components. They are the conductor, the dielectric, and shield/braid. These components are then surrounded by an outer protective jacket. Figure (20) shows a cross-sectional view of a typical cable. The conductor acts as the positive connection of the cable while the shield acts as the ground. The dielectric isolates the conductor from the shield. Fig. 20
5. TRANSDUCER EXCITATION
As a general rule, all of our ultrasonic transducers are designed for negative spike excitation. The maximum spike excitation voltages should be limited to approximately 50 volts per mil of piezoelectric transducer thickness. Low frequency elements are thick, and high frequency elements are thin. A negative-going 600 volt fast rise time, short duration, spike excitation can be used across the terminals on transducers 5.0 MHz and lower in frequency. For 10 MHz transducers, the voltage used across the terminals should be halved to about 300 volts as measured across the terminals. Although negative spike excitation is recommended, continuous wave or tone burst excitations may be used. However there are limitations to consider when using these types of excitation. First, the average power dissipation to the transducer should not exceed 125 mW to avoid overheating the transducer and depoling the crystal. Since total average power depends on a number of factors such as voltage, duty cycle and transducer electrical impedance, the following equations can be used to estimate the maximum excitation duration as well as the number of cycles in a burst to stay within the total power limitation: Eqn. 18
Most cables have one shielding/braided layer. However, to better prevent electrical interference from the environment double shielded cables have an additional shielding/braided layer in contact with the other.
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Technical Notes
The following is a list of standard cable grades we offer: Type Grade Impedance Nominal Diameter inches 15 25 58 62 74 188 316 Low Impedance Low Impedance RG58/U RG62/U RG174/U RG188/U RG316/U 15 ohms 25 ohms 50 ohms 93 ohms 50 ohms 50 ohms 50 ohms 0.11 0.10 0.20 0.24 0.11 0.11 N/A
RG/U is the abbreviation for radio guide, universal in the military, RG is the designation for coaxial cable and U stands for general utility. Most of the cables used in ultrasonic NDT have military RG numbers that define the materials, dimensions, and electrical characteristics of the cables. The characteristic impedance of a coaxial cable is determined by the ratio for the inner diameter of the outer conductor (D) to the outer diameter of the inner conductor (d) and by the dielectric constant (E) of the insulating material between the conductors. Eqn. 21 The characteristic impedance can also be calculated form the capacitance (C) and the inductance (L) per unit length of cable Eqn. 22 The most common values for coaxial cables are 50 ohm, 75 ohm, and 95 ohm. Note that the actual input impedance at a particular frequency may be quite different from the characteristics impedance of the cable due to the impedance of the source and load. In ultrasonics, on transmit the source is the pulser and the load is the transducer; on receive the source is the transducer and the load is the receiver. The complex impedance of the pulser and the transducers will reflect some of the electrical energy at each end of the cable. The amount of reflection is determined by the length of the cable, the frequency of the RF signal, and the electrical impedance of the cable and its termination. In ultrasonic NDT the effect of the cable is most practically determined by experimenting with the shorter and longer cables, with cables of differing impedance, and by placing a 50 ohm feed-through attenuator at the pulser/receiver jack.
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Technical Notes
Table Acoustic Properties of Materials
Material
Acrylic resin (Perspex) Aluminum Beryllium Brass, naval Cadmium Columbium Copper Glycerine Gold Inconel Iron Iron, cast (slow) (fast) Lead Manganese Mercury Molybdenum Motor Oil (SAE 20 or 30) Nickel, pure Platinum Polyamide, (nylon, Perlon) (slow) (fast) Polystyrene Polyvinylchloride, PVC, hard Silver Steel, 1020 Steel, 4340 Steel, 302 austenitic stainless Steel, 347 austenitic stainless Tin Titanium, Ti 150A Tungsten Uranium Water (20C) Zinc Zirconium 0.087 0.102 0.092 0.094 0.142 0.232 0.230 0.223 0.226 0.131 0.240 0.204 0.133 0.058 0.164 0.183
-5
N (inches)
4.757 2.661 2.095 1.164 9.559 5.366 4.235 2.372 1.043 21.534 12.099 9.554 5.364 2.374 1.329 0.584 14.868 8.350 3.699 2.073 0.914 21.243 11.932 5.287 2.965 1.309 17.900 7.933 42.490 23.868 10.579 5.934 2.622 15.870 8.902 3.935 5.247 1.290 6.559
1.0
2.25
3.5
5.0
7.5
10
15
20 25
* Conversion Factor: 1 m/s = 3.937 x 10 in/S Source: Nondestructive Testing Handbook 2nd Edition Volume 7 Ultrasonic Testing ASNT 1991 ed Paul McIntire
** Panametrics Standard Case Style, Large Diameter Case Style, Slim Line Case Style, and Pencil Case Style Immersion Transducers with straight connectors (see pages 20-24) can be focused between the Minimum and Maximum Point Target Focal (PTF) distance limits listed in Table 2. Please consult Panametrics before ordering a transducer focused outside these limits. Consideration should be given to attenuation effects which increase linearity and with the square of frequency and the square of bandwidth. In applications where long water paths are required the effects of frequency dependent attenuation should be checked per ASTM E 1065 Annex A7. It is advisable to consider the effects of frequency dependent attenuation if the focal distance equals or exceeds the following values: Frequency Focal Length MHz 5.0 7.5 10 15 20 25 30 inches 13 6 3.5 1.5 0.8 0.5 0.4
The near field values in this table have been determined using the following equation:
Note that equations 8 and 8a on page 42 were derived from this expression. The calculations were carried out assuming an ultrasonic velocity in water of 0.586 x 105 in/sec at 22C and using the actual transducer element diameters. It should be noted that the actual transducer element diameters are slightly smaller than the nominal element diameters listed in the tables in the catalog. The minimum and maximum practical focal lengths have been calculated by considering the acoustic and mechanical limitations of each configuration. These limitations are a function of transducer frequency, element diameter, and case dimensions. There may be exceptions to the limits listed in the table.
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El. Venizelou 7 & Delfon, Metamorfosi 14452 Athens, Greece tel: +30 210 2846 801-4, fax: +30 210 2846 805 sales@envirocoustics.gr, www.envirocoustics.gr