Dakota Ultrasonics DFX-6 Operating Manual

DFX-625

User’s Guide

DFX-625 User’s Guide ~ Contents

Copyright © 2008 Dakota Ultrasonics

All rights reserved. No part of this publication may be reproduced, stored in a retrieval
system or transmitted in any form or by any means, electronic, mechanical, photocopying,
recording or otherwise, without the prior written permission of Dakota Ultrasonics.

Dakota Ultrasonics

1500 Green Hills Road, #107
Scotts Valley, CA 95066 USA
Phone: [phone]
Fax: [phone]
email: [e-mail]
Web: www.dakotaultrasonics.com

DFX-625 User’s Guide ~ Contents

Contents

Contents.........................................................................................................................................i

1 How to Use This User’s Guide................................................................................................1

1.1 Typographical Conventions ...........................................................................................1

2 Disclaimers and Notices .........................................................................................................2

2.1 Specific Warnings..........................................................................................................2

2.2 General Warnings..........................................................................................................2

2.3 Operator Training ..........................................................................................................2

2.4 Testing Limitations.........................................................................................................2

2.5 Critical Operating Factors..............................................................................................2

2.5.1 Calibration of the Sound Velocity...............................................................................3

2.5.2 Transducer (Probe) Zero Procedure..........................................................................4

2.5.3 Flaw Detection Calibration.........................................................................................4

2.5.4 Effects of Temperature on Calibration.......................................................................4

2.5.5 Transducer Condition ................................................................................................4

2.5.6 Use of Couplant.........................................................................................................4

2.6 Disclaimer of Liability.....................................................................................................5

2.7 Electromagnetic Compatibility .......................................................................................5

3 Quick Start ..............................................................................................................................6

3.1 Front Panel Controls & End Cap Connections ..............................................................6

3.2 Flaw Detection...............................................................................................................9

3.3 Thickness Gauging......................................................................................................10

3.4 DFX-625 Memory ........................................................................................................11

3.4.1 Reset to factory defaults:.........................................................................................11

3.4.2 Clearing the Memory ...............................................................................................11

4 Detailed Menu Description....................................................................................................12

4.1 Menu Tree ...................................................................................................................12

4.2 Main Menu...................................................................................................................13

4.2.1 Main Menu Selection ...............................................................................................13

4.3 CAL Menu....................................................................................................................14

4.3.1 Calibration Menu .....................................................................................................14

4.3.2 Amplifier Menu.........................................................................................................14

4.3.3 GATE1 & GATE2 Menus .........................................................................................15

4.3.4 A-CAL Menu ............................................................................................................15

4.4 MEAS Menu ................................................................................................................17

4.4.1 Measurement Menu.................................................................................................17

4.4.2 CSC (Curved Surface Correction) ...........................................................................19

4.4.3 PROBE Menu ..........................................................................................................19

4.4.4 Distance Amplitude Correction (DAC) Menu ...........................................................20

4.4.5 DGS/AVG ................................................................................................................21

4.4.6 TCG Time Corrected Gain Menu.............................................................................22

4.4.7 AWS Menu ..............................................................................................................23

4.4.8 API Menu.................................................................................................................24

4.5 UTIL Menu...................................................................................................................25

4.5.1 UTIL Menu...............................................................................................................25

4.5.2 VIDEO Menu ...........................................................................................................25

4.5.3 MISC Menu..............................................................................................................25

4.5.4 AGC (Automatic Gain Control) ................................................................................26

4.5.5 PRINT Menu............................................................................................................27

4.5.6 P_O/P Proportional Output Control Menu ...............................................................27

4.5.7 CLOCK Menu ..........................................................................................................28

4.6 MEMORY Menu ..........................................................................................................29

Page i

DFX-625 User’s Guide ~ Contents

4.6.1 PANEL Memory Menu............................................................................................. 29

4.6.2 A-LOG Memory Menu ............................................................................................. 30

4.6.3 REF Menu ............................................................................................................... 31

4.6.4 T-LOG Menu Numeric Mode ................................................................................... 31

4.6.5 T-LOG Menu Sequential Mode ............................................................................... 32

4.6.6 T-FN Menu .............................................................................................................. 32

4.7 Storage & Recall of Calibration Setups....................................................................... 33

4.7.1 To store a panel set:................................................................................................ 33

4.7.2 To recall a panel set: ............................................................................................... 33

4.7.3 To delete a panel set:..............................................................................................33

4.7.4 Adding NOTES to PANEL and A-LOG sets ............................................................ 33

4.7.5 Edit Notes Summary ...............................................................................................34

4.7.5.1 Using the Front Panel Keypad......................................................................... 35

4.7.5.2 Using the Optional Keyboard........................................................................... 35

5 Flaw Testing ......................................................................................................................... 36

5.1 Basic Flaw Testing ...................................................................................................... 36

5.2 Flaw Testing Calibration.............................................................................................. 37

5.3 DAC Operation............................................................................................................ 40

5.4 TCG Operation............................................................................................................ 42

5.5 Weld Inspection Using Trigonometry Mode ................................................................44

5.6 Weld Inspection Using the AWS Menu .......................................................................46

5.7 Evaluation of Pipe Imperfections using API 5UE ........................................................48

5.8 DGS/AVG Operation ...................................................................................................50

5.8.1 Theory ..................................................................................................................... 50

5.8.2 DGS/AVG Frequency, NFL and ERS...................................................................... 51

5.8.3 DGS/AVG dVK, Delay ............................................................................................. 51

5.8.4 DGS/AVG T-Loss, Ref dB and Mat dB.................................................................... 52

5.8.5 DGS/AVG ~ TBVEL, REF TYPE and REFSIZE......................................................53

5.8.6 DGS/AVG Calibration..............................................................................................54

5.8.6.1 Adjustment....................................................................................................... 55

5.8.7 Measurement ..........................................................................................................56

5.9 A-LOG, A-Scan Storage.............................................................................................. 57

5.9.1 To Store An A-Scan: ...............................................................................................57

5.9.2 To Recall an A-Scan: ..............................................................................................58

5.9.3 To Delete a Stored A-Scan .....................................................................................58

5.9.4 REF, Reference Waveform Comparisons ............................................................... 58

5.9.5 To Recall an A-Scan as a Reference Waveform:.................................................... 58

5.9.6 Contour & Peak Echo Dynamics ............................................................................. 59

6 Thickness Gauging...............................................................................................................61

6.1 Basic Thickness Gauging............................................................................................61

6.2 A-Cal ...........................................................................................................................63

6.3 TCG for Reliable Gauging ........................................................................................... 64

6.4 T-LOG Thickness Storage (Numeric)..........................................................................65

6.5 T-LOG Thickness Storage (Sequential & Download)..................................................66

6.6 T-FN Thickness Log Editing and Printing.................................................................... 68

6.6.1 To print a single Location: ....................................................................................... 68

6.6.2 To print all Locations in a single Block: ...................................................................68

6.6.3 To print all Blocks and all Locations: ....................................................................... 68

7 Power Supply ....................................................................................................................... 69

7.1 Lithium-Ion Battery Pack .............................................................................................69

7.1.1 Battery Cautions......................................................................................................69

7.2 Battery Charging .........................................................................................................70

7.2.1 Charging Caution ....................................................................................................70

8 Interface Connections ..........................................................................................................72

8.1 RS232 .........................................................................................................................72

8.2 Composite Video......................................................................................................... 73

Page ii

DFX-625 User’s Guide ~ Contents

8.3

Proportional Outputs....................................................................................................73

8.4 Synchronisation Outputs .............................................................................................73

9 Features of the DFX-625 ......................................................................................................74

9.1 Functional Testing Methods ........................................................................................74

10 Specifications........................................................................................................................75

11 Warranty ...............................................................................................................................78

12 Index .....................................................................................................................................79

Page iii

DFX-625 User’s Guide ~ How to Use This User’s Guide

1 How to Use This User’s Guide

This user’s guide has been designed so that a person with a good knowledge of the basics of
ultrasonic non-destructive testing may understand the operation and use of the features
offered by the DFX-625. The user is advised, however, of the important nature of ultrasonic
non-destructive testing and is referred to Section 2 for important information on the proper
use of this technology.

Section 1: How to Use This User’s Guide is this section.

Section 2: Disclaimers and Notices contains important information that must be understood
by users of the DFX-625

Section 3: Quick Start provides a user familiar with ultrasonic testing a means to operate the
instrument’s basic functions and to quickly achieve familiarity without having to understand
all of its features in detail.

Section: 4: Detailed Menu Description is an in-depth description of the menu items found in
the DFX-625 with brief descriptions of each item.

Section 5: Flaw Testing gives guidelines on performing flaw testing with examples of how to
calibrate the DFX-625 and how to set up the unit for DAC, TCG, DGS/AVG and how to use
the A-Scan storage facilities.

Section 6: Thickness Gauging gives guidelines on performing thickness measurements
including the calibration of the DFX-625, using TCG and how to use the thickness
measurement memory functions.

Section 7: Power Supply describes important aspects of using and caring for the battery
power supply so as to get maximum battery duration time and life.

Section 8: Interface Connections is for users who desire to operate the DFX-625 with
ancillary equipment.

Section 9: Features of the DFX-625 is a quick reference listing the pertinent characteristics of
the instrument and the various functional testing methods that may be used with the
instrument.

The function keys are shown throughout this manual as shown in Section 3.1, Front Panel

Controls.

1.1 Typographical Conventions

When describing front panel buttons the text is printed in this font.

When describing settings in the DFX-625 the text is.

printed in this font

Page 1

DFX-625 User’s Guide ~ Disclaimers and Notices

2 Disclaimers and Notices

The following information must be read and understood by users of the Dakota Ultrasonics
DFX-625 ultrasonic flaw detector and thickness gauge. Failure to follow these instructions
can lead to serious errors in test results or damage to the flaw detector. Decisions based on
erroneous results can lead to property damage, personal injury or death. Anyone using this
instrument should be fully qualified by their organization in the theory and practice of
ultrasonic testing, or under the direct supervision of such a person.

2.1 Specific Warnings

The DFX-625 contains a high-energy, precision pulser allowing optimum testing results to be
obtained by matching the pulse width to the probe characteristics. This circuitry may be
damaged by voltage spikes. It is recommended that the instrument be switched off, or the

pulser stopped (by pressing the

key) before changing transducers (probes).

2.2 General Warnings

Proper use of the ultrasonic test equipment requires three essential elements:

• Knowledge of the specific test or inspection and applicable test equipment.

• Selection of the correct test equipment based on knowledge of the application.

• Competent training of the instrument operator.

This user’s guide provides instruction in the basic operation of the DFX-625 flaw detector. In
addition to the methods included, many other factors can affect the use of this flaw detector.
Specific information regarding these factors is beyond the scope of this manual. The user
should refer to appropriate textbooks on the subject of ultrasonic testing and thickness
gauging for more detailed information.

2.3 Operator Training

Operators must receive adequate training before using this ultrasonic flaw detector.
Operators must be trained in general ultrasonic testing procedures and in the set-up and
performance required by each specific test or inspection. Operators must understand:

• Sound wave propagation theory.

• Effects of the velocity of sound in the test material.

• Behaviour of the sound wave at the interface of two different materials.

• Sound wave spread and mode conversion.

More specific information about operator training, qualification, certification and test
specifications can be obtained from technical societies, industry groups and government
agencies.

2.4 Testing Limitations

In ultrasonic testing, information is obtained only from within the confines of the sound beam
as it propagates into the test material. Operators must exercise great caution when making
inferences about the nature of the test material outside the limits of the sound beam. The
condition of materials can vary significantly and the results can be erratic if operators don’t
exercise good judgment.

2.5 Critical Operating Factors

The following procedures must be observed by all users of this ultrasonic flaw detector in
order to obtain proper and accurate results.

Page 2

DFX-625 User’s Guide ~ Disclaimers and Notices

2.5.1 Calibration of the Sound Velocity

An ultrasonic flaw detector operates on the principle of measuring the time of flight of a burst
of high frequency sound through the test piece as well as evaluating the amplitude of
reflected or transmitted echoes. The sound velocity of the test piece multiplies this time in
order to obtain an accurate distance or thickness reading. Since the actual sound velocity in
materials can vary from the published values, the best result is obtained when the instrument
is calibrated on a reference block made from the same material as the test piece. This block
should be flat, smooth and as thick as the maximum thickness expected of the test piece.

Users should also be aware that the sound velocity might not be constant throughout the test
piece due to effects such as heat-treating. This must be taken into consideration when
evaluating the results of ultrasonic thickness testing. The calibration should always be
checked after testing to minimize errors.

Page 3

DFX-625 User’s Guide ~ Disclaimers and Notices

2.5.2 Transducer (Probe) Zero Procedure

The transducer calibration procedures must be performed as described in this manual. The
calibration block must be clean, in good condition and free of noticeable wear. Failure to
perform the transducer zero and calibration procedure will cause inaccurate thickness
readings.

2.5.3 Flaw Detection Calibration

When performing flaw detection, it is important to note that the amplitude of indications is not
only related to the size of the discontinuity; the depth of a discontinuity below the test piece
surface will also have an effect on the amplitude due to characteristics of the sound beam
spread and near field zone of the transducer. In addition, the characteristics of the
discontinuity such as orientation and classification can alter the expected amplitude
response. For these reasons, calibration should be performed on test blocks made of the
same material as the test piece with artificial discontinuities within the range of size and
depth in the material to be detected. The user is again cautioned to refer to reference books
which are beyond the scope of this manual.

2.5.4 Effects of Temperature on Calibration

The sound velocity in test pieces and the transducer wear face changes with temperature
variations. All calibrations should be performed on site with test blocks at or near the same
temperature as that expected on the test piece, to minimize errors.

2.5.5 Transducer Condition

The transducer used for testing must be in good condition, without noticeable wear of the
front surface. The specified range of the transducer must encompass the complete range of
the thickness to be tested and/or the types of discontinuities to be investigated. The
temperature of the material to be tested must be within the transducer’s specified
temperature range.

2.5.6 Use of Couplant

Operators must be familiar with the use of ultrasonic couplant. Testing skills must be
developed so that couplant is used and applied in a consistent manner to eliminate variations
in couplant thickness which can cause errors and inaccurate readings. Calibration and
actual testing should be performed under similar coupling conditions, using a minimum
amount of couplant and applying consistent pressure to the transducer.

Page 4

DFX-625 User’s Guide ~ Disclaimers and Notices

2.6 Disclaimer of Liability

All statements, technical information and recommendations contained in this manual or any
other information supplied by Dakota Ultrasonics in connection with the use, features and
qualifications of the DFX-625 are based on tests believed to be reliable, but the accuracy or
completeness thereof is not guaranteed. Before using the product you should determine its
suitability for your intended use based on your knowledge of ultrasonic testing and the
characteristics of materials. You bear all risk in connection with the use of the product.

You are reminded that all warranties as to merchantability and fitness for purpose are
excluded from the contract under which the product and this manual have been supplied to
you. The Seller’s only obligation in this respect is to replace such quantity of the product
proved to be defective.

Neither the seller nor the manufacturer shall be liable either in contract or in tort for any direct
or indirect loss or damage (whether for loss of profit or otherwise), costs, expenses or other
claims for consequential or indirect compensation whatsoever (and whether caused by the
negligence of the company, its employees or agents or otherwise).

2.7 Electromagnetic Compatibility

This product conforms to the following European Directives:

Directive 2002/95/EC on the Restriction of the Use of certain Hazardous Substances in
Electrical and Electronic Equipment (RoHS)

Directive 2002/96/EC on Waste Electrical and Electronic Equipment (WEEE)

Low Voltage Directive (LVD) 73/23/EEC

CE Marking Directive 93/68/EEC

EMC Directive 89/336/EEC. However, in order to ensure the equipment meets the
requirements, the following should be read:

Warning: This is a “CLASS A” product. In a domestic environment, this product may cause

radio interference, in which case the user may be required to take adequate
measures.

Note: This product should not be connected to cables greater than three (3) meters in

length. If this is necessary, the installation may require further EMC testing to ensure
conformity.

The DFX-625 also complies with EN 12668-1, Non-destructive testing and verification of
ultrasonic examination equipment – Part 1: Instruments. For any questions relating to the
proper use of this product, please contact the manufacturer at the number indicated on page
i

Page 5

DFX-625 User’s Guide ~ Quick Start

3 Quick Start

3.1 Front Panel Controls & End Cap Connections

The front panel controls & end cap connections consist of a series sealed, pressure
sensitive, tactile buttons that allow the instrument settings to be changed and the movement
through the menus on the screen. An optional keyboard connected to the USB port can also
be used to navigate through the menus and make changes to the parameter values. A more
detailed description of each button is shown below followed by an overview of the front
panel:

When the term “highlighted” is used, it refers to text with a bright background and dark letters
which is the selected item.

Power on & off push button for switching the instrument on and off. Operates as a
toggle.

N.B Random lines or characters may be displayed for a second or two after switch
on, before the memory is initialized, this is normal.

The Menu button is used to display the 4 main menu levels (

MEMORY) on the right hand side of the screen. The MENU button can be pressed at

any time. To select the required sub-menu press the plain function button
associated with it. Corresponds to the “ESC” key when using a keyboard.

CAL, MEAS, UTIL and

These buttons move the highlighted cursor along the top of the screen left and right
to the sub menu to be selected. These are momentary buttons with no repeat. The
parameter boxes along the right hand side of the screen change as the sub menu is
selected. Corresponds to left and right arrows (w and x) when using a keyboard.

The four function buttons on the right side of the display are used to select the menu
boxes, which appear on the right side of the A-Trace. When a menu box is selected,
it will be highlighted. Pressing the button a second time will, on certain parameters,
display a drop-down list with a selection of values that can be chosen by using the

and buttons. When using a keyboard F1 to F4 correspond to the 4 white

buttons.

This button operates in connection with the function buttons next to the parameter
boxes to increase the value or step the selection in the positive direction. In the
case of transducer

Zero or Delay, it moves the signals to the right. This is a repeat

button with acceleration to facilitate quick scrolling of the value. Corresponds to up
arrow (y) when using a keyboard.

This button operates in connection with the function buttons next to the parameter
boxes to decrease the value or step the selection in the reverse direction. In the
case of transducer

ZERO or Delay, it moves the signals to the left. This is a repeat

button with acceleration to facilitate quick scrolling of the value. Corresponds to
down arrow (z) when using a keyboard.

This button changes the size of the steps that are used to adjust the parameters;
there are two sizes: small and large that are dependant on the parameter that is
being changed. The button toggles between the two sizes and the current state is
indicated by X for small and by XX for the larger step in the parameter box that is
being adjusted. Corresponds to the letter “I” when using the keyboard.

This button operates in conjunction with the memory menus to accept a store or to
accept a recall of a memory already in storage. In the print mode,

OK acts as the

print button. Corresponds to “Enter” or the return key.

Page 6

DFX-625 User’s Guide ~ Quick Start

Press this button once to select freeze mode for the A-Scan display. This is a useful
feature for holding an echo for evaluation. When in this mode, a box is highlighted
showing

FREEZE below the graticule.

Pressing the button a second time selects peak mode, which holds and updates all
echoes on the display during inspection. This feature allows an envelope or echo
dynamic pattern to be drawn on the screen which is useful for angle beam inspection
to locate the peak signal. When in this mode, a box is highlighted showing

PEAK

below the graticule.

If key lock is enabled from within the
selects

KEYLOCK mode, preventing accidental changing of parameters

UTIL menu, pressing the button a third time

Pressing the button a fourth time returns the A-Trace display to normal mode. This
is a momentary button with no repeat action. Corresponds to the letter “F” when
using the keyboard.

This button selects the help menu which overlays the display. The help menu
explains how the DFX-615 operates with a choice of three options:

Using the DFX-615

Description of the active menu

Calibration procedure.

Pressing the

HELP button again at any point in the help screens returns the display

to normal mode. The Help Screen also displays the Instrument serial number &
software version. Corresponds to “F5” when using a keyboard.

The full screen button is used to toggle between showing the A-Scan on the full
display and showing it with the menus and parameter boxes. If split screen is
enabled from the UTIL menu this button is used to display the A-Scan in the upper
half of the display and parameters in the lower half.

Press to select the dB step value of amplifier gain as 0.1, 0.5, 1, 2, 6, 10, 14, or
20dB. The selected value is indicated at the top right-hand corner of the gain box,
which is always located at the bottom right side of the screen. This is a momentary
button with no repeat. Corresponds to the letter “X” when using a keyboard.

Press to increment or decrement the gain value indicated in the gain box. This is
always located at the bottom right side of the screen. This is a repeat button with
acceleration to facilitate quick changing of the value. Corresponds to “Page Up” and
“Page Down” when using a keyboard.

Selects either reference or gain settings within the gain box. When reference is
selected, the increment and decrement buttons will change both the reference and
gain values together. This is a momentary button with no repeat. Corresponds to
the letter “R” when using a keyboard.

This button toggles between single and double element transducers. The user
should switch the unit off or stop the pulser by pressing the

FREEZE/PEAK key

before changing transducers. Corresponds to the letter “S” when using a keyboard.

BNC or LEMO 1 connector is the transmitter and receiver socket used for single
transducers or as the transmitter only, for twin or dual transducer operation. Refer to
back label.

BNC or LEMO 1 connector is the receiver socket used for twin or dual transducer
operation. Refer to back label.

A socket to connect various USB devices such as a printer, keyboard or the user’s
PC. Refer to back label.

Page 7

DFX-625 User’s Guide ~ Quick Start

A socket used to connect the battery charger for recharging the battery pack. A red
dot is provided on both the socket and plug to facilitate alignment. Refer to back
label.

Refer to Power Supply

for information on power supplies and charging of the battery

pack.

Page 8

DFX-625 User’s Guide ~ Quick Start

3.2 Flaw Detection

Perform the following steps to establish a basic flaw detection mode for the DFX-625. Units
shown are in inches. For metric units, select
corresponding values for the parameters.

1. Select a suitable transducer, preferably a 5MHz, half inch diameter narrow band.

METRIC UNITS from the UTIL menu and use the

2. When making a quick adjustment on a menu parameter, press the

button until the

double arrow appears next to the parameter name. This establishes the fast scroll using
the

3. In the

•

•

•

•

•

4. In the

•

•

5. In the

•

•

•

•

6. In the

•

•

•

•

and buttons.

CAL menu, set the following parameters:
ZERO to 0.000
VEL should be set the specimen material velocity.
RANGE to125 or other suitable value to cover the test range of interest.
DELAY to 0.000
GAIN to 50.0

AMP menu, set the following parameters:
DETECT to FULL
PRF to 150Hz

GATE1 menu, set the following parameters:
STATE to ON +VE
START to 10.0
WIDTH to 50 or other suitable value to cover the test range of interest.
LEVEL to 50.0

MEAS menu, set the following parameters:
MODE to DEPTH
TRIGGER to FLANK
HUD to OFF
T-MIN to OFF

The DFX-625 is now configured for basic flaw detection. Using an appropriate calibration
block, adjust the

GAIN parameter to establish the correct sensitivity. Adjust other parameters

as necessary to optimize the calibration. For more in-depth features of the DFX-625, see

Flaw Testing on page 36.

Page 9

DFX-625 User’s Guide ~ Quick Start

3.3 Thickness Gauging

Perform the following steps to establish a basic thickness-gauging mode for the DFX-625.
Units shown are in metric. For inch units, select
corresponding values for the parameters.

1. Select a suitable transducer, preferably a broadband, 5MHz, with a 10mm diameter.

2. Select an appropriate calibration block with at least three known thickness sections
covering the range to be inspected and made from the same material as the test piece.

INCHES from the UTIL menu and use the

3. When making a quick adjustment on a menu parameter, press the

button until the

double arrow appears next to the parameter name. This establishes the fast scroll using
the

4. In the

•

•

•

•

•

5. In the

•

•

6. In the

•

•

•

•

7. In the

•

•

•

•

and buttons.

CAL menu, set the following parameters:
ZERO can be left alone
VEL should be set to the specimen material velocity.
RANGE to 5” or other suitable value to cover the test range of interest.
DELAY to 0.000
GAIN to 50.0

AMP menu, set the following parameters:
DETECT to +VE HW
PRF to 150Hz

GATE1 menu, set the following parameters:
STATE to +VE
START to 10
WIDTH to 50 or other suitable value to cover the test range of interest.
LEVEL to 25.0

MEAS menu, set the following parameters:
MODE to DEPTH
TRIGGER to FLANK
HUD to ON
T-MIN to OFF

8. Calibrate the thickness readout on the selected calibration block using the procedure in

A-Cal on page 63.

The DFX-625 is now configured for basic thickness gauging. Adjust parameters as
necessary to optimize the calibration. For more in-depth features of the DFX-625, see

Thickness Gauging on page 61.

Page 10

DFX-625 User’s Guide ~ Quick Start

3.4 DFX-625 Memory

The settings of the DFX-625 always remain in memory when the instrument is turned off,
even if the battery pack is removed. That is, whatever the settings are just prior to turning
the instrument off will be the settings in place the next time the instrument is turned on.

At times it may be desirable to start with default settings. This is especially true when
beginning a new test procedure or going from flaw detection to a thickness gauging
procedure. Otherwise, it may be necessary to go through all of the menus to reset various
functions. A reset function is provided to facilitate the returning of all panel calibration
settings to the factory defaults.

3.4.1 Reset to factory defaults:

1. Switch the instrument off.

2. Depress the

FULL SCREEN button and hold while switching the instrument on until the

reset display is seen.

3. Press the

button to reset the instrument to factory defaults

NOTE: Before performing this procedure, be sure to save any favourite settings to memory
by using the procedure outlined in Storage & Recall of Calibration Setups on page 33.

NOTE: When resetting to factory default settings the following dialogue is displayed allowing
the user to choose imperial or metric defaults:

NOTE: The video always defaults to PAL.

3.4.2 Clearing the Memory

The DFX-625’s memory can store A-Scans, thicknesses and calibration set-ups. Erasing
these values accidentally could have serious consequences and should only be done after
suitable consideration. To erase the memory follow this sequence:

1. Switch the instrument off.

2. Depress the
display is seen.

MENU button and hold while switching the instrument on until the reset

3. Press the

button to clear the DFX-625’s memory

Page 11

DFX-625 User’s Guide ~ Detailed Menu Description

4 Detailed Menu Description

Before proceeding with this section, the user should be familiar with the front panel controls
described in section 3.1 Front Panel Controls on page 6. It is also assumed that the user
has a good understanding of the theory and practice of ultrasonic testing.

4.1 Menu Tree

This diagram represents the menu structure of the DFX-625; there are 4 main menu items
with sub-menus below. The sub-menus are described in the following section.

When The DFX-625 is switched on, an information screen is displayed momentarily showing
the instrument serial number and software version number while a self-test is performed as
shown below:

Page 12

DFX-625 User’s Guide ~Detailed Menu Description

4.2 Main Menu

After the information screen disappears the main menu selections are shown on the right
hand side of the screen. To select a particular menu press the function button to the right of
it. You can return to the main menu selection at any time by pressing the

4.2.1 Main Menu Selection

MENU button.

CAL

MEAS

UTIL

MEMORY

Note: The

Used to select the Calibration menu items: CAL,

AMP, GATE1, GATE2 and A_CAL

Used to select the Measurement menu items:

MEAS, CSC, PROBE, DAC, AVG, TCG, AWS and
API

Used to select the Utilities menu items: UTIL,

VIDEO, MISC, AGC, PRINT, P_O/P and CLOCK

Used to select the Memory menu items: PANEL,

A-LOG, REF, T-LOG and T-FN

REF/GAIN box always appears at the bottom right of the screen and can be

changed using the

Throughout the
menus there
are parameter
boxes that
have a thick
line
underneath
them as shown
here:

STEP, REF/GAIN and the and keys.

Pressing the grey
button next to one
of these parameter
boxes produces a
drop-down list as
shown here:

Press the grey
button again to
remove the drop­down list after the
required value has
been selected.

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DFX-625 User’s Guide ~ Detailed Menu Description

4.3 CAL Menu

The CAL menu is the most used menu and contains those items that allow the DFX-625 to
be easily calibrated. For full instruction on how to perform a calibration see Flaw Testing

Calibration on page 37

4.3.1 Calibration Menu

ZERO

Used to calibrate the screen and thickness readout
for zero offsets that are inherently different for
each transducer. Units are microseconds in both
mm and inch modes.

VEL

Used to calibrate the screen and thickness span
readout based on the velocity of sound in the test
material. Units are meters per second in mm
mode and inches per microsecond in inch mode.

RANGE

Used to set the full screen width of the horizontal
A-Trace in mm, inches, or microseconds
depending on the Units chosen in the
The range is 1mm to 20 meters (0.05 to 800
inches).

DELAY

Used to set the delay or offset of the left side of the
A-Trace for viewing of a portion of a signal. The
range is 0 to 20 meters (0 to 800 inches).

4.3.2 Amplifier Menu

FREQ

Used to set the centre frequency band of the
amplifier to match the transducer. Ranges are 1,

2.5, 5 & 10MHz narrow bands and 1.5 – 15MHz
wide band.

UTIL menu.

DETECT

REJECT

PRF MAX

Used to set the display mode for the desired
rectification of the signals from
full wave),
half-wave) and

RF ( un-rectified), -VE HW (negative

+VE HW (positive half-wave)

FULL (rectified

Used to remove low level noise from the A­Trace. Reject is linear and is adjustable from 0
up to 50% of full screen height. The

REJECT

LED is lit when a reject is active.

Used to set the maximum pulse repetition
frequency. Selectable values are from 35 to 100
in 5Hz steps, from 100 to 1,000 in 50Hz steps.
Lower values will reduce ghosting and noise
echoes.

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DFX-625 User’s Guide ~Detailed Menu Description

4.3.3 GATE1 & GATE2 Menus

There are two gates available in the DFX-625 with slightly different options depending on the
gate and the measurement mode chosen. The following describes the available settings for
each gate with the differences between the gates stated. The gates can be identified by the
fact that gate 1 has the number “1” above the line and gate 2 has the number “2” above it.

STATE

START

Set the state of the gate as follows:

+VE: The alarm triggers when an echo in

the gate exceeds the threshold level.

-VE: The alarm triggers when an echo in

the gate falls below the threshold
level. Usually used to monitor for loss
of back wall echo.

EXPAND: Expands the gate width to fill the

horizontal display width. Only applies
to gate 1.

OFF: Switches the gate off.

-VE DLY: (Gate 2 only) This fourth state on gate

two implements a gate to alarm delay
of 600 milliseconds. This requires that
the signal be lost from the gate for a
continuous period of 600 milliseconds
before the alarm is activated. This is
implemented for the alarm LED,
buzzer and external alarm output via
the proportional output connector.

Used to set the start position of the gate relative
to the initial pulse.

Units are mm or inches and range is from 0 to
the full time base of the horizontal display.

WIDTH

Used to set the width of the gate. Units are mm
or inches and range is from 0.15mm (0.001 inch),
depending on the range selected, to the full time
base of the horizontal display.

LEVEL

Used to adjust the alarm threshold level, which
corresponds to the vertical height on the A-Trace.
Adjustable in 0.5% or 2% steps from 0% to 100%
full screen height.

4.3.4 A-CAL Menu

This menu provides automatic calibration of sound velocity and
transducer zero. Gate 1 is used to select the reference echoes. See

A-Cal on page 63 for a full procedure.

DIST1

DIST2

ACCEPT

The actual distance to the first or thinnest
reference echo in the calibration block.

The actual distance to the second or thickest
reference echo in the calibration block

After pressing OK to accept DIST1 and DIST2.
Press

OK when ACCEPT CAL is highlighted.

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DFX-625 User’s Guide ~ Detailed Menu Description

START

Used to adjust the start of the gate to assure that
the first and second echoes are measured

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DFX-625 User’s Guide ~Detailed Menu Description

4.4 MEAS Menu

The menus in this section allow the various measurement techniques to be configured; these
include the general measurement set-up and specialist methods such as DAC, AVG, TCG,
AWS and API. Select the

4.4.1 Measurement Menu

In the measurement menu, the top selection box shows the selected
measurement mode and the remaining three selection boxes vary
depending on the mode selected as follows:

MEAS menu at any time by pressing the MENU button.

MODE:
MONITOR

MODE:
DEPTH

TRIGGER

HUD

In this mode, gates 1 and 2 act as two
independent monitor gates

In this mode, gate 1 functions as a depth or
thickness monitor and displays the depth (D:)
and height (H:) of the first signal after the start of
the gate that reaches or exceeds the gate level
threshold. Values are displayed in a highlighted
box below the A-Trace.

Used to select the depth or thickness
measurement to the
echo after the start of the gate or the

FLANK (left edge) of the first

PEAK

measurement within the gate i.e. the largest
value in the gate.

When turned

ON, provides a large, Head-Up

Display of the depth or thickness reading at the
top right of the A-Trace. The

button

sequences the selections as follows:
G1-G2 E-E DEPTH TRIG

OFF OFF OFF OFF
DIST DIST DIST DIST
DIST + DIST + HEIGHT HEIGHT
DIST + DIST +
HEIGHT + HEIGHT +

¾ +

 +

¾

Â

T-MIN

When turned ON, the depth or thickness reading
will freeze that last minimum or lowest value
measured. To reset, toggle the function to OFF
and then ON. Only available in the DEPTH
mode.

MODE:
E-E

In this mode, gate 1 functions as a thickness
monitor and measures the thickness between the
first signal in the gate and the second signal in
the gate that reaches or exceeds the level
threshold. A second bar is shown representing
the blanking (see BLANK)

BLANK

This function sets the blanking distance, as a
percentage of the total gate width, which is a

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DFX-625 User’s Guide ~ Detailed Menu Description

blind zone after the first echo, after which a
second echo can be measured. This helps to
eliminate undesired noise in the first echo from
being measured, as thickness but will limit the
minimum thickness capability if set too large

MODE:
G-G

MODE:
TRIG

THICK

This is similar in concept to E-E mode, but uses
gates 1 & 2, allowing the thresholds for the two
gate measurements to be completely
independent.

The Trigonometry mode is used with angle beam
transducers for weld inspection to calculate the
three important measurements based on the
echo position: the Beam path distance (Â:), the
Surface distance (¼:), and the Depth distance
(¾:) from the index point of the transducer.

Set to the thickness of the material being tested
to account for multiple skips of the angled sound
beam in the test material.

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DFX-625 User’s Guide ~Detailed Menu Description

4.4.2 CSC (Curved Surface Correction)

This menu allows the user to configure the Curved Surface Correction
(CSC) parameters. This feature normally used when testing pipes and
other curved surfaces. In order for the correction to be made the correct
wall thickness must be selected in the
selected in the

MEAS menu.

THICK option when TRIG is

MODE
Surface

Turn CSC ON or OFF.

Choose CONCAVE for internal surfaces or
CONVEX for external surfaces

RAD

Select the radius of the curvature.

4.4.3 PROBE Menu

ANGLE

X-OFFSET

1/2 SKIP

Set to the nominal refracted angle of the
transducer to calibrate the Surface and Depth
measurements

Used to enter the distance from probe emission
point to front of probe case. This is used by the
TRIG function in MEAS menu to give the
surface distance.

Used as a quick way to turn on the ½ skip
graticule.

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DFX-625 User’s Guide ~ Detailed Menu Description

4.4.4 Distance Amplitude Correction (DAC) Menu

This menu is used to create DAC curves using a series of reference
echoes. Once drawn, the DAC curve acts as an alarm threshold level
for the gate where the level varies to match the attenuation and field
characteristics of the transducer and test material combination. The
DAC procedure is described fully in DAC Operation on page 40.

MODE:
ON

CURVE

TRIGGER

MEAS

MODE:
DRAW

CURSOR

POINT

Displays the DAC curve on the screen

Used to display the DAC curve alone, the -6/­12dB, -6/-14dB, -2/-6/-10dB, -2dB, -6dB or -10dB
reference curves.

Used to set the alarm threshold for the DAC
curve, -2dB, -6dB, -10dB, -12dB or -14dB curve
or the gate.

Used to select the measurement value in dB, %
Full Screen Height (FSH) or %DAC for any signal
that is in the curve or gate.

Used to create the DAC curve.

Used to move the cursor over the reference echo
for which a DAC point is being set.

Display only. Shows the number of points
created after pressing the

OK button.

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DFX-625 User’s Guide ~Detailed Menu Description

4.4.5 DGS/AVG

This menu is used to create a DGS/AVG curve that allows flaw sizing
and distance compensation without requiring the reference standards
that would be required for establishing a DAC curve or to set up a TCG
correction. The DGS/AVG procedure is described fully in DGS/AVG
Operation on page 50.

MODE:
OFF

FREQ

NFL

ERS
MODE:

SET PRB
dVK

DELAY

MODE:
SET ATT

T-LOSS

Initial mode. Turns off the display of the
DGS/AVG curve

Used to set the transducer frequency taken from
its datasheet.

Used to set the Near Field Length taken from the
transducer datasheet

Used to set the Equivalent Reflector Size.

Mode used to define curvature correction and
probe delay

Used to set the curvature correction factor in dB
and is taken from the transducer datasheet.

Used to set the probe delay material velocity in
m/s and is used in conjunction with the probe
zero and specimen velocity to calculate the
sound field equivalent length.

Used to set attenuation parameters

Used to set the transfer loss in dB due to surface
condition, poor coupling etc…

REF dB/m

MAT
dB/m

MODE:
SET REF

TBVEL

REF TYPE

REFSIZ

MODE:
SET SIG

CURSOR

Used to set the reference material attenuation in
dB/m

Used to set the test material attenuation in dB/m

Used to define the various reference values

Used to set the reference (test) block velocity in
m/s

Used to select the reference reflector type: Flat
Bottom Hole (
Back Wall Echo (

FBH), Side Drilled Hole (SDH) or

BWE)

Used to define the size of the reference type. If

REF TYPE is set to BWE, REFSIZE is set to
INFINITE

Mode used to perform calibration

Select than use the and keys to move the
selection over the echo and press

OK. The DFX-

625 will calculate the sensitivity and draw the
curve on the screen

MODE:

Mode in which DGS/AVG is on.

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DFX-625 User’s Guide ~ Detailed Menu Description

ON
TRIGGER

Used to select either the GATE or the CURVE as
the measurement reference

ERS

Used to set the Equivalent Reflector Size.

4.4.6 TCG Time Corrected Gain Menu

This menu is used to create TCG curves using a series of reference
echoes. Once drawn, the TCG curve acts as swept gain control on the
amplifier to set different gain levels relative to distance. The TCG
procedure is described fully in TCG Operation on page 42

MODE:
ON

CURVE
MODE:

DRAW
CURSOR

POINT

Activates the TCG curve to adjust the gain. Can
be activated in RF or rectified display modes.

When switched ON, the TCG curve is displayed.

Used to create the TCG curve. Cannot be drawn
in RF display mode.

Used to move the cursor over the reference echo
for which a TCG point is being set

Display only. Shows the last point created after
pressing the

OK button.

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DFX-625 User’s Guide ~Detailed Menu Description

4.4.7 AWS Menu

This menu is used when performing weld inspection in accordance with
the American Welding Society’s Structural Welding Code, ANSI/AWS
D1.1-94. It provides a convenient method to automatically calculate the
Indication Rating as defined in the code. The AWS procedure is
described fully in Weld Inspection Using the AWS Menu on page 46

MODE:
SET

REF
CURSOR

MODE:
MEAS

IL dB

AF dB

IR dB

Used to set up the AWS measurement mode.

Used to set the Indication Level.

Used to move the cursor over the reference echo
to set the reference level.

Used to make measurements in accordance with
the code.

The dB required setting the indication to the
reference level.

The attenuation factor to correct for the depth of
the indication.

The indication rating calculated in accordance
with the code. Also the difference the IL and the
reference level with correction for attenuation.

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DFX-625 User’s Guide ~ Detailed Menu Description

4.4.8 API Menu

This menu is used to assist users in performing tests according to the
American Petroleum Institute (API) Recommended Practice for
Ultrasonic Evaluation of Pipe Imperfections using the Amplitude
Distance Differential Method (ADDM). Users are referred to the
publication: “API Recommended Practice 5UE, Second Edition, June
2005” The API procedure is described in Evaluation of Pipe

Imperfections using API 5UE on page 48

MODE:
CAL

dr

START

MODE:
MEAS

START

k

di

Used to set the initial calibration of the defect.

Depth of the reference indicator; should be set by
the user according to the size of the reference
defect.

The position of the gate that is used to set the
calibration

Used once the calibration has been done to
make comparative measurements.

Used to position the start of the gate used for
making measurements

The k factor, derived during the calibration phase
and used to calculate the depth of the defect. It
can’t be changed during the measurement phase
and id displayed for reference.

Imperfection depth calculated by the DFX-625

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DFX-625 User’s Guide ~Detailed Menu Description

4.5 UTIL Menu

Press the MENU button followed by the function key next to UTIL to select these menu
options. The items in this section allow the user to configure features such as units, display
preferences, language, print options, proportional output configuration and date and time
settings.

4.5.1 UTIL Menu

UNITS

Selects INCHES, µs, or METRIC measurement
units.

When in

µs mode, the velocity is fixed at 2000

m/s (5000in/µs) and is not adjustable

CLICK

When on, a beep will sound to confirm each
button press.

ALARM

When set to AUDIBLE, a buzzer will sound
during any gate alarm

SMOOTH

When SMOOTH is selected the signal is
displayed as an envelope. When
selected the area under the trace is filled.

4.5.2 VIDEO Menu

COLOR

BRIGHT

Selects one of eight color schemes for the
display

Controls the display brightness. The level
selected will affect the battery duration. A
value of 1 gives about 16 hours, the default of
10 gives about 12½ hours whereas a value
of 20 will give about 9 hours of operation,
assuming the battery is in good condition and
at room temperature.

FILL is

VIDEO

Select NTSC (USA) or PAL (UK/Europe)
composite video output modes. The screen
update rate is 50Hz in PAL and 60Hz in
NTSC. NTSC mode will be slightly brighter.

GRATICULE

Selects graticule options from the following
choices:

OFF: No graticule.
ON : A complete 100% graticule
SPARSE : A row of dots at 10% intervals.
50%: Divisions at 50% full screen height.
1/2 SKIP: Sparse with vertical dotted lines

representing the ½ skip, full skip
and 1½ skip distances.

4.5.3 MISC Menu

LANG

SPLIT

Selects one of 6 built in languages or a user
selectable language. The built in languages are
selectable at time of ordering the DFX-625.

Allows the user to display a vertically

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DFX-625 User’s Guide ~ Detailed Menu Description

compressed A-Scan in the upper half of the
screen and a sub-set of the menus in the lower
half. When set to ACTIVE the FULL SCREEN
button switches between normal, full and split
screen views.

BAUD

Allows the user to select a Baud rate for the
serial port to operate at. The choices are: 9,600
(

9K6), 19,200 (19K2), 38,400 (38K4), 57,600

(

57K6) or 115,200 (115K2).

KEYLOCK

Allows the user to “lock out” the keys of the unit
to stop inadvertent changes. When set to

ACTIVE the

button toggles between freeze,

peak and keylock.

4.5.4 AGC (Automatic Gain Control)

Automatic Gain Control feature is generally used in thickness logging.

By setting a percentage of full screen height (
signal is breaking gate 1, the gain will be adjusted automatically to bring the signal height to
the user defined value subject to an adjustable tolerance (

AGC
MODE

% FSH

Turn AGC ON of OFF

Choose the screen height to which the user
wants the gain to be adjusted.

+-% TOL

Choose the tolerance on the % FSH to stop the
AGC “hunting” due to signal height jitter. The
range can be set between 5% and 20% FSH

% FSH – default 50%) and ensuring that the

+–% TOL).

To Use:

• Set Gate 1 +ve, to a height of, say 10% or 20% FSH.

• Ensure that Measurements are enabled

• In the AGC menu: Set the %FSH parameter to the signal height required.

• Enable AGC by changing AGC Mode to ON.

• For poor surface conditions, adjust the +-% BAND to increase the tolerance of

variation in the signal before the GAIN is adjusted

• When a signal is present in Gate 1, and Measurements are ON the Gain will be
automatically adjusted to bring the signal back to the specified height on the screen.

NOTES:

• AGC defaults to OFF.

• %FSH setting is retained.

• The parameters are reset to default values on power up.

• The PRF is reduced to 250Hz to maintain consistency of internal processing.

• If the Gate level is above the user defined %FSH, AGC is internally inhibited.

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DFX-625 User’s Guide ~Detailed Menu Description

• AGC is not compatible with AVG or AWS. If either AVG or AWS is selected they will
turn AGC off.

4.5.5 PRINT Menu

This menu allows printing of information to a suitable USB printer
connected to the USB port on the DFX-625. Please note that this
requires a printer with a USB port from the Dakota Ultrasonics certified
list of printers.

OFF
DISPLAY

The print mode is switched OFF
With the print mode in Display, the screen display

will be sent to the printer when the

OK button is

pressed.

LIST CPY

With the print mode in LIST CPY, all the
calibration settings, the screen and all notes in
the edit feature will be sent to the printer when
the

OK button is pressed.

A_LOG

In the A-Log print mode, all of the stored A-Scans
that are valid will be printed when the

OK button

is pressed, along with the calibration settings and
notes. This can take considerable time if all 800
A-Scans are stored.

4.5.6 P_O/P Proportional Output Control Menu

This menu controls the analogue and digital proportional outputs. Two
outputs are provided one for depth and one for amplitude. The outputs
are active when the associated gate is triggered and are updated at the
PRF.

O/P 1

O/P 2

CAL

DEPTH1
DEPTH2: (Gate2)
E1-E2: Distance between the two depth

ALARM 1: Voltage output when alarm 1 is active
LEVEL1
LEVEL2: (Gate2)
L1-L2: The difference between the two

ALARM 2: Voltage output when alarm 2 is active

Allows the user to change the voltage on the
proportional outputs between 0V and 10.1V

: (Gate1)

measurements

: (Gate1)

amplitudes

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DFX-625 User’s Guide ~ Detailed Menu Description

4.5.7 CLOCK Menu

SET OFF

SET TIME

HOURS
MINS
SET

DATE

DATE
MONTH
YEAR

Do not display the time at the bottom of the
display

Used to set the current time.
NOTE: Be sure to press

OK to save the new

time and again to save the date.

Used to set the current hour in 24 hour format

Used to set the current minutes.

Used to set the current date.(Selected by
pressing the function button next to

SET , then

)

Used to set the current day.

Used to set the current month.

Used to set the current year.

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DFX-625 User’s Guide ~Detailed Menu Description

4.6 MEMORY Menu

Press the MENU button then the function button next to the MEMORY option to access the
Memory menu. These menus allow the user to save panel settings, A-Scans and
thicknesses as well as recalling an A-Scan to be used as a reference.

4.6.1 PANEL Memory Menu

This menu provides storage and recall of up to 100 calibration settings.
The use of this feature is described fully in Storage & Recall of

Calibration Setups on page 33

STORE
MODE:

RECALL
MODE:

DELETE

MODE:
LIST

MODE:
STORE

MODE:
INDEX

STATE

Used to select a storage location (1-100).

Used to recall a stored calibration set to the
active memory. Press

OK to recall

Used to delete a VALID (used) calibration set.
Press

OK to delete. Press OK again after the

confirmation prompt

Shows the notes associated with the stored
calibration set. Pressing

OK will recall the

calibration set at which time the Notes can be
edited.

Stores the current calibration settings in memory
to the selected Store set. Press
Press

OK again after the confirmation prompt.

OK to store.

Lists all memories, use & to change
‘page’. Cancelled by scrolling past the end

Display only. VALID indicates that the store
location is used.
used. To change

DELETE function.

EMPTY indicates that it is not

VALID to EMPTY, use the

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DFX-625 User’s Guide ~ Detailed Menu Description

4.6.2 A-LOG Memory Menu

This menu provides storage and recall of up to 800 A-Scans with
settings. The use of this feature is described fully in A-LOG, A-Scan

Storage on page 57

STORE

MODE:
RECALL

MODE:
DELETE

MODE:
LIST

MODE:
INDEX

MODE:
STORE

STATE

Used to select a storage location(1-800)

Used to recall a stored A-Scan and settings to
the active memory. Press

OK to recall. The A-

Scan is displayed in FREEZE mode. Press
to remove.

Used to delete a VALID (used) A-scan and its
settings. Press

OK to delete. Press OK again

after the confirmation prompt.

Shows the notes associated with the stored A­Scan and its settings. Pressing

OK will recall the

calibration set at which time the Notes can be
edited.

Lists all memories, use & to change
‘page’. Cancelled by scrolling past the end.

Stores the current A-Scan and its settings in
memory to the selected Store set. Press
store. Press

OK again after the confirmation

OK to

prompt.

Display only. VALID indicates that the store
location is used. EMPTY indicates that it is not
used. To change VALID to EMPTY, use the
DELETE function.

EDIT

(See Adding NOTES to PANEL and A-LOG sets
on page 33.)

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DFX-625 User’s Guide ~Detailed Menu Description

4.6.3 REF Menu

This menu allows a waveform stored in A-LOG memory to be displayed
as a reference on the display. Before a waveform can be recalled, it
must be stored in an A-LOG location as described above.

STORE

Used to select an A-LOG storage location (1-

800)

MODE:
RECALL

MODE:
LIST

MODE:
OFF

STATE

Used to recall the stored A-Scan and display it.
Press

OK to recall.

Shows the notes associated with the: stored A­Scan. Pressing

OK will recall the waveform.

Used to remove a Reference: waveform. Set
MODE to OFF, and press OK.

Display only. VALID indicates that the store
location is used. EMPTY indicates that it is not
used.

4.6.4 T-LOG Menu Numeric Mode

This menu provides storage and recall of up to 8,000 thickness readings. Numeric and
Sequential modes are available as selected in the T-FN menu. This feature is described fully
in T-LOG Thickness Storage on page 65

Readings are stored under a three level code, starting with BLOCK (1-14), followed by
Location (1-8000) and NO (1-8000).

BLOCK

Used to select the block number (1-14) for
storage or viewing of a thickness reading.

LOC

NO

THICK

Used to select the location number for storage or
viewing of a thickness reading.

The individual thickness reading number into
which a thickness reading is stored. Increments
automatically when storing a reading by pressing
the

OK button.

The thickness reading stored in the BLOCK­LOC-NO. If blank, there is no stored thickness in
that particular three level code.

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DFX-625 User’s Guide ~ Detailed Menu Description

4.6.5 T-LOG Menu Sequential Mode

Readings are stored by location (1-8000) number only. In this mode location and historical
thickness data can be downloaded to the DFX-625 from a computer, a fixed series of four
notes can be added to a location, and any of the 100 PANEL store settings can be assigned
to a location. This feature is described fully in T-LOG Thickness Storage (Sequential &

Download) on page 66.

Note: The HUD is on automatically in sequential mode.

LOC

Used to select the location number for storage or
viewing of a thickness reading.

THICK

The thickness reading stored in the LOC. If
blank, there is no stored thickness in that
number.

NOTES

One of four notes can be selected or blank.

OBSTRC for obstruction, PITTING, POOR S/C for

poor signal or couplant, and
wall echo.

AUTO
SET

Allows selection of the auto calibration feature if
the downloaded sequence contains PANEL store
numbers. The DFX-625 can then be
automatically calibrated to one of 100 panel
settings for selected sequence numbers.

4.6.6 T-FN Menu

MODE:
PRINT

MODE:
DELETE

Set the mode to PRINT to print the selected
blocks and locations to the printer on the RS232
port.

Set the mode to DELETE to delete the selected
blocks and locations. Press
confirmation prompt.

NO BWE for no back

OK again after the

BLOCK

LOC

MODE: ID

Used to select the block number for printing or
deletion. Decrement below 1 to select ALL
blocks for printing or deletion.

Used to select the location number for printing or
deletion. Decrement below 1 to select ALL
locations for printing or deletion.

Select NUMERIC or SEQUENCE Mode for Data
logging

Page 32

DFX-625 User’s Guide ~Detailed Menu Description

4.7 Storage & Recall of Calibration Setups

After the DFX-625 has been properly calibrated for a particular testing scheme, it is possible
to store all of the panel settings for subsequent recall when performing the same test at a
later time. Although the last panel settings are “remembered” by the DFX-625’s memory, this
feature is useful when the instrument is being used for many different tests requiring
substantially different panel calibration settings. In addition to the panel settings, a freeform
note can be stored with the panel set that includes provision for a label, an operator name or
number, a location identifier, and a transducer identifier. It is possible to store up to 100 sets
of panel settings; each assigned a set number from 1 to 100. A set of panel settings can be
printed after the set is recalled to active memory by using the LIST CPY function in the
PRINT menu.

4.7.1 To store a panel set:

• Press the MENU button followed by the function button next to the MEMORY option to
access the Memory menu.

• Use the

• If it is desired to store Notes with the panel settings, see the description for entering

notes below.

• Select the STORE box and, using the
number from 1 to 100. Note that as the STORE number is changed, the STATE
parameter indicates if the number is used (VALID) or EMPTY.

• Select the MODE box and using the

• Press the OK button to store the panel settings.

• If you forgot to enter Notes, create the Notes as described below and the re-save the

panel settings starting at step 5 above.

and buttons to highlight the PANEL menu.

and buttons, select a desired STORE

and buttons, select the STORE mode.

4.7.2 To recall a panel set:

Follow the above procedure but set the MODE parameter to RECALL and then press the OK
button.

4.7.3 To delete a panel set:

Follow the above procedure but set the MODE parameter to DELETE and press the OK
button.

4.7.4 Adding NOTES to PANEL and A-LOG sets

When storing panel calibration settings or waveforms, it is often useful to add some notes to
the set so it can later be identified, or to help the user recall the correct set. This is possible
in the

PANEL and A-LOG menus by using the EDIT NOTES feature.

When a panel calibration or waveform is to be stored, first calibrate the instrument as

desired, or capture the waveform by pressing the
box in the menu and notice that the window shown below overlays the display area.

Page 33

button. Then select the EDIT NOTES

DFX-625 User’s Guide ~ Detailed Menu Description

LABEL line is 8 characters long, and is used by the WinDFX PC program to allow quick

The
identification. The
the three

NOTES lines allow up to 75 characters.

OPERATOR, LOCATION and PROBE lines are 25 characters each, while

The
function button adjacent to the
next line. When the cursor is at the bottom line, the

and buttons are used to move the cursor from right to left along a line of text. The

NEXT LINE box is used to advance the cursor down to the

NEXT LINE function moves it back to the

top line.

To delete a character, position the cursor over it and press the function button adjacent to the

DELETE CHAR box.

To insert a character space, position the cursor to the right of the desired insert location and
press the function button adjacent to the

To select a character from the character map below the Notes lines, use the
buttons to move the highlight through the map. The press the
to the

NOTES at the position of the cursor.

INSERT CHAR box.

and

OK button to add the character

Once the desired notes have been added or edited, press the function button adjacent to the

EXIT box. The text is now entered but not stored. It is now necessary to store the notes

using the methods outlined in the

PANEL and A-LOG sections.

If a stored panel or A-LOG is recalled, its notes will be loaded into the window. The notes
can then be viewed and edited using the same procedure detailed above.

NOTE: When notes are displayed, the menu cursor buttons are disabled. Exit the Notes
window to change to another menu.

The following shows a completed notes window:

4.7.5 Edit Notes Summary

The following sections provide a summary of the navigation techniques needed to edit notes
using either the front panel keypad or the optional USB keyboard:

Page 34

4.7.5.1 Using the Front Panel Keypad

DFX-625 User’s Guide ~Detailed Menu Description

EDIT NOTES:

Press to bring up the editing boxes as follows: Use

and buttons to move the cursor

the
horizontally along a text line. Use the

buttons to highlight a character from the map.

NEXT LINE
INSERT CHAR

Press

Press to scroll through and select a line for editing.

Inserts a blank character space before the one the

OK to write a character to a line.

cursor is currently on.

DELETE CHAR
EXIT

Deletes the character under the cursor.

Exits back to the PANEL or A-LOG menu. Store the
calibration set to save the notes.

4.7.5.2 Using the Optional Keyboard

Keyboard
Function

Connect the optional keyboard to the USB socket
on the front panel of the set. Press
from the keypad to enter the keyboard function.

Small
Character &

Press any key on the keyboard to edit the
characters, the same applies to numbers.

Numbers

Capital

Press SHIFT + the wanted character or sign.
Character &
Signs

and

EDIT NOTES

Insert a Space Press the space bar to insert a blank character at

the position the cursor is currently on.

Delete
Character

Delete
Character

Press the backspace to delete the previous

character to the position the cursor is currently on.

Press Delete to delete the character under the

cursor
Up Arrow Press y to move the cursor up.
Down Arrow Press z to move the cursor down.

Left Arrow Press w to move the cursor left
Right Arrow Press x to move the cursor right

EXIT Press the Esc to exit back to the PANEL or A-

LOG menu. Store the calibration set to save the

notes.

Page 35

DFX-625 User’s Guide ~ Flaw Testing

5 Flaw Testing

5.1 Basic Flaw Testing

Reliable flaw detection requires three important considerations:

• Proper transducer selection

• An accurate reference block of the same material as that being tested with reference

holes representing the orientation and sensitivity desired

• Proper calibration of the instrument.

Transducers used for flaw detection are usually of the narrow band variety to provide the
best possible sensitivity to the anticipated discontinuities. In some cases, broadband
varieties are chosen to optimize near or far surface resolution – the ability to separate
discontinuities from the front surface or back surface echo. In either case, the frequency is
chosen so that the wavelength in the material is optimized for the orientation and size of
expected discontinuities. The single element contact transducer is used for general-purpose
flaw detection. The angle beam transducer is used for weld inspection, which is covered in

Weld Inspection Using Trigonometry Mode on page 44. Other specialty transducers

including dual and surface wave can be used but these topics are beyond the scope of the
manual.

The next requirement for reliable flaw detection is a calibration or reference block. This block
should be made of the same material as the parts to be inspected. In other words, it should
have the same sound velocity and attenuation characteristics. The calibration block should
have surfaces that mimic the parts to be inspected so that attenuation and sensitivity
characteristic is similar. Most importantly, the calibration block should have a series of
fabricated discontinuities representing those expected to found in the test piece. That is, the
size and orientation of the fabricated discontinuities should match the expected natural
discontinuities in the test piece. In some cases this may mean flat bottom holes
perpendicular to the test surface, side drilled holes parallel to the testing surface, or in some
cases, narrow notches representing planar surfaces parallel or perpendicular to the testing
surface. Fabricated discontinuities must also be placed near the front and back surface of
the calibration block to verify resolution of the transducer and instrument setting combination.

Finally, it is necessary to establish the proper calibration of the DFX-625 in order to assure
reliable flaw detection.

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DFX-625 User’s Guide ~Flaw Testing

5.2 Flaw Testing Calibration

The essence of this calibration is to set the pulser, amplifier and gate parameters to provide
the necessary sensitivity and resolution. The DFX-625 has an automatic calibration
technique that sets the necessary parameters by using a calibration block that has known
thicknesses; see A-Cal on page 63 for details.

Alternatively a manual method can be used to perform the calibration and the following are
the essential steps for basic flaw detection:

1. Select the appropriate single element contact transducer and calibration block that

matches the material and expected discontinuities under test.

2. In the

CAL menu, select the proper RANGE and DELAY so that several echoes from the

expected material depth can be viewed.

3. From the

4. Use the

AMP menu, set the DETECT parameter to FULL.

button to set the transducer to SINGLE.

5. Couple the transducer to the calibration block and obtain an echo from a fabricated

discontinuity or the back surface and adjust the

GAIN to set the peak of the echo to about

80% screen height.

6. Adjust the gain to set a reference echo from mid thickness of the calibration block to

about 80% amplitude.

7. From the

PEAK.

8. From the

so that the gate covers the first echo. From the
adjust the
echoes from the first. For instance if a 25mm thick calibration block was being used the
first gate would be set on the first backwall echo and the second gate on the 6

MEAS menu, set the MODE parameter to G1-G2 and the TRIGGER parameter to

GATE1 menu, set the gate to ON +VE and adjust the START, WIDTH and LEVEL

GATE2 menu set the gate to ON +VE and

START, WIDTH and LEVEL so that it covers an echo that is a known multiple of

th

backwall

giving a distance between them of 125mm as shown below:

9. The distance between the echoes is shown in the G-G measurement at the bottom of the

display (in this case 125.54). It is unlikely that the value will be exactly correct as the
velocity of sound in the material will not match one of the preset values. Select a velocity
that is close to the material then adjust it so that the exact distance is obtained as shown
below:

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DFX-625 User’s Guide ~ Flaw Testing

10. Next the calibration needs to take account of the distance between the transducer crystal
and the front face of the transducer by setting the correct
menu change the

MODE to DEPTH.

ZERO value: From the MEAS

11. From the

START, WIDTH and LEVEL values so that the gate covers the 6

GATE2 menu change the MODE to OFF, from the GATE1 menu change the

th

peak as shown below:

12. The distance measurement is shown at the bottom of the display (in this case 151.04).
From the

CAL menu adjust the ZERO value until the correct distance is shown as below:

13. As a final check move the gate across the other echoes to ensure that the correct
distances are shown; From the

GATE1 menu adjust the START and LEVEL parameters so

that the gate covers each echo in turn. Check that the correct values are shown as
below:

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DFX-625 User’s Guide ~Flaw Testing

Now that the DFX-625 has been calibrated it can be used to perform inspections using any of
the techniques described in the following sections.

For weld inspection using an angle beam transducer, follow the instructions in Weld

Inspection Using Trigonometry Mode on page 44.

For storage and printing of A-Scans, refer to A-LOG, A-Scan Storage on page 57

Page 39

DFX-625 User’s Guide ~ Flaw Testing

5.3 DAC Operation

Distance Amplitude Correction curves act as monitoring gate triggering thresholds to
compensate for attenuation and sound beam characteristics. When properly established, the
DAC curve will provide consistent alarming from discontinuities of equal relative size at
different depths in the test piece. Functionality is provided to automatically draw 6dB and
14dB or 6dB and 12dB reference curves below the calibrated curve.

It should be noted that since the DAC function only provides a dynamic alarm threshold
capability, the dynamic range is limited to about 16dB. Therefore, for materials that
attenuate more than 16dB over the depth range of interest, DAC should not be used.
Instead, the TCG function may be more applicable. See TCG Operation on page 42 for the
use of the Time Corrected Gain feature.

Proper use of the DAC feature requires a reference block made from the same material as
that being examined, with flat-bottom or side-drilled holes of the desired size placed at
depths covering the range to be inspected.

To establish a DAC curve, follow the following instructions:

1. Establish the basic calibration of the DFX-625 using the desired transducer and the
proper reference block. From the

MEAS menu, select the DAC feature.

2. Select the
button to select

When in the

MODE parameter by pressing the function button next to it and use the

DRAW. The other parameters will now be CURSOR and POINT. Note:

MODE parameter, only press the button to turn the DAC off. This will

erase any logged echoes.

3. The DAC system is now ready to accept reference points. Position the transducer to give
a maximum echo from the first or topmost reference hole in the reference block. Be
careful to use a consistent amount of coupling and transducer pressure.

4. Use the

and buttons to position the bright cursor bar over the echo from the

reference hole.

5. Press the

OK button to accept the point. A small square will appear as a reference point

on the display showing the peak of the signal just recorded.

6. Repeat steps 5 and 6 for each additional reference hole in the reference block, being
careful to be consistent with the amount of coupling and transducer pressure. A
maximum of 10 points can be recorded for a DAC curve.

7. Press the function button adjacent to
The DAC curve will now be displayed and the other parameters will change to
and

TRIGGER

8. Use the

CURVE parameter and the button to select just the DAC reference curve, the

MODE and use the button to select ON mode.

CURVE

DAC curve along with the -6dB and -12dB curves, or the DAC curve along with the -6dB
and -14dB curves. These additional, automatically generated reference curves provide a
means for evaluating discontinuities smaller than those in the reference block.

9. Use the

TRIGGER parameter to establish the alarm trigger from the DAC curve, the -6dB

curve, or the -12dB/-14dB curve. The latter being whichever one is selected in the

CURVE parameter.

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DFX-625 User’s Guide ~Flaw Testing

If depth measurement is switched on with the DAC feature, the depth mode display below
the A-Trace will show the distance to the echo peak and the relative amplitude to the DAC
reference curve in dB. Note that the relative dB display is dependent on the REF gain
setting, but not the

GAIN setting.

To turn off the DAC feature, select the

button until OFF is indicated.

MODE parameter from the DAC menu and press the

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DFX-625 User’s Guide ~ Flaw Testing

5.4 TCG Operation

The Time Corrected Gain feature provides a means of creating an attenuation curve that sets
the gain in a swept manner as a function of transit time. A properly constructed TCG curve
will compensate for material attenuation and sound beam characteristics so that
discontinuities of equal relative size at different depths in the test piece will give an equal
amplitude response on the display.

Proper use of the TCG feature requires a reference block made from the same material as
that being examined, with flat-bottom or side-drilled holes of the desired size placed at
depths covering the range to be inspected.

To establish a TCG curve, follow the following instructions:

1. Establish the basic calibration of the DFX-625 using the desired transducer and the
proper reference block.

2. From the

3. Select the
button to select

MEAS menu, select the TCG feature.

MODE parameter by pressing the function button next to it and use the

DRAW. The other parameters will now be CURSOR and POINT.

4. The TCG system is now ready to accept reference points. Position the transducer to give
a maximum echo from the first or topmost reference hole in the reference block. Be
careful to use a consistent amount of coupling and transducer pressure.

5. Use the

and buttons to position the bright cursor bar over the echo from the

reference hole.

6. Press the

OK button to accept the point. The POINT parameter will then increment to

indicate the next point. As each point is entered, the gain will change to place the echo
at about 80% amplitude as Shown below:

7. Repeat steps 5 and 6 for each additional reference hole in the reference block, being
careful to be consistent with the amount of coupling and transducer pressure. A
maximum of 10 points can be recorded for a TCG curve.

8. Press the function button adjacent to

MODE and use the button to select ON mode.

The TCG curve will now be displayed, the amplifier gain will now swept, and the other
parameters will change to

9. Use the

CURVE parameter and the button to select ON or OFF for the display of the

CURVE.

TCG curve.

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DFX-625 User’s Guide ~Flaw Testing

NOTE: A TCG curve cannot be drawn while in RF display mode (
parameter,

RF value), but can be activated. Therefore, if TCG is desired in RF display mode,

AMP menu, DETECT

draw the curve in rectified mode first and then switch to RF. It should be noted that the
range of TCG is limited only by the dynamic range of 40dB.

Page 43

DFX-625 User’s Guide ~ Flaw Testing

5.5 Weld Inspection Using Trigonometry Mode

The trigonometry mode provides a convenient method for measuring the location of
discontinuities when inspecting welds with angle beam transducers. Essentially, the
trigonometry mode uses the thickness gauging features of the DFX-625 to calculate the
surface distance and depth to a discontinuity from the actual beam path measured. This is
accomplished by calibrating the trig mode with the actual refracted angle of the transducer
being used. Additionally, the thickness of the test piece must be established in the menu in
order to calculate depth and surface distance when using multiple skips in angle beam
testing. The measurements being calculated are depicted in the following diagram:

These measurements are displayed below the A-Trace on the DFX-625 as follows:

Beam path distance B from the central exit point on the transducer to the

discontinuity, the sum of B1 and B2 in double skip mode.

Surface distance S from the central exit point on the transducer to a point directly

above the discontinuity on the test piece. By entering the distance from the Front of
the Probe to the emission point in the PROBE menu, This distance may be displayed
relative to the front of the probe, which is usually more convenient.

Depth distance D from the surface on which the transducer rests to the discontinuity.

Depending on the measurement technique being used there is an additional value displayed
on the right of the measurement bar as shown below:

The example shows above the normal height value as a percentage of full screen; in this
case 85%. If DAC is being used then the user has the choice of displaying either dB, %FHS
or %DAC. If DGS/AVG is being used then ERS is displayed in the right hand side.

It is important to note that discontinuities in welds can be discontinuous and can extend over
a distance. The measurements made will, therefore, be close approximations to the
discontinuity if the user properly calibrates the DFX-625 and uses care to locate the desired
peak amplitude signal to which a measurement is made.

To calibrate and use the trigonometry mode, follow the following instructions:

1. Using a suitable IIW or other calibration block, measure and establish the central sound
beam exit point and actual refracted angle for the transducer being used.

2. Establish the zero and velocity (span) for the transducer and material under test using the
A-CAL procedure described in A-Cal on page 63. Use a suitable calibration block that
has two drilled holes representing the thin to thick range of thickness expected in the test
piece. In the

MEAS menu set the TRIGGER parameter to PEAK. As in any ultrasonic

thickness measuring method, it is important that the calibration be performed using a
calibration block of the same material as that being inspected. Alternately, if you know
the velocity of sound in the test piece, you may calibrate using the A-CAL method on a
different material and then set the velocity parameter.

3. Set the

START and WIDTH of Gate1 to encompass the desired testing region.

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DFX-625 User’s Guide ~Flaw Testing

4. From the Main menu, select

5. Set the

6. Select the

TRIGGER parameter to PEAK.

ANGLE parameter and using the and buttons, set the refracted angle of

MEAS and place the MODE to TRIG.

the transducer measured in step 1 above.

7. Select the

THICK parameter and using the and buttons dial in the thickness of the

test piece. You may have to readjust this parameter if the test piece had varying
thickness and you are using a multiple skip mode of angle beam testing.

8. When measuring a discontinuity, position the transducer so as to obtain the maximum
amplitude signal before recording the readings. A typical TRIG mode display is shown
below.

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DFX-625 User’s Guide ~ Flaw Testing

5.6 Weld Inspection Using the AWS Menu

The AWS menu provides a means for evaluating discontinuities when inspecting welds in
accordance with the American Welding Society’s Structural Welding Code, ANSI/AWS D1.1-

94. The user is referred to the AWS standard for full details of the method.

The AWS menu provides a convenient method of automatically calculating the “Indication
Rating” (IR) as defined by the standard. The AWS menu can be used in conjunction with the
trigonometry mode which will simultaneously indicate beam path, surface distance and depth
distance at the bottom of the graticule. The AWS menu will not operate with either the DAC
or TCG switched on.

To set up the AWS measurements, perform the following:

1. Calibrate the DFX-625 for weld testing and set up the trigonometry mode by following the
steps in Weld Inspection Using Trigonometry Mode on page 44.

2. From the

MEAS menu, select AWS and place the MODE to SET.

3. Highlight REF on the menu and set to the desired reference level, usually 80% of full
screen height.

4. Place the probe on the test block and obtain the maximum signal from the reference
indication.

5. Place the cursor over the indication by selecting

CURSOR ADJUST and using the and

arrow keys.

6. With the signal maximized, press the

OK key.

The DFX-625 is now calibrated to make Indication Rating measurements in accordance with
AWS D1.1-94. To use the AWS mode, do the following:

1. On the

2. Ensure that the gate and measurement (

AWS menu, highlight MODE and select MEAS.

TRIG) function are operative and properly

adjusted.

3. When the AWS menu is selected and a signal is in the gate, the sub-menu boxes will
show the resulting AWS measurements as follows:

AFRGILIR −−=

(Indication Rating = Indication level – Reference Gain – Attenuation Factor)

Where:

IL: Indication Level The dB setting required to bring an indication to

the reference level.

RG: Reference
Gain

The dB setting of the calibrated reference
indication as a function of the reference standard
and probe being employed.

AF: Attenuation
Factor

The attenuation factor required by the AWS
standard and is: Depth in inches minus 1,
multiply by 2 and then rounded to the nearest ½
dB.

IR: Indication
Rating

The difference in dB between the indication and
the reference gain with attenuation factor
correction.

It is not necessary to bring the indication to the reference level to obtain the correct
measurement information as the DFX-625 adjusts for gain offset. However, to ensure the
best accuracy of calculation, it is advised to adjust the indication to be above 40% and below

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DFX-625 User’s Guide ~Flaw Testing

100% of full screen height. In addition, in the AWS mode, gain offset is shown as +/- dB from
reference as opposed to absolute gain.

Page 47

DFX-625 User’s Guide ~ Flaw Testing

5.7 Evaluation of Pipe Imperfections using API 5UE

The DFX-625 is able to assist the user in making measurements in accordance with the
American Petroleum Institute (API) Recommended Practice for Ultrasonic Evaluation of Pipe
Imperfections using the Amplitude Distance Differential Method (ADDM). Users are referred
to the publication: “API Recommended Practice 5UE, Second Edition, June 2005”

The ADDT employs a combination of amplitude comparison and 6dB drop techniques to
determine the radial depth of an imperfection. The technique is based on the premise that
radial depth of an imperfection affects both the amplitude of the received echo signal and the
differential time of flight of the transmitted ultrasonic wave as it passes over the imperfection.

The first step is to perform a standardisation using a reference indicator such as a notch of a
known depth or a through drilled hole. It is assumed that the Masterscan had been setup
with the correct values for the transducer and specimen being used for the inspection.

First turn on

GATE1 from the CAL menu and position it on the display so that it will cover the

signal that will be produced by the reference indicator; the height of the gate is not important.
Ensure that the signal will be between 5% and 100% of full screen height. Select

MEAS menu and select PEAK by pressing the button twice then capture the

the

API from

reference signal and the following display should be shown:

Once the desired signal is obtained press the

OK button and the k factor (a derived factor for

calculating depth) is calculated and displayed as shown:

The DFX-625 automatically goes into

FREEZE mode. Pressing the OK button again puts the

API facility into measurement mode as shown below. The k value is displayed but cannot be
changed while in measurement mode.

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DFX-625 User’s Guide ~Flaw Testing

To take measurements select

PEAK mode by pressing the button twice and capture the

echo dynamic signal; once the desired signal has been captured press the OK button. The
di value is calculated and displayed as shown below:

Once the measurement has been made, pressing the

To take the next measurement select peak mode by pressing the

OK button clears the current reading.

button twice.

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DFX-625 User’s Guide ~ Flaw Testing

5.8 DGS/AVG Operation

The DGS (Distance Gain Size) method, often known by its German acronym AVG
(Amplituden Vergleichs Größe), allows a theoretical model to be used for assessment of
ultrasonic echoes.

The DGS/AVG method allows flaw sizing and distance compensation without requiring the
large range of reference standards for each test which would be required in order to
establish a measured DAC curve, or to set up a TCG correction.

The relative response from ‘Equivalent reflectors’ of different sizes at different distances can
be predicted mathematically from the probe effective diameter, frequency and near field
length (a function of the first two). Probe sensitivity can be calibrated from a single
measurement (usually the back wall echo)

DGS/AVG has several limitations:

• It is a predicative method, so only works in ‘standard’ configurations where the

mathematical model is valid

• It must be applied with care with non-circular probe elements as we have to

approximate an ‘effective diameter’

• It does not work well on broadband probes, where the frequency is not well defined.

• It should only be applied to single element probes, as dual element probes have an

inherent focus.

Corrections may be required for several factors:

• Internal time delays within the probe

• Attenuation with distance, both within the material to be tested and the reference

block, if significant over the distances involved.

• Transfer correction, e.g. if the tested material has a significantly rougher surface than

the reference block

• When using an angle probe and calibrating on a curved reflector (e.g. V1 or V2 Block)

a correction must be applied.

5.8.1 Theory

For a naturally focussed probe of given frequency and size, the general beam profile can be
defined in terms of a ‘normalised’ standard curve, scaled by the Probe ‘effective diameter’
and near field length.

The near field length is defined by the equation:

22

−

D

=

N

Where

The echo height from a small (much less than sound field width) reflector will be proportional
to its size.

λ

EFF

()

4

D is the probe effective diameter and is the wavelength (Velocity/Frequency)

λ

EFF

The echo height from a given reflector in the far field (distance from the probe greater than 2­3 Near Field Lengths (NFL)) will be inversely proportional to the square of its distance from
the probe.

It is therefore possible to define a standard relationship, knowing the basic probe
parameters, which only need be corrected for the sensitivity of the probe by measuring the
response from a known reflector.

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DFX-625 User’s Guide ~Flaw Testing

The picture shows a ‘general’ DGS/AVG diagram plotted on logarithmic scales, Relative gain
in dB, Distance as a multiple of Near Field Length, The various curves represent the signal
from an Equivalent Reflector Size (ERS) expressed as a multiple of the effective probe
diameter.

Note that the signal from the back wall echo (‘infinite’ reflector) falls off with distance, rather
than with the square of distance.

5.8.2 DGS/AVG Frequency, NFL and ERS

Press MENU then the function button next to MEAS and select the AVG menu, MODE should

OFF

be

FREQ and NFL from the probe parameters. (It is recommended that figures from specific

Set
probe test results, rather than generic data sheets, be used where possible, as typical
manufacturing variations are sufficient to affect the accuracy of the results.)

Desired test sensitivity (ERS) may also be set now. (This can be adjusted later)

5.8.3 DGS/AVG dVK, Delay

Set MODE to SET PRB

dVK (V

This value allows the use of a curved surface to provide a back wall echo for use as a
reference signal, thus the same reference block can be used irrespective of probe angle.

) – Curvature Correction Factor in dB

K

The amplitude correction factor shows by how many dB the echo from the cylindrical surface
is larger or smaller than the echo from a flat backwall, normal to the probe field axis at the
same distance.

This value is subtracted from the gain to compensate for the focusing effect of the curved
reference reflector. It should be entered as a positive or negative value as expressed in the
probe data sheets.

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DFX-625 User’s Guide ~ Flaw Testing

Probe datasheets typically express thus value as VK1, for use with the K1/V1 calibration
block, or V

for use with the K2/V2 calibration block. These calibration blocks are

K2

specified in standards EN12223 / DIN54122 / BS2704

DELAY – Probe Delay Velocity, in meters per second

This is the velocity of compressive sound waves in the material of the probe wedge. It is
used mostly in angle probes but also in zero degree compression probes which have a delay
line. This wedge material is typically Perspex, which has a compressive sound wave velocity
of 2700 m/s.

It is used, in conjunction with the probe zero and the specimen velocity, to calculate the
Sound field equivalent length, this being the effective distance of the crystal to the test
piece/wedge interface.

NOTE: For DGS/AVG to work accurately the probe zero must be set correctly.

5.8.4 DGS/AVG T-Loss, Ref dB and Mat dB

Change MODE to ‘SET ATT’. This menu allows the operator to enter attenuation parameters
relating to the materials of the Calibration Block and the item under test, these parameters
being:

T-LOSS – Transfer Loss, in dB.

This is the loss due to surface roughness, poor coupling etc between the probe and the
object under test. Generally it can be assumed that the Reference block will have a clean
surface , but this may not apply to the object under test, methods exist for measuring this,
experienced based ‘rules of thumb’ are also commonly used.

REF dB/m – Reference Material Attenuation, in dB per meter

Attenuation of ultrasound in the Reference (Calibration) block material in dB per Meter

MAT dB/m – Test Material attenuation, in dB per meter

Attenuation of Ultrasound in the material of the object under test in dB per Meter

REF dB/m and MAT dB/m are used where the ultrasound attenuation in these materials

The
is such that it would cause a disparity in signal heights between similar reflectors in these
materials. At long path lengths these factors become very important.

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DFX-625 User’s Guide ~Flaw Testing

5.8.5 DGS/AVG ~ TBVEL, REF TYPE and REFSIZE

Change MODE to SET REF

TBVEL – Reference (Calibration) Block Velocity, in meters per second

Reference (Calibration) Block Velocity, in meters per second. This parameter is used
internally.

It will take the same range of values as the Velocity parameter.

NOTE: This parameter MUST be entered. The Wavelength, which is calculated from this
velocity and the Probe frequency, is critical to the DGS/AVG calculations.

REF TYPE – Reference Reflector Type

The user can select one of a number of different reference reflectors.

In this implementation, these have been derived from EN 583-2:2001 Annex B.

These reflector types are:

• BWE – Back Wall Echo

• FBH – Flat Bottom Hole

• SDH – Side Drilled Hole

Reference type SDH is converted internally to the equivalent DSR diameter according to the
formulae in EN 583-2:2001 Annex B.

When using reference reflectors of type SDH or SSH, it is essential to select the correct
Calibration block velocity (

TBVEL). This is because the calculations for the equivalent DSR

use the wavelength of sound that is calculated from the Calibration Block velocity and the
probe frequency.

REFSIZ – Reference Reflector Size, diameter in mm

Allows the user to enter a diameter, in mm, for a reflector. The reflector type is set using the

REF. TYPE parameter above.

The set will automatically compensate for the varying ‘reflectivity’ of different reflector types
as specified by the
as

REF TYPE: SDH and REFSIZ: 3.0

REF TYPE parameter. Thus a 3 mm side drilled hole should be entered

In this implementation, a diameter of 0 (zero) is used to represent a reflector of infinite size
and is expressed as

BACKWALL or INFINITE.

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DFX-625 User’s Guide ~ Flaw Testing

5.8.6 DGS/AVG Calibration

The calibration of the DGS/AVG system sets the Probes ‘absolute sensitivity’ based on the
response from the reference block.

Changing any parameters relating to the reference echo will invalidate the calibration, which
must then be repeated. The current version of the software does not enforce this – it is the
responsibility of the operator.

MODE to SET SIG

Set

Place probe on reference block and maximise echo, select

CUSROR ADJUST and use

up/down keys to centre the selection bar over the echo. Check echo still maximise and Press

OK.

The instrument will adjust gain as necessary to get a good echo reference and then perform
the necessary sensitivity calculation; the curve will then be drawn.

DGS/AVG is now on. In this screen it is possible to adjust the curve ERS level (the
instrument will redraw the curve, but a new calibration is not required) and select either the
Curve or Gate as the measurement reference.

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DFX-625 User’s Guide ~Flaw Testing

5.8.6.1 Adjustment

When the DGS/AVG has been calibrated it is possible to leave the DGS/AVG menus and
adjust other settings of the instrument, for example range and gate settings.

Gain may be adjusted with understanding – Changing the Gain setting will remove the
correlation with the DGS/AVG curve, so should only be done in accordance with a
specification , for example to compensate for varying material conditions (better done with
the T-LOSS function). If it is desired to change the gain to give a larger signal (for example at
long range) the REF gain should be adjusted. This will change the curve by an equivalent
amount and preserve the measurement accuracy.

Increasing REF Gain by 6dB moves curve and preserves measurement

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DFX-625 User’s Guide ~ Flaw Testing

Decreasing Gain by 6dB returns to original height, but loses measurement

The Reference gain may be selected by pressing the

REF/GAIN Button. (DGS/AVG is only

appropriate for Single probe mode)

When the Display Range or REF Gain is changed the DGS/AVG curve will recalculate at
each step. If the settings must be changed by more than one or two steps it may be more
convenient to Switch DGS/AVG off, Change REF gain and range etc as needed, and then
switch DGS/AVG on again. This will not invalidate the curve provided the following are not
changed:

FREQ, NFL, dVK, DELAY, REF dB/m, TBVEL, REF TYPE, REFSIZ, (new REFERENCE

Entered), Probe Zero, Filter, Contour, TX Parameters (Width or Voltage,) or Probe Angle.

The following should not be used in DGS/AVG Mode:

Detect Modes other than Full Wave, non-zero REJECT, Dual probe mode, Smooth,

A_CAL (other than for initial setup before using DGS/AVG), DAC, TCG, AWS,

5.8.7 Measurement

Having set up the DGS/AVG system, it is possible to use the measurement system to
calculate an Equivalent Reflector Size for the flaw.

This is achieved by using Gate 1 to identify the flaw indication and the DEPTH measurement
mode to calculate its equivalent size. This Equivalent Size is calculated as the Test
Sensitivity (ERS value) multiplied by the Ratio of the Signal height to the DGS/AVG curve
height at that distance. It is displayed in place of the signal amplitude (%FSH) as a diameter,
in mm.

It is also possible to ‘size’ the flaw in terms of dB with respect to the DGS/AVG curve. This is
achieved by increasing, or decreasing, the set gain until the peak of the flaw signal lies on
the DGS/AVG curve. The difference in Gain required can then be read directly from the
displayed Gain Value.

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DFX-625 User’s Guide ~Flaw Testing

5.9 A-LOG, A-Scan Storage

The A-LOG feature provides for storage, recall and printing of A-Scans with all of the
instrument settings. Up to 800 A-Scans and their settings can be stored. This feature is
useful to record an indication for later review or for printing a hardcopy. In addition, recalling
an A-Scan and its settings will allow for easy follow-up inspection of the same indication on
the test piece. Simply unfreeze the display after recalling and the DFX-625 is ready to repeat
the same inspection. Be sure to use the same transducer that was use for the original
recording.

5.9.1 To Store An A-Scan:

1. Establish the basic calibration of the DFX-625 using the desired transducer and the
proper reference block.

2. From the

3. Select the
and

location is

MEMORY menu, select the A-LOG feature.

STORE parameter by pressing the function button next to it and use the

buttons to select a store location. The STATE parameter shows whether the store

VALID (used) or EMPTY. Be careful not to store over a valid location unless

you desire to erase what is there and replace it with the current A-Scan and settings.

4. Select the
button to select

MODE parameter by pressing the function button next to it and use the

STORE.

5. Obtain a desired echo from a discontinuity or reference block.

Optionally press the

6. Press the

OK button to store the waveform and instrument settings; the display will show

button to freeze the display before storing it.

a dialogue box:

7. At the

CONFIRM prompt, press the OK button again to store the A-Scan or press the

button to continue without storing the A-Scan.

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DFX-625 User’s Guide ~ Flaw Testing

8. After pressing the OK button a second time, the NOTES window opens automatically to

allow the creation of any desired notes for the stored A-Scan and its settings. See the
section Adding NOTES to PANEL and A-LOG sets on page 33. When finished adding
notes, press the function button next to the STORE parameter to return A-LOG menu.

5.9.2 To Recall an A-Scan:

1. From the MEMORY menu, select the A-LOG feature.

2. Select the
and

shows whether the store location is

3. Select the
button to select

4. Press the
couple of seconds at which time the display will be in

STORE parameter by pressing the function button next to it and use the

buttons to select the desired store location to be recalled. The STATE parameter

VALID (used) or EMPTY.

MODE parameter by pressing the function button next to it and use the

RECALL.

OK button to recall the waveform and instrument settings. This may take a

FREEZE mode and the number of

the A-LOG is displayed at the bottom of the display. To return to normal testing mode

with the recalled settings, press the

button.

5. Alternately, you may review the notes pages stored with each A-LOG to determine which
set you want to recall. Set the
through each one to view the

OK button to recall it. To remove the notes review window, set the MODE back to STORE,

RECALL or DELETE.

MODE to LIST and using the STORE parameter, move

NOTES page. When the desired A-LOG is found, press the

5.9.3 To Delete a Stored A-Scan

Follow the steps above but set the MODE parameter to DELETE and then press the OK
button. At the CONFIRM prompt, press the OK button again to delete the A-Scan or press the

button to continue without deleting the A-Scan.

To edit notes in an A-LOG, press the function button next to the
then follow the instructions in the section on Adding NOTES to PANEL and A-LOG sets on
page 33.

EDIT NOTES parameter and

NOTE: When notes are displayed, the menu cursor buttons are disabled. Switch off list
mode to change to another menu.

5.9.4 REF, Reference Waveform Comparisons

This feature allows the user to select a waveform from one stored in the A-LOG menu, and to
display this reference waveform on the graticule along with the real time waveform. This
makes easy comparisons possible between an expected signal response (the reference
waveform) and that obtained from the test piece.

5.9.5 To Recall an A-Scan as a Reference Waveform:

1. In order for a reference waveform to be recalled, the required trace must first be stored
into an A-LOG store.

2. From the

3. Select the
and

location is

4. Select the

button to select RECALL. If set to LIST, the note associated with the reference

waveform will be displayed.

5. Press the
waveform will be a different color as compared to the real time waveform, depending on
which display color is chosen.

MEMORY menu, select the REF feature.

STORE parameter by pressing the function button next to it and use the

buttons to select a store location. The STATE parameter shows whether the store

VALID (used) or EMPTY.
MODE parameter by pressing the function button next to it and use the or

OK button to display the reference waveform on the graticule. The reference

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DFX-625 User’s Guide ~Flaw Testing

6. To remove the reference waveform, set the

MODE to OFF and press the OK button.

NOTE: When the reference is recalled, no setting parameters are changed. Therefore, if the

RANGE or DELAY are changed, the reference signal will not match the real time waveform.

This means that the

RANGE and DELAY used for storing the reference waveform in A-LOG

must match that used for the comparison of real time signals to the reference waveform. The
reference waveform cannot be displayed in video colors 0 and 1 (All white and all yellow).

5.9.6 Contour & Peak Echo Dynamics

Contouring is a technique that enables the significant echoes to be enhanced by extending
the trailing edge of the echoes thus making them appear wider than they actually are making
the DFX-625 operate more like an older analogue flaw detector. Only the trailing edge is
modified so that depth measurements using FLANK and PEAK are not effected. Contouring
is automatically optimised in the DFX-625:

During flaw testing it is sometimes difficult to determine the exact peak of a discontinuity
echo due to its geometry, coupling and surface anomalies and part geometry. The DFX-625
incorporates a Peak feature that, while activated, stores all of the signal excursions on the
display using a fill technique.

In addition to providing an effective method of capturing peak echo information, the Peak
mode is useful for crack tip diffraction methods in angle beam weld inspection. It the case of
crack tip diffraction, the extent of a crack type discontinuity can be inferred by the positional
excursions of the signal as it reflects from both tips of a crack. Thus, as the transducer is
moved past the indication, the signals will be “filled-in” on the display and the resultant width
of the envelope or “echo dynamic pattern” will infer the crack length.

To use the echo dynamic pattern feature, position the transducer just off one side of the

indication. Press the

button twice to activate the Peak mode which is indicated by a
box-displaying PEAK below the graticule. Move the transducer past the indication to fill-in
the envelope pattern. In the case of angle beam testing, it is advisable to rotate the
transducer slightly and move it from side to side while moving forward past the indication.
This will assure the capturing of all amplitude and distance information. An example of peak
echo mode capture is shown below:

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DFX-625 User’s Guide ~ Flaw Testing

To return the display to normal mode, press the

button a third time. This will erase the
envelope pattern and return the instrument to the instantaneous mode of display. While the
display is showing the dynamic echo pattern, it is possible to record the A-Scan as indicated
in A-LOG, A-Scan Storage on page 57.

Page 60

DFX-625 User’s Guide ~Thickness Gauging

6 Thickness Gauging

6.1 Basic Thickness Gauging

Accurate and reliable thickness gauging requires three important considerations:

a) Proper transducer selection

b) An accurate reference block of the same material as that being tested, and

c) Proper calibration of the instrument.

There are three types of transducers used in ultrasonic thickness gauging, all employing the
straight or longitudinal beam method. The single element contact transducer is used for
general purpose thickness gauging where material thickness is generally expected to be
above 2.5mm. The delay line contact transducer is used for measuring thin material down to

0.5mm where the surfaces are clean and parallel. The dual element contact transducer is
used for moderately thin materials down to about 1.0mm where the surfaces may be irregular
and not necessarily parallel. The dual transducer is most commonly used for corrosion
thickness inspection where its ability to obtain echoes from pitting is superior. Nevertheless,
dual transducer inspection on corroded materials is nowhere near as accurate as single
element and delay line inspection, due to the nature of the material under test. In addition,
the dual element transducer usually incorporates a slight included angle on both the transmit
and receive side, resulting in a small non-linearity of the measurements. For this reason,
dual transducer thickness testing is usually calibrated and performed over a limited thickness
range.

Regardless of the type of transducer used, it is important that it be specifically designed for
thickness gauging. This means that it must have broadband or highly damped
characteristics that provide a sharp leading edge. Otherwise, amplitude variations of the
signals can cause half-wavelength errors due to smaller “build-up”

The next requirement for thickness gauging is a calibration or reference block. This block
should be made of the same material as the components to be inspected. In other words, it
should have the same sound velocity and attenuation characteristics. The calibration block
should have parallel machined surfaces representing the thickness range to be inspected.
Although two thicknesses representing the minimum and maximum values are sufficient for
calibration, it is recommended that the calibration block have four sections covering the
range anticipated. This will allow for verification of the calibration.

It is possible to calibrate the DFX-625 using a generic test block and only one known sample
thickness of the material under inspection. This is a less desirable method because there is
no way of verifying the calibration. With this method, the calibration would first be performed
on the generic test block, which would have three to four sections covering the expected
thickness range. Essentially, calibrating on the generic block would set the transducer zero
point. Then the DFX-625 Velocity would be adjusted on the known sample of the test
material until the thickness readout matched the known thickness. This established the
sound velocity for the test material.

Finally, it is necessary to establish the proper calibration of the DFX-625 in order to assure
accurate and reliable thickness testing. The essence of this calibration is to set the pulser
and amplifier characteristics to provide sharp leading edges on the echoes. The following
are the essential steps for basic thickness gauging:

1. Select the appropriate broadband transducer and calibration block that matches the
material under test.

2. In the
of thickness can be viewed.

CAL menu, select the proper RANGE and DELAY so those echoes from the range

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DFX-625 User’s Guide ~ Thickness Gauging

3. From the AMP menu, set the FREQ to the nominal value of the transducer and set the

detection mode to

RF.

4. Use the

DOUBLE for dual element transducers.

button to select SINGLE for delay line and single element transducers and

5. Couple the transducer to a mid-range thickness section on the calibration block and
obtain an echo.

6. Adjust the gain to set the echo at about 80% amplitude and increase the

REJECT

parameter to remove any undesirable noise from the baseline.

7. From the

GATE1 menu, set the gate to ON +VE and adjust the START and WIDTH so that

the gate encompasses the thickness range of interest. Place the transducer between the
thin and thick area on the calibration block to verify proper coverage. Adjust the

LEVEL

parameter to about 30% of full screen.

8. From the

FLANK.

9. If desired, set the
held in the display. Reset by using the

10. If desired, set the

MEAS menu, set the MODE parameter to DEPTH and the TRIGGER parameter to

T-MIN parameter to ON so that the thinnest reading obtained will be

or buttons.

HUD parameter to ON to display the thickness in a large window at the

top right of the graticule.

11. To calibrate the DFX-625 for thickness readings, follow the steps outlined in A-Cal on
page 63. Alternately, you can use an iterative process from the

ZERO on the thinnest calibration block sample and the VELOCITY on the thickest sample.

Using this technique, you must repeat

ZERO to VELOCITY several times until the two

CAL menu of setting the

values are correct.

When using a delay line transducer, there are two modes of measurement:

a) Interface to first return echo, and

b) multiple echo mode which usually measures from the first to the second return echoes
after the interface echo.

1. Follow steps 1-10 above.

2. From the

MEAS menu, set the MODE to E-E for echo to echo measurement. You will

notice that a second gate bar appears below gate 1 and that its start point is slightly to
the right of gate 1. This is the Blocking gate explained below.

3. For measuring from interface to first echo, position the start of gate 1 before the interface
echo. Using the

BLANK parameter in the MEAS menu, position the start of the second

gate just after the interface echo but before the thinnest expected first echo.

4. For measuring multiple echoes after the interface, position the start of gate1 just after the
interface echo. Using the

BLANK parameter in the MEAS menu, position the start of the

second gate just after the first echo but before the thinnest expected second echo.

5. The

BLANK parameter determines the blanking or starting position of the second gate

relative to the starting position of gate1. This prevents noise and spurious echoes
associated with the interface or first echo from terminating the measurement and
producing a false reading.

For storage and printing of thickness readings, refer to T-LOG Thickness Storage on page 65
and T-FN Thickness Log Editing and Printing on page 68.

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DFX-625 User’s Guide ~Thickness Gauging

6.2 A-Cal

A-CAL is an automated calibration feature for thickness gauging applications or when
measuring depth to an indication in flaw testing.

In order to achieve proper calibration for measuring time-of-flight in ultrasonic testing, two
factors must be known; the velocity of sound in the material under test, and the offset of the
transducer caused by wear face and phase shifts.

Conventional thickness calibration technique usually requires setting the zero (offset) and
span (velocity) using an iterative technique. This means alternately placing the transducer
on a thin sample to set the zero and a thick sample to set the span. This process is repeated
several times until both readings are correct. The reason for this is that raising the span will
also raise the zero.

The A-CAL feature automates this process so that only two readings are required, one on the
thin sample and one on the thick sample. The DFX-625 then calculates the correct offset
and span factors and sets the velocity and zero. Any time the test material is changed
(velocity) or the transducer is changed (zero); this procedure must be repeated. Using this
calibration function results in faster calibration of the instrument and more accurate
measurements.

The A-CAL calibration procedure is as follows:

1. Select a test block of the same material as that being inspected, with reference thickness
covering the minimum to maximum thickness expected in the test parts. The difference
between the thick sample and the thin sample should be no less than five to one.

2. From the main menu, select

CAL and adjust the RANGE and DELAY so that the thin and

thick reference echoes show on the display.

3. From the
and

4. From the main menu, select

5. From the

6. Select

CAL menu, select GATE1 and place the STATE in ON +VE. Adjust the START

WIDTH of the gate to encompass the echoes from the thin and thick samples.

MEAS and place the MODE to DEPTH.

CAL menu, select the A-CAL menu.

DIST1 using the adjacent function button. Adjust the value using the and

buttons to the known thickness of the thin sample.

7. Place the transducer on the thin reference sample and obtain an echo. Adjust the gate
start if necessary to obtain distance readout of the echo.

8. Press the

9. Select

OK button to log the echo.

DIST2 using the adjacent function button. Adjust the value using the and

buttons to the known thickness of the thick sample.

10. Place the transducer on the thick reference sample and obtain an echo. Adjust the gate
width if necessary to obtain distance readout of the echo.

11. Press the

12. Select

13. Press the

DIST1 and DIST2 values can be stored when the calibration information in PANEL and A-

The

functions are stored. This overcomes the need to set these values and gate positions

LOG

OK button to log the echo.

ACCEPT CAL using the adjacent function button.

OK button. The transducer zero and velocity will now be adjusted.

every time a calibration is desired. Once established, all that is required is to obtain each
echo and press

OK, and then press OK on ACCEPT CAL and the instrument is calibrated.

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DFX-625 User’s Guide ~ Thickness Gauging

If a delay transducer is used set DIST1 to 0.0 and use the interface echo as the thin reference
echo. The instrument will then set the transducer zero to compensate for the delay line.

Once calibrated, it might be desirable to record the velocity and zero values from the CAL
menu for future reference. Note that this is a convenient method for determining the velocity
of sound in an unknown material. Once the DFX-625 is calibrated on a known material, all
that needs to be known is one fixed thickness point and the velocity can be determined.

6.3 TCG for Reliable Gauging

As previously mentioned, reliable thickness gauging requires that the shape of the echoes be
consistent with sharp leading edges. When measuring the thickness of material with higher
than normal attenuation to ultrasonic energy or a wide thickness range, it is difficult to
maintain proper characteristics of the echoes. One way to overcome this is to use the Time
Corrected Gain feature of the DFX-625. TCG can improve the reliability of thickness gauging
by increasing the amplitude of echoes from thicker sections of the test material so as to
maintain the correct detection threshold on the leading edge. The objective is to equalize the
amplitude of echoes over the entire thickness range to be expected.

To set up the TCG feature, refer to TCG Operation on page 42.

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DFX-625 User’s Guide ~Thickness Gauging

6.4 T-LOG Thickness Storage (Numeric)

The T-LOG menu provides a convenient method to store thickness readings for record
keeping and analysis. The maximum number of readings that can be stored is 8,000. When
using the default
each thickness reading is stored under a three level code. The top level is the
number which can be 1 to 14. This is followed by the
set between 1 and 8,000. Last is the reading number (
1 and 8,000.

This hierarchy of coding for a thickness reading allows readings to be associated with
physical characteristics of the component under inspection. Thus, it is up to the user to
devise a scheme of assigning blocks, locations and readings to the inspection, keeping in
mind the maximum combination of 8,000.

To store readings, follow these simple steps:

1. Set up the instrument for the thickness measuring mode as described in Basic Thickness

Gauging on page 61.

NUMERIC mode selected from the T-FN function on the MEMORY menu,

BLOCK

LOC (location) number which can be

NO) itself which can also be between

2. From the

3. Use the corresponding function buttons to select

MEMORY menu, select the T-LOG menu.

BLOCK, LOC, and NO in turn and or

the value to obtain the desire location number for storing the thickness.

Note: If a value shows in the

THICK box, then a reading has already been stored in that

location. Continuing will overwrite that value with the new thickness reading.

4. Obtain the desired thickness reading and press the
that the

5. To review a reading, select the desired
value in the

NO value automatically increments to the next reading number.

BLOCK, LOC and NO to identify the location. The

THICK box shows the reading stored for that location. To print or delete

OK button to log the reading. Notice

readings, use the T-FN menu.

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DFX-625 User’s Guide ~ Thickness Gauging

6.5 T-LOG Thickness Storage (Sequential & Download)

The Sequential mode of thickness storage allows readings, locations and notes to be
transferred between a computer and the DFX-625.

Typically, the user would create a thickness location sequence on the computer and
download it to the DFX-625, which can then be used to guide the operator when collecting
thickness readings. The collected readings could then be uploaded to the computer for
further analysis and storage, releasing the DFX-625 to collect readings from another
component. When a component is re-inspected, the historical readings can be downloaded
to the DFX-625, providing the operator with an instant check of thickness variation while
collecting new readings. The new readings can then be downloaded back to the computer
for analysis, storage and printing.

To use the Sequence/Download mode, follow these steps:

1. Using suitable software or text editor, generate a location sequence on the host
computer. Each location is comprised of a location number (1 to 8,000) and a text string
of 32 characters. The text strings of 32 characters are subsequently displayed on the
DFX-625 as two lines of 16 characters each in a window at the top left of the screen,
when the DFX-625 is in the Sequence mode. Generally, the first 16 characters are used
to identify the location so as to direct the operator to the proper point for a thickness
reading. The second 16 characters are for general use and can be used for the historical
readings or baseline readings if this is the first inspection of the component. Character
position 23 is reserved for, and identifies the

mode is ON.

SET

PANEL store (1 to 20) to RECALL if AUTO-

2. Turn on the sequence mode by selecting the
menu using the arrow buttons, pressing the function select button next to the

option, and using the

button to select the SEQUENCE mode. Once selected, the

T-FN function from within the MEMORY

ID MODE

graticule will reduce in size and a window is drawn on the top left of the screen next to
the HUD window which is automatically switched on. The location and thickness data will
be shown in the window if any data has been downloaded to the DFX-625. Alternately,
the Sequence mode can be turned on by a command from the host computer.

3. Set up the instrument for the thickness measuring mode as described in Basic Thickness

Gauging on page 61.

4. From the

5. If auto calibration is desired, press the function select button next to the
option, and using the

downloaded location data contains a
in the data text string, corresponding to a

Note: If a value shows in the

MEMORY menu, select the T-LOG menu.

AUTO SET

button, select ON. AUTO SET can only be used if the

PANEL store value (A to T) at character position 23

PANEL store location (1 to 20).

THICK box, then a reading has already been stored in that

location. Continuing will overwrite that value with the new thickness reading.

6. Obtain the desired thickness reading and press the
that the

LOC value automatically increments to the next reading number. Any historical

OK button to log the reading. Notice

reading downloaded from the computer will show in the window on the screen for
comparison purposes.

7. To attach one of the four available notes with the reading, press the function select button
next to the

PITTING, POOR S/C (poor signal/couplant), or NO BWE (no backwall echo).

8. To review a reading, select the desired
the

THICK box shows the reading stored for that location. To print or delete readings, use

the

T-FN menu.

NOTES option, and using the or buttons, select OBSTRC (obstruction),

LOC number to identify the location. The value in

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DFX-625 User’s Guide ~Thickness Gauging

9. Once all of the readings for a component have been taken, they can be uploaded to the
computer for further analysis and storage. The location data transferred is the 32
character string associated with the location, the thickness value, the units of measure,
and the notes. Locations with a blank note will contain the characters “OK.”

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DFX-625 User’s Guide ~ Thickness Gauging

6.6 T-FN Thickness Log Editing and Printing

The T-FN menu provides capability for the printing and deletion of thickness reading stored
with the T-LOG feature. With the T-FN feature, it is possible to print or delete a single
location reading, all locations within a block, or all blocks.

6.6.1 To print a single Location:

1. Make sure that the printer is properly connected to the serial or USB port, turned on and
on-line.

2. Select the

3. Select the
button to select

4. Select the desired block number by pressing the function button next to the
parameter and using the

5. Select the desired Location number by pressing the function button next to the
parameter and using the

6. Press the

T-FN menu from the MEMORY menu.
MODE parameter by pressing the function button next to it and pressing the

PRINT mode.

BLOCK

or buttons.

LOC

and buttons.

OK button to print the thickness reading for the selected Location.

6.6.2 To print all Locations in a single Block:

1. Make sure that the printer is properly connected to the serial port, turned on and on-line.

2. Select the

3. Select the
button to select

4. Select the desired block number by pressing the function button next to the
parameter and using the

5. Set the Location number to
parameter and using the

T-FN menu from the MEMORY menu.
MODE parameter by pressing the function button next to it and pressing the

PRINT mode.

BLOCK

or buttons.

ALL by pressing the function button next to the LOC

button if not already selected.

6. Press the

OK button to print the thickness reading for the selected block.

6.6.3 To print all Blocks and all Locations:

1. Make sure that the printer is properly connected to the serial port, turned on and on-line.

2. Select the

3. Select the
button to select

4. Set the Block number to ALL by pressing the function button next to the
parameter and using the

automatically set to

5. Press the

To delete any or all locations or blocks, follow the instructions above for printing except set

MODE function to DELETE instead of PRINT.

the

T-FN menu from the MEMORY menu.
MODE parameter by pressing the function button next to it and pressing the

PRINT mode.

BLOCK

button if not already selected. The location number will be

ALL

OK button to print the thickness reading for all of the blocks and locations.

Page 68

DFX-625 User’s Guide ~ Power Supply

7 Power Supply

The DFX-625 is powered by a Lithium-Ion battery pack, which is shown below. The battery
pack slides into a compartment located on the bottom of the DFX-625 and connects via a
standard smart battery connector.

7.1 Lithium-Ion Battery Pack

7.1.1 Battery Cautions

Misuse of Lithium-ion batteries may result in the following hazards: smoke, fire, or battery
rupture. Misuse can also cause other battery damage or degradation of battery performance

DANGER! Use and charge only the specified Dakota Ultrasonics battery pack with the
DFX-625. Only the Dakota Ultrasonics battery pack is tested and approved for use with the
DFX-625. Using third-party or counterfeit battery packs may cause smoke, fire, or cause the
battery to burst.

DANGER! DO NOT hammer or otherwise impact the battery. Do not use the battery if it
has been severely impacted or dropped, or if the battery has been subjected to heavy
pressure. Battery damage may not be visible on the outside of the case. Even if the surface
of the battery does not show cracks or any other damage, the cells inside the battery may
rupture or catch fire.

DANGER! NEVER use or leave battery pack in areas with temperatures above +60°C.
High temperature build-up in the battery, such as could occur near fires or stoves, inside a
sun-heated car, or by setting the battery in direct sunlight may cause the battery to rupture or
catch fire. Excessive temperatures may also degrade battery performance or shorten battery
life.

DANGER! DO NOT expose the battery to rain, snow, seawater, or any other liquids. Do
not charge or use a wet battery. If the battery gets wet, be sure to wipe it dry before using.
The battery by itself is not waterproof.

DANGER! NEVER incinerate a used battery pack since internal battery gas may cause a
rupture or explosion.

DANGER! NEVER solder the battery terminals, or modify the battery pack. This may
cause heat generation, and the battery may rupture, emit smoke or catch fire.

DANGER! Use the battery only with the DFX-625 for which it is specified. Never use a
battery with any other equipment, or for any purpose that is not specified in this instruction
manual.

DANGER! If fluid from inside the battery gets in your eyes, blindness can result. Rinse
your eyes with clean water, without rubbing them, and see a doctor immediately.

WARNING! Immediately stop using the battery if it emits an abnormal odour, heats up, or
is discolored or deformed. If any of these conditions occur, contact Dakota Ultrasonics.

Page 69

DFX-625 User’s Guide ~ Power Supply

WARNING! Immediately wash, using clean water, any part of the body that comes into

contact with fluid from inside the battery.

WARNING! NEVER put the battery in a microwave oven, high-pressure container, or in
an induction heating cooker. This could cause overheating, a fire, or cause the battery to
rupture.

• CAUTION! Always use the battery within the specified temperature range for the DFX-625
(-10°C to +55°C) and the battery itself (-20°C to +60°C). Using the battery out of its specified
temperature range will reduce the battery's performance and battery life. Please note that the
specified temperature range of the battery may exceed that of the DFX-625. In such cases,
the DFX-625 may not work properly because it is out of its operating temperature range.

• CAUTION! Shorter battery life could occur if the battery is left fully charged, completely
discharged, or in an excessive temperature environment (above +45°C) for an extended
period of time. If the battery must be left unused for a long time, it must be detached from
the DFX-625 after discharging. You may use the battery until the battery indicator shows
half-capacity, and then keep it safely in a cool dry place with the temperature between -20°C
to +25°C. If the battery pack is not going to be used for a long time it must be periodically
charged every 4 months; failure to do so will render the battery inoperable and it will need to
be returned to Dakota Ultrasonics for re-charging. If a number of spare battery packs are in
use the easiest way to main optimum conditions is to rotate the battery packs so that when
one is discharged it is swapped with a fully charged one.

7.2 Battery Charging

7.2.1 Charging Caution

DANGER! Only use the supplied AC adaptor to charge the battery. Using any other
charger may cause smoke, fire, or cause the battery to burst.

DANGER! NEVER charge the battery pack in areas with extremely high temperatures,
such as near fires or stoves, inside a sun-heated car, or in direct sunlight. In such
environments, the safety/protection circuit in the battery will activate, causing the battery to
stop charging.

WARNING! DO NOT charge or leave the battery in the battery charger beyond the
specified time for charging. If the battery is not completely charged by the specified time,
stop charging and remove the battery from the battery charger. Continuing to charge the
battery beyond the specified time limit may cause a fire, overheating, or the battery may
rupture.

WARNING! NEVER insert the battery charger into the DFX-625 or battery if it is wet or
soiled. This could corrode the battery charger terminals or damage the charger. The charger
is not waterproof.

• CAUTION! DO NOT charge the battery outside of the specified temperature range: O°C to
+40°C. Dakota Ultrasonics recommends charging the battery at +20°C. The battery may
heat up or rupture if charged out of the specified temperature range. Additionally, battery
performance or battery life may be reduced.

When fully charged, the battery pack should enable the unit to be operated for 16 hours
when the brightness is at level 1 in the VIDEO menu under UTIL, for 12½ hours with a
brightness of 10 (the default) or for 9 hours with a brightness of 20. The battery pack can be
charged while mounted to the DFX-625 by use of the connector on the front panel.
Alternately, the battery pack can be charged separate from the DFX-625 by using its own
connector shown above allowing continued operation of the DFX-625 with the use of multiple
battery packs.

Page 70

DFX-625 User’s Guide ~ Power Supply

When shipped the battery has only a nominal charge and must be fully charged before being
used for the first time.

The Dakota Ultrasonics battery charger shown below is suitable for use with main supply
from 100 to 240 volts AC. The LED on the charger illuminates to indicate power on. When
the battery is charging the LED will blink. When the battery level is full the LED glows green.
The output voltage from the charger is 24 Volts DC. The output current when charging is a
constant 3.3 Amps.

WARNING – This is a battery charger only, and cannot be connected to the DFX-625 to

power the unit.

Page 71

DFX-625 User’s Guide ~ Interface Connections

8 Interface Connections

There is a 6-pin connector on the Top end cap of the DFX-625 as shown below:

This connector is used to connect the flaw detector to a PC using a modified USB cable; this
allows information to be transferred to the computer using Dakota Ultrasonic’s program
WinDFX. For information on how to purchase WinDFX please contact Dakota Ultrasonics
using the details inside the front cover of this user’s guide. The USB connector also allows a
USB keyboard to be connected and used for data entry in the notes fields. A printer can also
be connected allowing information to be printed directly from the DFX-625. Please contact
Dakota Ultrasonics for a list for a list of supported printers.

Also located on the top end cap of the DFX-625 there are various interface connections. The
connections are shown below and described in the sections that follow:

8.1 RS232

The RS232 port on the DFX-625 allows for bi-directional communication between the
instrument and a personal computer. Various control commands are available within three
general categories; Write parameter values, Read parameter values, and Action commands.
The Write and Read parameters allow the computer to set a parameter and to read
parameters current value. The Action commands provide special functions such as
waveform and thickness logging transfer. The RS232 port is the D-shaped connector at the
bottom.

The communication handshake is as follows:

Baud rate: 9,600, 19,200, 38,400, 57,600 or 115,200

Parity: None

Data Bits: 8

Stop Bits: 1

Handshake: Hardware

The cable connections for a 9-pin RS232 port are as follows:

The cable connections for a 25-pin RS232 port are as follows:

Page 72

DFX-625 User’s Guide ~ Interface Connections

A 9-pin to 9-pin communications cable is available from Dakota Ultrasonics.

No cable is available for the 25-pin RS232 port.

8.2 Composite Video

The composite video output is for connecting the DFX-625 to a compatible video monitor or
projector. The output is either NTSC (USA/Japan) or PAL (UK/Europe), depending on the
VIDEO selection in the UTIL menu. The screen update rate is 50Hz in PAL and 60Hz in
NTSC. The composite video connector is the second connector from the top with one centre
pin.

8.3 Proportional Outputs

Proportional output 1 (P1) can be used to give the following readings: Depth 1 (Gate1),
Depth 2 (Gate2), E1–E2 (the distance between the measurements) Alarm 1 (voltage out
when the alarm is active).

Proportional output 2 (P2) can be used to give the following readings: Level 1 (Gate1) Level
2 (Gate2) L1–L2 (the difference between the two amplitudes) Alarm 2 (voltage out when the
alarm is active).

The choice of which reading to output is made using the

P_O/P feature in the UTIL menu. The proportional outputs are updated at the currently

O/P 1 and O/P 2 parameters in the

selected PRF.

The voltage of the outputs is controlled by the

UTIL menu. This allows the voltage to be varied between 0V and 10.0V. The voltage applies

CAL parameter in the P_O/P feature in the

to all proportional outputs.

It is the small upper connector with 4 pins; the top 2 pins are used for the proportional
outputs. The ground is achieved using the outer case of the connector.

8.4 Synchronisation Outputs

The DFX-625 provided two synchronisation outputs on the small 4 pin connector: S1 and S2.

S1 is synchronised with the TX pulse so that it goes high (3v3) for 50ns, at the start of the TX
signal to the analogue board.

S2 goes high (3.3V) for the duration of the acquisition period.

Page 73

DFX-625 User’s Guide ~ Features of the DFX-625

9 Features of the DFX-625

The DFX-625 is a user-friendly ultrasonic digital flaw detector and thickness gauge, which is
simple to use and provides the experienced ultrasonic operator with a full-function device
that incorporates many productivity enhancing features. All of the features of the DFX-625
are accessed through a menu system using the front panel keypad.

9.1 Functional Testing Methods

The DFX-625 supports the following ultrasonic testing methods:

• Pulse-Echo Flaw Detection

• Transmit-Receive Flaw Detection

• Time of flight measurement

• Contact or Immersion Methods

• Angle Beam (Shear Wave) Testing

• Angle Beam (Surface Wave) Testing

• Crack Diffraction Methods

• Depth of Flaw Measurement

• Single Transducer Thickness Measurement

• Dual Transducer Thickness Measurement

• Indirect Measurement of Sound Velocity in Materials

• Time measurement in microseconds

• Phase change display in un-rectified mode

• Through transmission testing

• Creep wave testing

• Pitch and catch techniques

Page 74

DFX-625 User’s Guide ~ Specifications

10 Specifications

Feature Details

Test Range 0 - 5mm (0.2in) up to 0 – 10,000 mm (400 in.) at steel

velocity. Variable in 1mm &10mm steps

Velocity 1,000 to 9,999m/s continuously variable.

Probe Zero 0 to 999.999 μs, continuously variable.

Delay Calibrated delay from 0 -10,000mm in 0.05 mm steps

at steel velocity (0-400in. in 0.002 in. steps).

Gain 0 to 110dB. Adjustable in 0.5, 1, 2, 6, 10, 14 and 20dB

steps. Direct access to gain control at all times.

Test Modes Pulse echo and transmit/receive.

Pulser -200V square wave pulser. Pulse width from 30 to

250ns duration linked to filter band. rise/fall times
<10ns into 50 ohms

P.R.F Selectable 35 to 100 Hz in 5 Hz steps, 100 to 1,000 in

50Hz steps.

Update Rate 60Hz (NTSC Mode); 50Hz (PAL Mode).

Rectification Full wave, positive or negative halfwave and unrectified

rf.

Frequency
Range

System
Linearity

6 narrow bands centred at1MHz, 2.25MHz, 5MHz and
10MHz. Broad band at 1.5 MHz to 15MHz (-6dB).

Vertical = 1% Full Screen Height (FSH). Amplifier
Accuracy ± 0.1dB. Horizontal ±0.4% Full Screen Width
(FSW).

Reject 50% linear reject. LED warning light when selected.

Units Metric (mm), inch (in) or time (μs).

Display Color
Transflective
TFT

Display area 111.4 x 83.5 mm (4.39 x 3.29 in) 320 x
240 pixels. A-Scan Area 255 x 200 pixels (315 x 200
expanded), 8 color options and variable brightness.

Gate Monitor Two fully independent gates for echo monitoring and

thickness measurement. Start and width adjustable
over full range of unit, amplitude variable from 0 to
100% FSH. Bar presentation. Positive or negative
triggering for each gate with audible and visual alarms.

Gate

Expands range to width of Gate 1.

Expansion

Gate Monitor
Delay

Selectable 0.6 seconds delay on gate 2 negative
monitor tracking.

Page 75

DFX-625 User’s Guide ~ Specifications

Feature Details

Measurement
Modes

Mode 1 Signal Monitor

Mode 2 Depth and amplitude of first signal in gate.

Mode 3 Echo-to-Echo distance measurement. (single gate)

Mode 4 Trigonometric display of beam path, surface distance

and depth of indication, curve surface correction and X­OFFSET for probe index. Half skip indication on
screen.

Mode 5 Gate to Gate distance measurement. (Independent

gates).

Mode 6 T-Min mode for holding minimum thickness reading.

Resolution 0.01mm (0.001in) for distance measurement or 1%

FSH for amplitude measurement. Large display of
measurement at top of A-Scan display. Measurement
mode selectable between peak and flank.

A-Scan
Memory

800 waveforms can be printed or transferred to a PC
using optional WinDFX software.

Panel

100 stores for retaining calibrations.

Memory

Thickness
Logging

Storage for 8,000 thickness readings configured either
by Block/Location/Number mode or pre-programmable
work sheets in sequential mode. Readings can be
exported to MS Excel using optional software.

AGC Automatic Gain Control automatically sets the signal to

a level between 10-90% FSH with tolerance between
5-20% accuracy.

DAC DAC defined by up to 10 points and digitally drawn on

screen. DAC curves meet requirements of EN 1714,
JIS and ASME standards, selectable between -2, -6, ­10, -12 and -14dB. Amplitude read out selectable
between % DAC or relative dB.

TCG Time Corrected Gain, also known as Swept Gain. 40dB

dynamic range greater than 30dB per microsecond and
up to 10 points may be used, setting all signals initially
to 80% FSH.

AWS Built in software for evaluation of defect indications in

accordance with AWS D1.1 structural weld code.

AVG/DGS Automatic calculation from probe data.

API Flaw sizing complying with API 5UE

Page 76

Feature Details

Auto-Cal Provides automatic calibration from two echoes.

Clock Sets time and date.

DFX-625 User’s Guide ~ Specifications

Reference
Waveform

This menu displays a waveform from one of the A-log
stores as a reference or fingerprint display in a color
different from the active display highlighting differences
from the reference.

Notes Alphanumeric labelling for panel and A-log allows the

user to enter Notes for storage with panel settings and
A-scans.

Display

For capturing the current A-scan image.

Freeze

Peak

For echodynamic pattern determination.

Memory

Keylock Prevents accidental alteration of parameters.

Help Key For instant operator guidance on using the Masterscan

Series.

Language

Supports 6 simultaneous languages, user selectable.

Support

Waveform
Smoothing

Gives a smooth signal envelope, simulating analogue
equipment.

Outputs Full bi-directional serial interface to transfer

parameters, thickness readings and waveform
memories. Composite video, PAL or NTSC
compatibility. Analogue proportional outputs
programmable to distance or amplitude of signal in the
gate. Transmitter sync output

USB For connection to printers, keyboards and PC.

Printers Supports any printer with PCL support including HP

Deskjet and Epson.

Power Lithium Ion battery pack 14.4V, 5.0 amp hours, gives

up to 16 hours duration from a fully charged pack.
Indication of low battery status. Recharge time 3-4 hrs.

Page 77

DFX-625 User’s Guide ~ Warranty

11 Warranty

Warranty/Defects after Delivery: Immediately upon receipt of the goods the buyer is required
to check the goods carefully and thoroughly. In order to benefit from the guarantee, any
defect in the product should be immediately reported in writing to Dakota Ultrasonics.
Dakota Ultrasonics will make good by repair or by the supply of a replacement or by
equivalent adjustment of the price at our sole option, any defects which under proper use
appear in the goods within the period of twenty-four (24) calendar months after the goods
have been delivered and which arise solely from faulty design, material or workmanship,
provided that the goods are carefully packed and promptly returned by you, free of charge, to
the Dakota Ultrasonics works unless otherwise arranged. Said goods should be covered
while in transit to us and must be accompanied by a written statement detailing the precise
nature of the fault and the operating conditions under which the fault occurred. The repaired
goods will be returned by Dakota Ultrasonics free of charge.

Save as in this Clause herein before expressed Dakota Ultrasonics shall not be under any
liability in respect of defects in goods delivered or for any injury damage or loss resulting
from such defects and our liability under this Clause shall be in lieu of any warranty or
condition implied by law as to the quality, fitness or merchantability for any particular purpose
of such goods.

Page 78

12 Index

A

A-Cal · 10, 15, 37, 44, 62, 63
A-CAL Menu · 15
Adding NOTES to PANEL and A-LOG sets · 30, 33, 58
Adjustment · 55
AGC · 13, 26, 27, 76
AGC (Automatic Gain Control) · 26
A-Log · 13, 27, 30, 31, 33, 34, 35, 39, 57, 58, 59, 60, 63

A-Scan Storage · 30, 39, 57, 60

Memory Menu · 30
American Welding Society · 23, 46
Amplifier · 7, 14, 22, 37, 42, 61, 75
Amplifier Menu · 14
angle · 7, 18, 19, 36, 39, 44, 45, 50, 51, 52, 59
Angle · 56, 74
Angle Beam · 74
API · 13, 17, 24, 48, 76

Menu · 24
A-Scan · 1, 7, 11, 25, 27, 29, 30, 31, 39, 57, 58, 60, 75,

76
A-Scan Storage · 30, 39, 57, 60
Attenuation · 20, 21, 23, 36, 40, 42, 46, 50, 52, 61, 64
AVG · 1, 13, 17, 21, 27, 50, 51, 52, 53, 54, 55, 56, 76
AWS · 13, 17, 23, 27, 46, 47, 56, 76
AWS Menu · 23, 46

DFX-625 User’s Guide ~ Warranty

Centre Frequency · 14
Certification · 2
Charge · 71, 78
Charger · 8, 71
Clearing the Memory · 11
Click · 25
Clock · 13, 28, 77
CLOCK Menu · 28
Composite Video · 25, 73, 77
Concave · 19
Connector · 7, 15, 70, 72, 73
Contact · 5, 36, 37, 61, 69, 72, 74
Contents · i
Contour · 56, 59
Contour & Peak Echo Dynamics · 59
Controls · 1, 6, 12, 25, 27
Convex · 19
Corrosion · 61
Couplant · 4, 32, 66
Coupling · 4, 21, 40, 42, 52, 59
Crack Diffraction · 74
Critical Operating Factors · 2
CSC · 13, 19
CSC (Curved Surface Correction) · 13, 19
Cursor · 6, 20, 22, 23, 34, 35, 40, 42, 46, 58
Curve · 20, 21, 22, 40, 41, 42, 43, 50, 54, 55, 56, 76

D

B

Backwall · 37, 51, 66
Basic Flaw Testing · 36
Basic Thickness Gauging · 61, 65, 66
Battery · 1, 8, 11, 25, 69, 70, 71, 77
Battery Charging · 70
Battery Pack · 69
Baud Rate · 26, 72
Beam · 2, 4, 7, 18, 36, 39, 40, 42, 44, 45, 46, 50, 59, 61,

74, 76
Beam Path Distance · 18, 44
Blank · 31, 32, 35, 67
Block · 3, 4, 9, 10, 15, 21, 31, 32, 36, 37, 44, 50, 52, 53,

61, 62, 68, 76
BNC · 7
Broad Band · 75
Button · 56

C

CAL · 6, 9, 10, 13, 14, 15, 24, 27, 37, 38, 44, 48, 56, 61,

62, 63, 64, 73

Menu · 14
Calibration · 1, 3, 4, 7, 9, 10, 11, 13, 14, 15, 21, 24, 27,

29, 30, 32, 33, 35, 36, 37, 38, 40, 42, 44, 52, 53, 54,

57, 61, 62, 63, 66, 77
Calibration Block · 52, 53
Calibration Menu · 14
Calibration of the Sound Velocity · 3
Calibration Setups · 11, 29, 33

DAC · 1, 13, 17, 20, 21, 40, 41, 46, 50, 56, 76
Data Bits · 72
dB · 7, 20, 21, 23, 41, 46, 47, 51, 52, 56, 76
Default · 11, 25, 26, 65, 70
Delay · 6, 14, 15, 21, 51, 52, 61, 62, 64, 75
Delete a panel set: · 33
Delete a Stored A-Scan · 58
Depth Distance · 18, 44, 46
Depth of Flaw · 74
Detailed Menu Description · 1, 12
Detect · 56
DGS · 1, 21, 50, 51, 52, 53, 54, 55, 56, 76
DGS/AVG · 1, 21, 50, 51, 52, 53, 54, 55, 56
Diffraction · 59, 74
Disclaimer of Liability · 5
Disclaimers and Notices · 1, 2
Discontinuity · 4, 37, 44, 45, 57, 59
Dual Element · 50, 61, 62
Dual Probe · 56
Dynamic · 40, 43, 60, 76

E

Echo Dynamic · 7, 49, 59
Edit Notes · 34, 58

Summary · 34
Effects of Temperature on Calibration · 4
Electromagnetic Compatibility · 5
Envelope · 7, 25, 59, 60, 77
Evaluation of Pipe Imperfections using API 5UE · 24, 48

Page 79

F

Factory Default · 11
Far Field · 50
Far Surface · 36
Flank · 76
Flaw Detection · 4, 9, 74
Flaw Detection Calibration · 4
Flaw Detector · 2, 3, 59, 72, 74
Flaw Testing · 1, 14, 36, 37
Flaw Testing Calibration · 14, 37
Focus · 50
Freeze · 7, 17, 26, 57, 77
FREEZE/PEAK · 7
Frequency · 50, 51, 75
Front Panel Controls · 1, 6, 12
Front Surface · 4, 36
Function · 1, 11, 17, 19, 29, 30, 33, 34, 35, 40, 42, 46, 50,

55, 63, 65, 66, 68, 74

Functional Testing Methods · 74

MEAS · 6, 9, 10, 13, 17, 19, 20, 23, 24, 37, 38, 40, 42,

44, 45, 46, 48, 51, 62, 63
MEAS Menu · 17
Measurement · 1, 13, 15, 17, 20, 22, 23, 24, 25, 37, 38,

41, 44, 46, 48, 49, 50, 54, 55, 56, 62, 74, 75, 76
Measurement Menu · 13, 17
Memory · 1, 6, 11, 13, 29, 30, 31, 33, 57, 58, 65, 66, 68,

76, 77
MEMORY · 6, 13, 29, 33, 57, 58, 65, 66, 68
Menu Tree · 12
Metric · 9, 10, 75
Microseconds · 14, 74
MISC · 13, 25
MISC Menu · 25
Mode · 2, 6, 7, 9, 10, 14, 15, 17, 18, 21, 22, 23, 25, 26,

27, 30, 31, 32, 33, 36, 39, 40, 41, 42, 43, 44, 45, 46,

47, 48, 49, 56, 58, 59, 60, 62, 65, 66, 68, 74, 75, 76
Mode Conversion · 2
Multiple Echo · 62

N

G

Gain · 7, 22, 26, 37, 40, 41, 42, 46, 50, 51, 54, 55, 56, 62,

64, 75, 76

Gate · 15, 16, 17, 18, 20, 22, 24, 25, 26, 27, 37, 38, 40,

46, 48, 54, 55, 56, 62, 63, 75, 76, 77
Gate 1 · 9, 10, 13, 15, 37, 38, 48, 62, 63
Gate 2 · 13, 15, 37, 38
Gates · 15, 17, 18, 75, 76
General Warnings · 2
Ghosting · 14

H

Handshake · 72
Hardcopy · 57
Help · 7, 33, 77
HUD · 9, 10, 17, 32, 62, 66

I

Immersion · 74
Included Angle · 61
Interface Connections · 1, 72

L

LEMO · 7
Level · 14, 15, 17, 20, 23, 25, 26, 31, 46, 54, 65, 70, 71,

73, 76
Lithium-Ion Battery Pack · 69
Loc · 31, 32, 65, 66, 68
Location · 29, 30, 31, 32, 33, 34, 44, 57, 58, 65, 66, 67,

68, 76
Longitudinal · 61

M

Main Menu · 13
Main Menu Selection · 13

Near Field · 4, 21, 50, 51
Notes · 27, 29, 30, 31, 32, 33, 34, 35, 58, 66, 67, 72, 77
Notes Window · 34
NTSC · 25, 73, 75, 77

O

O/P · 13, 27, 73
Operator Training · 2
Orientation · 4, 36
Outputs · 27, 73, 77

P

P_O/P (Proportional Output) · 13, 27, 73
P_O/P Proportional Output Control Menu · 27
PAL · 11, 25, 73, 75, 77
Panel · 1, 6, 11, 12, 13, 29, 30, 32, 33, 34, 35, 58, 63, 66,

70, 74, 76, 77

Parameter · 6, 7, 9, 10, 13, 26, 33, 37, 40, 41, 42, 43, 44,

45, 53, 57, 58, 62, 68, 72, 73
Parity · 72
Peak · 49, 59, 77
Peak Echo Dynamics · 59
Pipe · 24, 48
Pitting · 32, 61, 66
Planar · 36
Point · 7, 18, 19, 20, 22, 40, 42, 44, 61, 62, 64, 66
Power Supply · 1, 8, 69
PRF · 9, 10, 14, 26, 27, 73
Print · 6, 13, 25, 27, 32, 33, 65, 66, 68
Print a single Location: · 68
Print all Blocks and all Locations: · 68
Print all Locations in a single Block: · 68
Print Menu · 13, 27, 32, 33, 68
PRINT Menu · 27
Printing · 27, 32, 39, 57, 62, 66, 68
Probe · 2, 4, 19, 21, 44, 46, 50, 51, 52, 53, 54, 56, 75, 76
PROBE Menu · 19
Probe Zero · 21, 52, 56, 75
Proportional Outputs · 73
Pulse · 2, 14, 15, 73, 74, 75

Page 80

Pulse Repetition Frequency · 14
Pulse-Echo · 74

Q

Qualification · 2
Quick Start · 1, 6

R

Range · 4, 9, 10, 14, 15, 26, 37, 40, 42, 43, 44, 50, 53, 55,

56, 59, 61, 62, 63, 64, 75, 76
Recall · 6, 11, 29, 30, 31, 33, 57, 58, 66
Recall a panel set: · 33
Recall an A-Scan · 58
Recall an A-Scan as a Reference Waveform: · 58
Receiver · 7
REF · 13, 21, 23, 31, 41, 46, 52, 53, 55, 56, 58
REF, Reference Waveform Comparisons · 58
REF/GAIN · 13, 56
Reference · 1, 3, 4, 7, 15, 20, 21, 22, 23, 24, 29, 31, 36,

37, 40, 41, 42, 46, 48, 50, 51, 52, 53, 54, 56, 57, 58,

59, 61, 63, 64, 77
Reference Block · 3, 36, 40, 42, 50, 51, 52, 54, 57, 61
Reject · 14, 56, 62, 75
Reset · 11, 17, 26, 62
Reset to factory defaults: · 11
Resolution · 36, 37, 76
RS232 · 32, 72, 73

S

Sensitivity · 9, 21, 36, 37, 50, 51, 54, 56
Shear · 74
Shear Wave · 74
Single Probe · 56
Size · 4, 6, 21, 22, 24, 36, 40, 42, 50, 51, 53, 56, 66
Skips · 18, 44
Socket · 7, 8, 35
Sound Field · 21, 50, 52
Sound Velocity · 3, 4, 15, 36, 61, 74
Specific Warnings · 2
Specifications · 2, 75
Start · 1, 6, 11, 15, 16, 17, 24, 62, 63, 73, 75
State · 6, 15
Stop Bits · 72
Storage · 11, 29, 30, 31, 32, 33, 39, 57, 60, 62, 65, 66, 76
Storage & Recall of Calibration Setups · 11, 29, 33
Store · 6, 11, 29, 30, 31, 32, 33, 34, 35, 57, 58, 65, 66
Store a panel set · 33
Store An A-Scan · 57
Surface · 4, 18, 19, 21, 26, 36, 37, 44, 46, 50, 51, 52, 59,

74, 76
Surface Wave · 36, 74
Synchronisation Outputs · 73

T

TCG · 1, 13, 17, 21, 22, 40, 42, 43, 46, 50, 56, 64, 76
Temperature · 4, 25
Temperature Variations · 4

DFX-625 User’s Guide ~ Warranty

Test Blocks · 4, 46, 61, 63
Testing Limitations · 2
T-FN · 13, 31, 32, 62, 65, 66, 68
Theory · 50
Thickness Gauge · 2, 74
Thickness Gauging · 1, 10, 61
Threshold · 15, 17, 20, 40, 64
Time Corrected Gain · 22, 40, 42, 64, 76
Time of Flight · 3, 48, 74
Time-of-Flight · 63
T-Log

Menu Numeric Mode · 31
Menu Sequential Mode · 32
Thickness Storage (Numeric) · 65

Thickness Storage (Sequential & Download) · 32, 66
T-LOG · 13, 31, 32, 62, 65, 66, 68
T-Min · 76
Training · 2
Transducer (Probe) Zero Procedure · 4
Transducer Condition · 4
Transmit-Receive · 74
Transmitter · 7, 77
Trigger · 40
Trigonometric · 76
Twin · 7
TX · 13, 56, 73
Typographical Conventions · 1

U

Ultrasonic · 1, 2, 3, 4, 5, 12, 24, 44, 48, 50, 61, 63, 64, 74
Ultrasonic Testing · 1, 2, 5, 12, 63, 74
Unrectified · 75
USB · 7, 27, 34, 35, 68, 72, 77
Use of Couplant · 4
Using the Front Panel Keypad · 35
Using the Optional Keyboard · 35
UTIL · 6, 7, 9, 10, 13, 14, 25, 70, 73
Utilities · 13

V

Valid · 27, 50, 57
VEL · 9, 10, 14
Velocity · 2, 3, 9, 10, 14, 21, 25, 37, 44, 50, 52, 53, 61,

63, 64, 74, 75
Velocity of Sound · 2, 14, 37, 44, 63, 64
Video · 11, 13, 25, 59, 70, 73
VIDEO Menu · 25

W

Warranty · 78
Wave · 2, 14, 48, 52, 56, 74, 75
Wavelength · 36, 50, 53, 61
Wedge · 52
Weld · 18, 23, 36, 39, 44, 46, 59, 76
Weld Inspection · 18, 23, 36, 39, 44, 46, 59
Weld Inspection Using the AWS Menu · 23, 46
Weld Inspection Using Trigonometry Mode · 36, 39, 44,

46
Width · 2, 14, 15, 17, 50, 56, 59, 63, 75

Page 81

Z

Zero · 4, 6, 14, 15, 44, 52, 53, 56, 61, 63, 64, 75

Page 82