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OPERATION MANUAL

DAKOTA ULTRASONICS

DDFFXX--77

Ultrasonic Flaw Detector

(Manual 2 of 2)

P/N P-220-0002 Rev 1.0, June 2011

CHAPTER ONE INTRODUCTION ...................................................................... 1

CHAPTER TWO QUICK START GUIDE ............................................................ 3

CHAPTER THREE KEYBOARD, MENU, & CONNECTOR REFERENCE ......... 7

CHAPTER FOUR SETTING UP FOR MEASUREMENT .................................. 23

CHAPTER FIVE CALIBRATION ....................................................................... 35

CHAPTER SIX TRIGONOMETRY MODE ........................................................ 50

CHAPTER SEVEN AWS – WELD INSPECTION ............................................. 55

CHAPTER EIGHT DISTANCE AMPLITUDE CORRECTION (DAC) ................ 60

CHAPTER NINE TIME CORRECTED GAIN (TCG) ......................................... 66

CHAPTER TEN ADDITIONAL FEATURES OF THE DFX-7 ............................. 71

CHAPTER ELEVEN DATA STORAGE – SETUP, EDIT, & VIEW FILES ......... 95

CHAPTER TWELVE SETUPS – CREATE, STORE, EDIT, & RECALL ......... 120

CHAPTER THIRTEEN USING THE UTILITY SOFTWARE ............................ 130

APPENDIX A - VELOCITY TABLE ................................................................. 132

APPENDIX B - SETUP LIBRARY ................................................................... 134

CHAPTER ONE INTRODUCTION

The Dakota Ultrasonics model DFX-7 is both, an ultrasonic flaw detector, as well as an ultrasonic A/B Scan thickness scope, in a single unit. It’s a combination of both our CMX DL+, as well as our new DFX-7 flaw detector series. Why is this advantageous? Thickness gauge are specifically setup to very accurately measure thickness, locate pits, flaws and blind surface corrosion. All the linearity tables, correction curves for various types of longitudinal transducers and features are built with dimensional thickness as its primary focus. Flaw detectors are designed to detect, size, position, and differentiate between flaw types in various materials and welded joints. A flaw detector must be fast, in terms of its sample and screen refresh rate, as inspectors are generally scanning the surface of a part or test specimen at a relatively high speed, rather than looking for the thickness at a specific point or location. While flaw detectors can also measure material thickness with reasonable accuracy, they are not designed with precision thickness as their primary focus.

The DFX-7 combines the two types of gauges into one powerful and full featured instrument, that’s equipped with a number of comprehensive toolkits to provide the user the arsenal necessary to address a number of common field applications. In and effort to avoid complexity issues and differential between gauges types, this manual focuses only on the flaw detector portion of the DFX-7.

Dakota Ultrasonics maintains a customer support resource in order to assist users with questions or difficulties not covered in this manual. Customer support may be reached at any of the following:

Dakota Ultrasonics Corporation 1500 Green Hills Road, #107 Scotts Valley, CA 95066 USA Telephone: (831) 431-9722 Facsimile: (831) 431-9723 www.dakotaultrasonics.com

1.1 General Disclaimer

The manual should be read and understood prior to using the DFX-7. This operating manual provides the user with all the general information necessary to use and operate the features of the DFX-7. However, this manual is not a certified NDT training course, nor is it intended to be one. Ultrasonic training for sound wave theory, flaw detection and interpretation of defects is highly recommended, and will be required by most companies and contract services. Contact the local NDT society in your area to inquire about training available in your locality.

1.2 Electrical Warning

The DFX-7 contains a high voltage pulser. It’s recommended that the gauge be powered off prior to connecting or disconnecting your transducer, to avoid damaging the DFX-7.

CHAPTER TWO QUICK START GUIDE

This section will cover a basic quick start guide to initially get up and running with the DFX-7 for demonstration purposes only. However, in order to use the gauge and features for actual applications, a thorough review of this manual is recommended.

2.1 Gauge Type

Power up the DFX-7, by pressing the on/off key located in the bottom right corner of the keypad. During initial boot up, a flash screen and lights will be displayed, followed by a GAUGE TYPE selection screen. Since this manual will focus on the flaw detector portion of the DFX-7, use the UP/DOWN arrow keys to select “flaw detector”, followed by pressing the OK key start the DFX-7 in flaw mode. If this is the first time the gauge has been used, a general startup configuration will automatically be loaded and the DFX-7 is ready for general inspections. If this is not the first time the gauge has been used, and the user would like to reload the basic default setup parameters, refer to section 12.5 for further info.

Note: The default setup should only be considered as a basic setup. Proper calibration and parameter settings should be done prior to an actual inspection.

2.2 Basic Flaw Setup Reference

The following table lists all the settings for the basic flaw setup:

PRB CAL DISP TUNE GT1

Type: Single Matl: Steel 1020 View: +Rect Filters: Wide Alarm: On

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Pulse: Thin Matl 1pt: Uncal Delay: 0.000 Gain: 65 Gate1: 0.484 Max PRF: 66 Matl 2pt: Uncal Range: 5.011 Detect Mode: Z-Cross Thresh1: 40% Damping: 600 Velocity: .2320 Units: inches Width1: INF Pulser Volt: 200 Zero: 0.0 Brightness: 15 Detect: Above View: Green 1 Polarity: Pos Dim: Off Rect Wave: Filled Detect Mark: None

Note: The following features are set to off: GT2, TRIG, AWS, TCG, DAC, DGS.

2.3 Top & Submenu Reference

The following table is a quick menu reference guide. The DFX-7 has 15 top level menu titles, and multiple submenu items as illustrated below. Refer to Chapter Three for additional definitions and information on the keypad and menu items.

Start >>

PRB CAL DISP TUNE GT1 GT2 TRIG AWS

TYPE MAT VIEW FILTERS ALARM ALARM TRIG AWS

PULSE MATL 1PT DELAY MAX PRF DETECT DETECT THICKNESS SET REF GAIN

DAMPING MATL 2PT RANGE GAIN GATE1 GATE2 ANGLE % SCRN

HEIGHT

PULSER

VOLTAGE

ZERO BRIGHTNESS THRESHOLD1 THRESHOLD2

COLORS POLARITY1 POLARITY1

DIM

RECT WAVE

DETECT MARK

VELOCITY UNITS DETECT MODE GATE1 WIDTH GATE2 WIDTH X-OFFSET

>> End

TCG DAC DGS SET DATA UTIL XFER

TCG DAC DGS OPEN NEW AUTO FIND BACKUP

SETUPS

DRAW DRAW PROBE

CONFIG

CURVE MEAS TRANS LOSS DELETE ONE OPEN BACKUP DATA

SAVE EDIT GAUGE RESTORE

SETUPS

FILE

DFX-7 Ultrasonic Flaw Detector

% SCRN HEIGHT

TRIGGER MATERIAL

DPOLARITY TB VELOCITY DELETE ALL

TB TYPE

TB SIZE

SIGNAL

CURVE REFLECT

LOSS

LANGUAGE DELETE ONE

LOSS

DEFAULT

SETUP

CLOSE RESTORE

DATA

ABOUT

FILE

DATA

2.4 Loading the Default Setup

If the DFX-7 has previously been used, the basic default settings can be reloaded at any time, as outlined below:

Load Default Setup

The following section assumes the gauge is powered up, the flaw detector option selected, and the main measurement screen is being displayed.

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the SET menu is highlighted and displaying the submenu items.

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2) Use the UP and DOWN arrow keys to scroll through the sub menu items until DEFAULT SETUP is highlighted.

3) Press the ENTER key to display the confirmation screen.

4) Press the OK key to load the default setup and return to the measurement screen.

CHAPTER THREE KEYBOARD, MENU, & CONNECTOR REFERENCE

3.1 Menu Key (Operation & Sub Menus)

The Menu key activates the primary menu structure containing 15 menu tab groups. These tab groups then contain sub menu items, or functions. The sub menu items have been organized in the tab groups according to how closely they are related to the individual tab group names. Let’s first get familiar with how to move around in these tabs before continuing on to the sub menu functions. This procedure is outlined below:

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Activating and Navigation of the Menu Items

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left until the desired tab group is highlighted and displaying the submenu items. The tab groups are illustrated above (A).

Now that you’re familiar with activating and moving amongst the tab groups,

let’s have a look at how to move around in the sub menu items as follows:

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until the desired function is highlighted. The sub menu items are illustrated in the diagram above (B).

3) Depending on which function is highlighted, use the LEFT, RIGHT, and Enter keys to scroll the options or activate the Digit Edit and List Box options.

The sections to follow will provide the user with an explanation of the sub menu functions:

DFX-7 Ultrasonic Flaw Detector

3.2 Probe – Menu

TYPE: Dual.

PULSE: The DFX-7 has an adjustable pulse width for both high penetration and

resolution applications. The pulse width refers to the duration of time the pulser is on. The options are Spike, Thin, and Wide. Refer to page 86 for a further explanation.

MAX PRF: This feature controls the pulse repetition frequency of the DFX-7. The maximum frequency is 333 Hz. However, the DFX-7 will automatically adjust the PRF according to what the current delay and range settings have been adjusted to. Larger the range, the slower the repetition frequency will automatically be set for.

DAMPING: The ability to control the amplifiers output impedance to match the impedance of the transducer, and optimize overall transducer performance. Adjustable at: 50, 100, 300, 600, 1500 ohms. Refer to page 90 for further info.

PULSER VOLT: Adjustable pulser voltage: 100, 150, and 200 volt. Refer to page 87 for a further explanation.

Enables the user to select the type of transducer being used, either Single or

3.3 CAL – Menu

Select the material velocity from a chart of basic material types when a known

MAT: sample thickness, or material velocity cannot be obtained.

MATL 1PT: Performs a single point calibration. Used in conjunction with the MATL

2PT option for the calibration process. Refer to page 35 for further info. MATL 2PT: Performs a two-point calibration. This option allows the user to

automatically calculate the velocity by entering a second known sample thickness. Refer to page 35 for further info.

VELOCITY: Function to calibrate the DFX-7 by setting the velocity to a known material velocity. Refer to page 71 for further info.

ZERO PROBE: Used to zero the transducer and calibrate the screen. The DFX-7 is zeroed in much the same way that a mechanical micrometer is zeroed. If the DFX-7 is not zeroed correctly, all of the measurements made using the DFX-7 may be in error by some fixed value. Refer to the section on page 35, for further info.

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3.4 DISP (display) – Menu

VIEW: Selectable RF, +RECT, -RECT, RECTFW views. Refer to page 23 for further

info.

DELAY:

views. Refer to page 24 for further info.

RANGE:

viewable measurement area. It functions a lot like a zoom on a camera. Refer to page 24 for further info.

UNITS: Toggle between English or Metric units. The readout will change from inches to millimeters.

BRIGHTNESS: AMOLED high speed color display. An arbitrary scale of 1-20 has been implemented, with the brightest setting at 20. Refer to page 76 for further info.

SCREEN UPDATE: Toggles how fast the display will redraw. Options are 60Hz or 120Hz. The 60Hz option conserves battery life. Refer to page 88 for further info.

COLORS: Provides the user with a variety of different color schemes to select from. There are two schemes for each main color option. Refer to page 77 for further info.

DIM: Allows the user to conserve battery life by diming the display after idle for a specific amount of time – OFF, 30, 60, 90, 120 seconds. Once dimmed, a single press of any key will restore the screen brightness. Refer to page 79 for further info.

RECT WAVE: Provides the user an outlined or filled view option when the display setting is in RECT (rectified) wave mode only. Refer to page 80 for further info.

DETECT MARK:

waveform: Line, Box, Dots, None. Offers the user a graphics preference on how they prefer to view the detection on the waveform.

Provides the user the ability to change the start position of the A-SCAN

Provides the user the ability to change the overall range/depth of the

Selectable graphics option for the point of detection on the

3.5 TUNE – Menu

FILTERS:

19 MHz (-3dB). The DFX-7+ is additionally equipped with selectable narrow band filters at; 2, 5 & 10 MHz. Refer to page 91 for further info.

GAIN:

used to increase/decrease the strength or amplitude of the signal. This might easily

The DFX-7 is a wide band flaw detector with a frequency range of 1.8 to

The DFX-7 has a 0-110dB gain range with 2dB resolution. This feature is

DFX-7 Ultrasonic Flaw Detector

be considered as similar to turning the volume up or down on a stereo receiver. Refer to page 27 for further info.

DETECT MODE: The DFX-7 is equipped with optional detection modes; PEAK, FLANK, or Z-CROSS (zero crossing). This options allows the user to decide where the detection is acquired on the waveform echo. Refer to page 84 for further info.

3.6 GT1 – Menu

ALARM: Toggles the alarm function of gate 1; on, off, audible. The audible feature

sounds a beeper when the waveform breaks the threshold level, either above or below, depending on the current DETECT setting. Refer to page 30 for further info.

DETECT: Enables the user to set the alarm detection to occur either above or below the gates threshold level. Refer to page 30 for further info.

GATE1: Gates allow the user to view a specific inspection/measurement range, or specific regions of the waveform, while ignoring others. In order to detect on a waveform echo, and display the amplitude as a percentage of full screen height, the echo must be inside the boundaries of the gate settings. The GATE1 feature adjusts where the gate begins, according to the depth/thickness. Refer to page 30 for further info.

GATE1 WIDTH: This feature allows the user to set the overall width of the gate, in terms of distance, from the GATE1 setting. Refer to page 30 for further info.

THRESHOLD1: Enables the user to set the sensitivity level of Gate1 to a calibrated screen height percentage. The threshold level will act as a starting point for the alarm trigger, and is directly associated with the DETECT setting outlined above. Refer to page 30 for further info.

POLARITY:

polarity, or stroke, of the half or full wave cycle. It should be noted that if the VIEW is set to positive, and the gate negative, the DFX-7 will not display an amplitude percentage of full screen height. Refer to page 30 for further info.

The gates can be set to detect on either the positive or negative

3.7 GT2 – Menu

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ALARM: Toggles the alarm function of gate 2; on, off, audible. The audible feature sounds a beeper when the waveform breaks the threshold level, either above or below, depending on the current DETECT setting. Refer to page 30 for further info.

DETECT: Enables the user to set the alarm detection to occur either above or below the gates threshold level. Refer to page 30 for further info.

GATE2: Gates allow the user to view a specific inspection/measurement range, or specific regions of the waveform, while ignoring others. In order to detect on a waveform echo, and display the amplitude as a percentage of full screen height, the echo must be inside the boundaries of the gate settings. The GATE2 feature adjusts where the gate begins, according to the depth/thickness. Refer to page 30 for further info.

GATE2 WIDTH: This feature allows the user to set the overall width of the gate, in terms of distance, from the GATE2 setting. Refer to page 30 for further info.

THRESHOLD2: Enables the user to set the sensitivity level of Gate2 to a calibrated screen height percentage. The threshold level will act as a starting point for the alarm trigger, and is directly associated with the DETECT setting outlined above. Refer to page 30 for further info.

POLARITY: The gates can be set to detect on either the positive or negative polarity, or stroke, of the half or full wave cycle. It should be noted that if the VIEW is set to positive, and the gate negative, the DFX-7 will not display an amplitude percentage of full screen height. Refer to page 30 for further info.

3.8 TRIG – Menu

TRIG: This feature toggles trigonometry feature on/off. This feature is used with

angle beam transducers for the inspection of welds, to calculate three measurements: Beam path distance (Ì), Surface distance (Æ), and Depth (È) from the index point of the transducer. Refer to page 50 for further info.

THICKNESS: Used to set the thickness of the test material. The thickness will be used to determine which skip/leg the DFX-7 is detecting on. Refer to page 50 for further info.

ANGLE:

Refer to page 50 for further info.

X-OFFSET:

function, as is a physical measurement from the index point of the probe to the front of the wedge/can/shoe/case. Refer to page 50 for further info.

CSC OD: Curved surface correction to compensate for changing sound path distance and angle. This feature is used in conjunction with ‘thickness’ in order to calculate a correction factor. Refer to page 50 for further info.

Used to set the angle of the transducer, and used in the calculations above.

This feature is used to calculate the surface distance in the trigonometry

DFX-7 Ultrasonic Flaw Detector

3.9 AWS – Menu

AWS:

according to American Welding Society’s structural welding code D1.1-94, to calculate the Indication Rating (IR). Refer to page 55 for further info.

SET REF GAIN:

percentage of full screen height (FSH). This value will typically be set somewhere between 20%–90%. Refer to page 55 for further info.

ANGLE: This is used to set the angle of the transducer used for the calculations above. Refer to page Error! Bookmark not defined. for further info.

X-OFFSET: This feature is used to calculate the surface distance in the trigonometry function, as is a physical measurement for the index point of the probe to the front of the wedge/can/shoe/case. Refer to page 55 for further info.

This feature toggles the AWS feature on/off. Used in the analysis of welds

The gain (in dB) required to set the indication level to a specific

3.10 TCG – Menu

TCG: This feature toggles the TCG feature on/off. The Time Corrected Gain (TCG)

feature displays reflectors of equal size at equal A-Scan amplitudes, regardless of the reflector’s depth in the test material. Refer to page 66 for further info.

DRAW: Toggles the DRAW mode on/off, and used to draw the TCG curve. Refer to page 66 for further info.

CURVE:

screen. Refer to page 66 for further info. % SCRN HEIGHT: This feature enables the user to set the reference level of the

TCG as a percentage of full screen height (FSH). Refer to page 66 for further info.

Toggles the TCG correction curve on/off, and the curve is displayed on the

3.11 DAC – Menu

DAC: Toggles the DAC feature on/off/audible. A Distance Amplitude Correction

(DAC) curve is used to configure a variable threshold for the gate, using the same size reflector at different distances. Refer to page 60 for further info.

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DRAW: Toggles the DRAW mode on/off/audible, and used to draw the DAC curve. Note: TCG curve cannot be drawn in RF view. Refer to page 60 for further info.

MEAS: Toggles the units displayed as a relationship of either the signal amplitude and DAC curve, or just the signal according to screen height. The units are as: %FSH, %DAC, and dB. Refer to page 60 for further info.

CURVE: Selectable signal or multi DAC curve options. The displayed curve options are: DAC, -2dB, -6dB, -10dB, (-6dB/-12dB), (-6dB/-14dB). Once the DAC curve has been generated, these options can be toggled at any time. Refer to page 60 for further info.

TRIGGER: Used to set the alarm threshold for the DAC curve. The options are; at DAC, -2dB, -6dB, -10dB, -12dB, -14dB, or using an independent gate. The list of trigger options will change according to which CURVE option has been selected. Refer to page 60 for further info.

DPOLARITY: Used to select the polarity of the DAC curves generated, either positive or negative. Refer to page 60 for further info.

3.12 DGS – Menu

DGS: Coming Soon.

3.13 SETUP – Menu

OPEN:

These setups can be recalled and used at any time. Refer to page 120 for further info.

SAVE:

modified or created by the user. Refer to page 122 for further info.

DELETE:

in memory. Refer to page 125 for further info.

DEFAULT SETUP:

setups in the DFX-7 have been corrupted and a computer is not accessible. Refer to page 127 for further info.

Displays a list of factory and user defined setups currently stored in memory.

Provides the user with the ability to save a custom setup that has been

Provides the user with the ability to delete specific setups previously save

Loads a basic default setup. Use only as a last resort when the

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LANGUAGE: Provides the user the ability to select different languages for the DFX-

7. Refer to page 129 for further info.

3.14 DATA – Menu

NEW: Allows the user the ability to create a new alpha numeric grid, or sequential

log file with auto identifiers. It is equipped with custom parameters, rows, and columns depending on the user’s application reporting requirements. Refer to page 96 for further info.

EDIT: Gives the user the ability to change parameters of grid or sequential file previously saved. Note: Pre-defined coordinates cannot be changed once they have been created. Refer to page 114 for further info.

OPEN: This function provides the user with the ability to recall grids or sequential log files that currently exist in memory, from a list of grids. Refer to page 116 for further info.

CLOSE: Provides the user the ability to close a currently opened grid or sequential log file. Refer to page 118 for further info.

DELETE ONE FILE: This function provides the user with the ability to delete one individual grid or sequential log file from a list of multiple grids/files previously saved in memory. Refer to page 111 for further info.

DELETE ALL DATA: This function provides the user with the ability to delete all files currently stored in memory. Refer to page 112 for further info.

3.15 UTIL (utilities) – Menu

AUTO FIND:

the viewable display area, and automatically sets up the gauges scope settings. Refer to page 71 for further info.

GAUGE:

detector, or a thickness gauge. Refer to page 3 for further info.

Automatically locates the detection point if the measurement is out of

Gives the user the ability toggle the DFX-7 gauge type to either a flaw

3.16 XFER (transfer) – Menu

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BACKUP SETUPS: Enables the user the ability to backup the setups currently stored in the DFX-7 to a PC via RS232 port. USB adaptor included. Refer the help section of the DFX-7 DakView software for a complete electronic manual.

RESTORE SETUPS: saved on a PC to an DFX-7 via RS232 port. Refer the help section of the DFX-7 DakView software for a complete electronic manual.

BACKUP DATA:

currently stored in the DFX-7 to a PC via RS232 port. Refer the help section of the

DFX-7 DakView software for a complete electronic manual. RESTORE DATA: Enables the user the ability to restore grids or sequential log files

currently saved on a PC to an DFX-7 via RS232 port. Refer the help section of the

DFX-7 DakView software for a complete electronic manual. ABOUT: Provides the user with Dakota Ultrasonics contact information and the

DFX-7 software version. Refer to the Dakota Ultrasonics web site for information on the latest firmware versions available for download.

Enables the user the ability to restore the setups currently

Enables the user the ability to backup grids or sequential log files

3.17 CLR (clear) Key

The primary functions of the CLR key, is to clear a measurement from a grid or sequential log files cell location or set obstruct, backspace in an Alpha Edit Box, or clear a DAC reference point used to generate a curve. Use this key to clear saved measurement & waveform.

3.18 MEAS (measurement mode) Key

The MEAS key puts the DFX-7 into it’s primary mode of operation. In this mode, the user has a complete view of the LCD. When pressed multiple times, navigates the hot menu items.

3.19 OK Key

The primary function of the OK key is confirmation of a change or selection. The OK key also toggles the Hot Menu area, while in measurement mode, to a large digits display area. If the DFX-7 is displaying a grid log, the OK key toggles an advance to row number option.

DFX-7 Ultrasonic Flaw Detector

3.20 ESC Key

The ESC key is used in the MENU, MEAS, and EDIT functions as a back or escape function. If the DFX-7 is displaying a grid or sequential log, the OK key toggles the display options: RF, +RECT, -RECT and RECTFW views.

3.21 Arrow Keys

The Arrow Keys are used to navigate through the menus, increase/decrease values, and toggle specific function keys.

3.22 ENTER key

The ENTER key is used in the overall menu selection process, to activate list and edit boxes, display and save measurements/waveforms to grid or sequential file locations.

3.23 MULTI MODE Key

The MULTI MODE key provides the user with a set of flaw mode options: Normal, Peak, or Freeze. The normal mode is the standard flaw detector mode. The Peak mode draws, holds, and updates the waveform for the entire duration of the inspection. The Freeze mode ‘freezes’ the current waveform on the screen, allowing the user the time to analyze the wave.

3.24 ON/OFF Key

The ON/OFF key simply powers the unit either ON or OFF. Note: Unit will automatically power off when idle for 5 minutes. All current settings are automatically saved prior to powering off.

3.25 DFX-7 Overview

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In order to understand how to operate the DFX-7, it’s best to start off with an understanding of what we’re looking at. The DFX-7 has a lot of great features and tools that will prove to be a huge benefit for the variety of applications you’re constantly facing on a continual basis. Let’s have a brief look at the screens you’ll be looking at most often:

A. Repeatability/Stability Indicator – This indicator shows the

stability/repeatability of the sound path signal. When all the vertical bars are

fully illuminated, the repeatability of the sound path is stable. B. Battery Icon – Indicates the amount of battery life the DFX-7 has remaining. C. Height – Shows the signal amplitude height as a percent of 100% full screen

height. D. Feature Status Bar – Indicates the features currently enabled and in use in

the following order:

• Feature Toolkits i. Trig – Trigonometry w/ Curved Surface Correction

ii. AWS – American Welding Society iii. TCG – Time Corrected Gain iv. DAC – Distance Amplitude Correction

v. DGS – Distance Gain Size

• View i. RF: Radio Frequency.

ii. R+: Rectified positive. iii. R- : Rectified negative iv. FW: Rectified full wave.

DFX-7 Ultrasonic Flaw Detector

• Detect i. Zero crossing (ZX)

ii. Flank (FK)

iii. Peak (PK)

• Leg – Skip leg reference, (L1…L4…)

• High Speed Scan Mode

• Alarm Mode

• Gain Setting

E. Leg (skip leg) – Indicates which skip/leg the detection in on. The thickness of

the material is used to calculate the leg.

F. Hot Menu items – We call this menu section our “hot menu”, as these items

are the most commonly adjusted features, requiring quick access from the user. They can be displayed and scrolled by pressing the MEAS key at anytime. The ESC key is used in conjunction with MEAS key to reverse the direction scrolled.

G. Memory – Indicates that the currently displayed measurement screen and

values have been previous stored in memory. When MEM is displayed, all measurement functions are disabled until the user advances to an empty storage location, or the current measurement is cleared by pressing the CLR key.

H. Height – Displays the amplitude of the signal as a percentage of full screen

height. Depending on the quantity selected, this could also be displayed in

dB, or D. I. Grid or Seq Log Name – References the name of the log file currently open. J. Log File – Shows the storage cells of the current log file open. Depending on

the quantity currently selected, show either the %height or dB value stored. K. A-Scan Display – The actual echo reflections returned from the backwall or

defect.

3.26 Navigating the Hot Menu

The diagram above is a screenshot of the “Hot Menu” feature of the DFX-7. The Hot Menu’s contain all the most regularly adjusted features of the gauge. The primary

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purpose of the design, was to provide the user with an efficient way to make adjustments on the fly during inspections. The following procedure outlines the steps to navigate and make adjustments as follows:

Hot Menu

Gate1

1) Press the MEAS key once to activate the Hot Menu. Press the MEAS key multiple times to advance the cell right, and the ESC key multiple times to advance the cell left, until the WIDTH1 cell is highlighted.

2) Press the LEFT and RIGHT arrow keys to toggle the value or status.

Note: This is a coarse adjustment. It’s the fastest and easiest way to increment, decrement, or toggle the status, however it does so in coarse steps.

Set Detect

1) Press the UP and DOWN arrow keys until DETECT is highlighted.

2) Press the LEFT and RIGHT arrow keys to toggle the ABOVE or BELOW.

Note: Above will trigger the alarm when a signal meets or exceeds the height of the gate, and below will detect on anything that meets or is below the height of the gate.

3) Alternatively, press the ENTER key to display the Digits Edit Box.

4) Press the UP and DOWN arrow keys to scroll the highlighted value.

5) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

DFX-7 Ultrasonic Flaw Detector

6) Repeat steps 4 & 5 until the start position is correctly displayed.

7) Press the OK key to set the WIDTH1 position and return to the menu screen, or ESC to cancel entering the WIDTH1 position.

Note: This procedure is universal for all the features in the Hot Menu cell locations.

3.27 Top & Bottom End Caps

The top & bottom end panels are where all connections are made to the DFX-7. The diagram above shows the layout and description of the connectors:

Transducer Connectors

Refer to Diagram: The transducer connectors, and battery cover/probe zero disk are located on the DFX-7’s top end cap. The transducer connectors are of type LEMO “00”. A single element transducer must be plugged into the inside LEMO jack as illustrated above. Note: There is no polarity associated with connecting a dual element transducer to the DFX-7.

Battery Cover Refer to Diagram: The Battery cover is the large round disk shown in the diagram.

Be sure to check the polarity indicator diagram, located on the back label of the DFX-

7. Note: Rechargeable batteries can be used, however must be recharged outside

of the gauge in a standalone battery charger.

RS-232 Connector Refer to Diagram: The RS-232 connector, located on the bottom end cap, is a 2 pin

female Lemo connector. It is designed to connect directly from the DFX-7 to a standard AT serial port on a PC. The cable supplied with the DFX-7 is a Lemo to 9

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pin serial cable. Note: This connector is also used to upgrade the DFX-7 with the latest version of firmware.

USB Serial to USB Converter Cable

A converter cable can be attached to the 9 pin serial cable in needed (part no. N-402-

0510).

CHAPTER FOUR SETTING UP FOR MEASUREMENT

4.1 Selecting Display View

The DFX-7 includes a variety of viewing options for the waveform display. There are three primary options waveform options with selectable polarity. These are all outline below as follows:

Radio Frequency (RF): Displays the entire sine wave signal, much like an oscilloscope, from a reflector or return echo. This view shows both the positive and negative peaks.

Rectified (RECT): Displays half sine wave signal, either positive or negative, from the reflector or return echo. The user can select the polarity or “phase” displayed. This is typically determined by first using RF view to select the most optimal polarity “phase”, to fine tune the scopes settings. The RECT view is commonly used as the primary “flaw detection” view.

Full Wave (RECTFW): Display entire sine wave signal in a rectified view. There is no polarity.

The following procedure outlines the steps to select the view:

Display View

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the DISP menu is highlighted and displaying the submenu items.

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2) Use the UP and DOWN arrow keys to scroll through the sub menu items

until VIEW is highlighted.

3) Use the LEFT and RIGHT arrow keys to scroll the view options (RF,

+RECT, -RECT, RECTFW).

4) Once the view is displayed, press the MEAS key to return to measurement

mode.

4.2 Adjusting the display

This section will cover the procedures for adjusting the viewable range, or area, of the display, in terms of thickness. A basic overview example for this section would be as follows: Suppose we had a 50” widescreen television set. The left side of the television screen is considered the Delay for all view options. The right side of the television screen is the Range + Delay. By adjusting the left and right side of the television screen, to control the viewable area/range, we can zoom in and out of any part of the 50” screen we’d like, and focus on only the specific areas of the screen necessary.

Setting Delay

The Delay represents the left side of the display, and can be adjusted to start at any thickness value within the overall range of the DFX-7.

Note: Once the delay is set, it will remain the same for the views: RF, +RECT, RECT, RECTFW.

The procedures to adjust the Delay are outlined below:

Setting Delay

DFX-7 Ultrasonic Flaw Detector

1) Press the MEAS key once to activate measure menu items. Press the MEAS key multiple times to move right and the ESC key multiple times to move left, until the DELAY cell is highlighted.

2) Press the UP, DOWN, LEFT, and RIGHT arrow keys to scroll the highlighted value.

3) Alternatively, press the ENTER key to display the Digits Edit Box.

4) Press the UP and DOWN arrow keys to scroll the highlighted value.

5) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

6) Repeat steps 4 & 5 until the DELAY value is correctly displayed.

7) Press the OK key to return to the measurement screen, or ESC to cancel entering the DELAY.

8) Finally, press the MEAS key to return to the measurement screen.

Setting Range

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The Range is the distance from the delay that will be viewable on the screen. It can be adjusted to any value greater than the Delay. The procedures to adjust the range are outlined below:

Setting Range

1) Press the MEAS key once to activate measure menu items. Press the MEAS key multiple times to move right and the ESC key multiple times to

move left, until the RANGE cell is highlighted.

2) Press the UP, DOWN, LEFT, and RIGHT arrow keys to scroll the highlighted value.

3) Alternatively, press the ENTER key to display the Digits Edit Box.

4) Press the UP and DOWN arrow keys to scroll the highlighted value.

5) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

6) Repeat steps 4 & 5 until the RANGE value is correctly displayed.

7) Press the OK key to return to the measurement screen, or ESC to cancel entering the RANGE.

8) Finally, press the MEAS key to return to the measurement screen.

DFX-7 Ultrasonic Flaw Detector

4.3 Gain

The gain feature of the DFX-7 is used to adjust the signal amplitude to a predetermined reference height for the inspection process. The higher the gain the more the sound is amplified. The gain, or amplification of the return echoes, can be adjusted in the DFX-7 to accommodate a variety of applications. The setting of the gain is crucial in order to obtain valid readings during the inspection process.

Too much gain may result in erroneous measurements, by detecting on noise rather than the actual reflector or defect. Not enough gain may result in intermittent detection. It may also result in lack of detection on internal flaws, pits, or porosity. The gain can easily be compared to the volume control of a home stereo system. If you turn it up too much, you can’t hear the music clearly. If it’s turned down too much, you can’t hear it at all. The DFX-7 commands a 110dB gain range using 3 stages of amplification. The overall range makes the DFX-7 extremely versatile regarding a variety of applications and material types.

The procedures to adjust the Gain are outlined below:

Adjusting Gain

1) Press the MEAS key once to activate measure menu items. Press the MEAS key multiple times to move right, and the ESC key multiple times to

move left until the GAIN cell is highlighted.

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2) Press the UP, DOWN, LEFT, and RIGHT arrow keys to scroll the highlighted value.

3) Alternatively, press the ENTER key to display the Digits Edit Box.

4) Press the UP and DOWN arrow keys to scroll the highlighted value.

5) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

6) Repeat steps 4 & 5 until the GAIN value is correctly displayed.

7) Press the OK key to return to the measurement screen, or ESC to cancel entering the GAIN.

DFX-7 Ultrasonic Flaw Detector

The user can also access and adjust the gain from the tabbed menus. However, this method is more tedious than making the adjustments using the Hot Menus. The procedure using the tabbed menus is outlined below:

Adjusting the Gain using the Tabbed Menus

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab

left, until the TUNE menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until GAIN is highlighted.

3) Press the LEFT and RIGHT arrow keys to scroll the value. When the correct Gain is being displayed, proceed to step 8.

4) Alternatively, press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the Gain value is correctly displayed.

8) Press the OK key to set the Gain and return to the menu screen, or ESC to cancel entering the Gain.

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9) Finally, press the MEAS key to return to the measurement screen.

4.4 Gates

The gates are an important part of any ultrasonic device, in this case a flaw detector. The primary purpose of using a flaw detector is to “detect” and estimate the “size” of of flaws according to calibrated reference standards or simulated defects. The gates play an important role in this process, as without them a detection/measurement isn’t possible. The height of a gate is also a threshold, or controls the level of sensitivity. They can be adjusted to a specific reference height, based a predetermined reflector, and set to act as an alarm during the inspection process.

The more flexible a gate is, the better the possibilities for the user to setup an application. For example, a test block with a target size and depth is optimized on the A-Scan display with a signal amplitude at 70% full screen height. The inspector wants to know of any defects during the inspection that are greater than or equal in size to the calibrated test specimen. A gate is then enabled and set to a reference height of 70%. The width and range are adjusted to cover the range tested, and the inspection is underway.

The DFX-7 is equipped with 2 fully independent gates. Each gate has a start and stop or width, a threshold, a polarity switch, and a detect option. A gate can only detect on reflections that occur inside the boundaries of the gate. Anything outside of the start and range/width of the gate will be ignored. Both gates can be enabled and set for different detects, polarities, and positioned anywhere on the A-Scan display independent of one another. The following sections cover enabling and setting up gates:

4.5 Activating and Setting Up a Gate

DFX-7 Ultrasonic Flaw Detector

No Gate Gate On

The screenshots above show a rectified waveform with and without a gate enabled. The following steps outline how to enable a gate as follows:

Activating a Gate

Gate1

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the GT1 menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until ALARM is highlighted.

3) Press the LEFT and RIGHT arrow keys to toggle ALARM to ON. The menu items should now become active and adjustable, as the gate is now active.

Set Detect

1) Press the UP and DOWN arrow keys until DETECT is highlighted.

2) Press the LEFT and RIGHT arrow keys to toggle the ABOVE or BELOW.

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Note: Above will trigger the alarm when a signal meets or exceeds the height of the gate, and below will detect on anything that meets or is below the height of the gate.

Set Gate1 Start

1) Press the UP and DOWN arrow keys until GATE1 is highlighted, followed by pressing the LEFT and RIGHT arrow keys to scroll the value. When the correct start position is displayed, proceed to the next setting.

2) Alternatively, press the ENTER key to display the Digits Edit Box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

5) Repeat steps 3 & 4 until the start position is correctly displayed.

6) Press the OK key to set the GATE1 start position and return to the menu screen, or ESC to cancel entering the GATE1 start position.

Note: This where the gate first turn on relative to the horizontal axis or depth. Sets the left boundary of the gate, or where it turns on.

Set Gate1 Width

1) Press the UP and DOWN arrow keys until GATE1 WIDTH is highlighted, followed by pressing the LEFT and RIGHT arrow keys to scroll the value. When the correct width is displayed, proceed to the next setting.

2) Alternatively, press the ENTER key to display the Digits Edit Box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

5) Repeat steps 3 & 4 until the width is correctly displayed.

DFX-7 Ultrasonic Flaw Detector

6) Press the OK key to set the GATE1 WIDTH and return to the menu screen, or ESC to cancel entering the GATE1 WIDTH.

Note: This sets the overall width of the gate in terms of the horizontal axis or depth. Sets the right boundary of the gate, or where it turns off.

Set Threshold1 Level

1) Press the UP and DOWN arrow keys until THRESHOLD1 is highlighted, followed by pressing the LEFT and RIGHT arrow keys to scroll the value. When the correct threshold level is displayed, proceed to the next setting.

2) Alternatively, press the ENTER key to display the Digits Edit Box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

5) Repeat steps 3 & 4 until the threshold level is correctly displayed.

6) Press the OK key to set the THRESHOLD1 level and return to the menu screen, or ESC to cancel entering the THRESHOLD1 level.

Note: This sets the overall sensitivity level of the gate which is the threshold.

Select Gate Polarity

1) Use the UP and DOWN arrow keys to scroll through the sub menu items until POLARITY1 is highlighted.

2) Press the LEFT and RIGHT arrow keys to toggle the POLARITY feature positive or negative.

3) Press the MEAS key to return to the measurement screen.

Note: The GATE1 and WIDTH1 values can now be adjusted or tuned directly from the Hot Menus on the main measurement screen.

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Note: Sets where the detection will occur, on the negative or positive going echoes.

CHAPTER FIVE CALIBRATION

In this section we’ll focus on calibrating the DFX-7. There are a number of ways to go about performing a calibration, but we’ll be focusing on the simplest and most accurate method, which is performing a two point calibration. This method is very convenient, as it will automatically calculate the material velocity and zero using a minimum and maximum calibration standard of know thickness and material type. The DFX-7 can certainly be manually calibrated by adjusting the velocity and zero features, but this is a tedious and redundant process overall.

The two point calibration method can be used for both straight and angle beam transducers. A number of certified calibration standards are available to address inspection code requirements, specifications, and applications. It should be noted again that the DFX-7 has virtually 2 gauges built into a single gauge; a flaw detector, and a thickness gauge. Therefore, while the flaw detector option can be calibrated for straight beam contact and angle beam style transducers, the thickness gauge option contains a number of tools for using single and dual element style transducers with linearity tables and v-path correction curves. In addition, it should also be noted that the thickness gauge option has a fully functional scope with the same precision linearity as the flaw detector option. Therefore, the user should consider the current application to determine which gauge option will produce the best results. The following sections outline how to setup and calibrate your DFX-7 for field use, given a specific range and material type.

5.1 Setting Up For Calibration

This section covers performing a two point automatic calibration using a single element straight beam contact transducer with a range from 1 to 4 inches. In order to accomplish this, a set of calibration standards covering range is required. The steps are outlined as follows:

DFX-7 Setup

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The gauge will require a few basic adjustments in order to get underway with the calibration process. For this example, in order to avoid multiple steps for setting the gauge features/options, the default setup will be loaded as a starting point. However, the user should invest the necessary time getting to know the features and options included in the DFX-7, as well as gaining a good understanding of their function:

Loading Default Setup

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the SEUTP menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until DEFAULT SETUP is highlighted.

3) Press the ENTER key to display the CONFIRM screen.

4) Press the OK key to load the DEFAULT SETUP.

Setting the Range

1) Press the MEAS key once to activate the measure menu items. Press the MEAS key multiple times to move right and the ESC key multiple times to

move left, until the RANGE cell is highlighted.

DFX-7 Ultrasonic Flaw Detector

2) Press the ENTER key to display the Digits Edit Box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

5) Repeat steps 3 & 4 until the desired range value is displayed.

6) Press the OK key to set the value and return to the GT1 menu. Note: Our range calibration range for this example is 4 inches. Therefore

setting a range of 5 inches will enable the user to view the entire range on the display.

Enabling and Setting Up a Gate

Refer to the illustrations above. In order to measure, a gate is required. The width of the gate should be small enough, in terms of its width, in order to select specific reflections to measure. The screenshot above shows a gate enabled to select the 1 inch calibration standard, and in the second the 4 inch calibration standard.

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Activating a Gate

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the GT1 menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until ALARM is highlighted.

3) Press the LEFT and RIGHT arrow keys to toggle the gate ON.

Setting the Detect

1) Use the UP and DOWN arrow keys to scroll through the sub menu items until DETECT is highlighted.

2) Press the LEFT and RIGHT arrow keys to toggle the option ABOVE.

Gate1 Start

1) Use the UP and DOWN arrow keys to scroll through the sub menu items until GATE1 is highlighted.

2) Press the ENTER key to display the Digits Edit Box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

DFX-7 Ultrasonic Flaw Detector

5) Repeat steps 3 & 4 until the desired GATE1 value is displayed. Note: In our example, a value less than 1 inch should be selected.

6) Press the OK key to set the value and return to the GT1 menu.

Gate1 Width

1) Use the UP and DOWN arrow keys to scroll through the sub menu items until GATE1 WIDTH is highlighted.

2) Press the ENTER key to display the Digits Edit Box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

5) Repeat steps 3 & 4 until the desired GATE1 WIDTH value is displayed.

Note: In our example, a value greater than 1 inch should be selected.

6) Press the OK key to set the value and return to the GT1 menu.

Threshold Level

1) Use the UP and DOWN arrow keys to scroll through the sub menu items until THRESHOLD1 is highlighted.

2) Press the ENTER key to display the Digits Edit Box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

5) Repeat steps 3 & 4 until the desired THRESHOLD1 value is displayed.

Note: In our example, a value of 20% has been selected. However, the user should set a value that will be close enough to the baseline to avoid a “Peak Jump”, or missing the first cycle.

6) Press the OK key to set the value and return to the GT1 menu.

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Setting Polarity

1) Use the UP and DOWN arrow keys to scroll through the sub menu items until POLARITY1 is highlighted.

2) Press the LEFT and RIGHT arrow keys to toggle the polarity POSITIVE.

3) Press the MEAS key to return to the measurement screen and get started with the two point calibration.

5.2 Straight Beam Calibration

Now that the DFX-7 is setup with a valid range and a gate enabled, we’re ready to perform a two point, calibration using a single element contact style transducer, as follows:

Two Point Calibration – Straight Beam

Note: Calibration standards representing the minimum and maximum

thickness of the overall inspection range intended are required. They must also be of the same material type as the intended application. For our example, we’ll be using a 1 and 4 inch standard for calibration.

DFX-7 Ultrasonic Flaw Detector

Coupling to the 1” Cal Standard (1st Point)

Apply a drop of couplant on the transducer and place the transducer in steady contact with the 1” calibration standard. Be sure that the reading is stable and the repeatability indicator, in the top left corner of the display, is fully lit and stable. Also, be sure there is sufficient signal amplitude in order to avoid ‘peak jumping’ or missing the first cycle.

Adjusting the Gate

1) Press the MEAS key once to activate the measure menu items. Press the MEAS key multiple times to move right and the ESC key multiple times to

move left, until the GATE1 cell is highlighted.

2) Press the LEFT and RIGHT arrow keys to move the gate over the waveform to be measured, as demonstrated in the screen shot above.

Note: In order to trigger on a signal, the waveform must be inside the boundaries of the gate.

Calibrating the First Point

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the CAL menu is highlighted and displaying the submenu items, as shown in the screenshot above.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until MATL 1PT is highlighted.

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3) Press the ENTER key to display the Digits Edit Box.

4) Press the UP and DOWN arrow keys to scroll the highlighted value.

5) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

6) Repeat steps 4 & 5 until the known thickness value is correctly displayed.

7) Press the OK key to calculate the velocity and return to the menu screen, or ESC to cancel the one point calibration.

Apply a drop of couplant on the transducer and place the transducer in steady contact with the 4” calibration standard. Be sure that the reading is stable and the repeatability indicator, in the top left corner of the display, is fully lit and

DFX-7 Ultrasonic Flaw Detector

stable. Also, be sure there is sufficient signal amplitude in order to avoid ‘peak jumping’ or missing the first cycle.

Adjusting the Gate

1) Press the MEAS key once to activate the measure menu items. Press the MEAS key multiple times to move right and the ESC key multiple times to

move left, until the GATE1 cell is highlighted.

2) Press the LEFT and RIGHT arrow keys to move the gate over the waveform to be measured, as demonstrated in the screen shot above.

Note: In order to trigger on a signal, the waveform must be inside the boundaries of the gate.

Calibrating the Second Point

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until MATL 2PT is highlighted.

3) Press the ENTER key to display the Digits Edit Box.

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4) Press the UP and DOWN arrow keys to scroll the highlighted value.

5) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

6) Repeat steps 4 & 5 until the known thickness value is correctly displayed.

7) Press the OK key to calculate the velocity and return to the menu screen, or

ESC to cancel the one point calibration.

Note: A velocity and zero value will be calculated and displayed in the fields a

shown above.

8) Finally, press the MEAS key to return to the measurement screen. In order to trigger on anything that’s detected in the calibrated range, the

boundaries of the gate must be adjusted to include the entire range. Caution: in both z-cross & flank detection settings, the first signal to cross the gate will be triggered on. However, if the peak detection setting has been enabled, the signal with the most amplitude will be detected.

DFX-7 Ultrasonic Flaw Detector

Adjusting the Gate to Calibrated Range

1) Press the MEAS key once to activate the measure menu items. Press the MEAS key multiple times to move right and the ESC key multiple times to

move left, until the GATE1 cell is highlighted.

2) Press the LEFT and RIGHT arrow keys to move the gate start to a position less than 1 inch.

3) Press the MEAS key once to highlight the WIDTH1 cell.

4) Press the LEFT and RIGHT arrow keys to move the gate start to a position greater than 4 inches.

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Note: CHECK YOUR CALIBRATION! Place the transducer back on the one inch point, and any others in the given range, to confirm linearity. If the velocity and zero values we calculated correctly, the thickness reading will match the known thickness of the calibration standards. If the thickness is not correct, repeat the steps above.

5) Press the OK key once to display the thickness, or the MEAS key to return to the hot menus at any time.

5.3 Angle Beam Calibration

In the first example we demonstrated how to perform a two point calibration using a single element straight beam contact transducer. With the exception of a handful of additional comments, calibration using an angle beam transducer is virtually identical in the scope of the overall step by step process. To avoid copying the procedures from the previous section, we’ll focus only on the additional comments. Refer to section 5.1 and 5.2, regarding the procedures to setup and calibrate the DFX-7. The following are a list of additional items to consider when using an angle beam transducer, as follows:

Calibration Standards:

There are a number of calibration block options available in a variety of common material types, and according to specific code requirements. The user should consider the application, codes applicable, and purchase the necessary calibration standards.

DFX-7 Ultrasonic Flaw Detector

Shear versus Longitudinal Velocity:

Unlike the previous straight beam calibration, which uses a longitudinal wave, an angle beam transducer uses a shear wave. The following is a brief review of the waves:

• Longitudinal –

o Particle motion is parallel to the direction of wave travel. o Travels in solids, liquids, and gasses. o Fastest mode of vibration.

• Shear –

o Particle motion is perpendicular to the direction of wave travel. o Travels only in solids. o Is approximately ½ the velocity of longitudinal waves. o Has a shorter wavelength than a longitudinal at the same frequency.

Therefore, a two point calibration using an angle beam transducer will result in a velocity approximately ½ the speed of the velocity calculated from the straight beam calibration in the previous section.

Gain and Amplitude Ratio:

During an angle beam calibration the overall amplitude height of the waveform is critical for “peaking up”. Therefore the maximum amplitude of the waveform must be visible on the display in order to correctly position the transducer on the calibration standard. The user should select a screen height and gain level that will enable the entire waveform to be visible on the display.

Peaking Up the Signal Amplitude:

During an angle beam calibration, it’s important to peak up the overall amplitude of the waveform to its maximum potential. The primary purpose is to be sure the transducer is positioned properly on the calibration standard, that’s producing return echoes at different distances. For example: If the operator is using a DSC block to calibrate the velocity and zero, a DSC block will produce echoes at 3 & 7 inches. The operator then positions the transducer on an index point, moves the transducer in both directions forward and backward, rotates it side to side, and watches the signal amplitude to find the maximum potential. At the maximum potential, the transducer is correctly positioned to measure both multiple echoes at the correct distances, and ready to proceed with the calibration.

Selecting the Material Type:

The user can also select a material type directly from a table built into the DFX-7 with shear wave values. This would only get the user close, in terms of velocity, to the calibration standards material type. In order to display the material chart with shear

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wave values, the TRIG mode must be enabled. The following outlines the steps to enable the shear wave velocity table and select a material type from the chart:

Selecting the Material Type

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the TRIG menu is highlighted and displaying the submenu items.

2) Press the LEFT and RIGHT arrow keys to toggle TRIG mode ON.

3) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the CAL menu is highlighted and displaying the submenu items.

4) Use the UP and DOWN arrow keys to scroll through the sub menu items until MAT is highlighted.

5) Press the ENTER key to display the list of material types.

6) Press the UP and DOWN arrow keys to scroll through the material list until the appropriate material is highlighted.

DFX-7 Ultrasonic Flaw Detector

7) Press the ENTER key to select the material type and initiate the overwrite confirmation screen.

8) Press the OK key to confirm the material selection, or ESC key to cancel changing the material type.

CHAPTER SIX TRIGONOMETRY MODE

6.1 Introduction to TRIG

Trig mode is most commonly used for inspecting welded joints using an angle beam transducer. Based on the location, orientation, and geometry of the weld, a straight beam transducer is typically not suitable for inspection. As a result, a transducer emitting sound at a given angle will allow the operator to position the transducer away from the actual weld, and “skip” into the weld at a given angle. Therefore, in order to determine the location of a defect, given a specific angle, the trigonometry mode is used. This section will cover the steps to setup and utilize trigonometry mode.

6.2 Additional Comments

Prior to proceeding on to the next section outlining how to enable and setup the TRIG mode, a few additional items should be clarified:

Angle Beam Transducer Weld Inspection

Refer to the Angle Beam Transducer diagram above: SP – Sound Path X-Offset – Front of wedge less Index Angle – Transducer Angle SD – Surface Distance Thickness – Material Thickness Depth – Depth of flaw from surface

Screenshot Trig mode:

DFX-7 Ultrasonic Flaw Detector

When TRIG mode is enabled, the calculated measurements will be displayed below the waveform display area at (A), and the signal amplitude as a percentage of full screen height at (B).

Curved Surface Correction:

The DFX-7 will also compensate for convex curved surfaces of longitudinally welded pipes. A curved surface will produce a greater sound path than a flat surface will, using a transducer with a given angle. The user should consider the angle used on curved surfaces, with respect to the material thickness, in order to be sure a reflection will occur from the opposite surface of the test material. In order to utilize the curved surface compensation, the outside diameter must be entered into the DFX-7.

6.3 Setup Trigonometry Mode

This section provides a step by step procedure to enable and setup the TRIG mode. Note: A two point calibration should be done prior to proceeding. Refer to Chapter

Five for the calibration procedures.

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Activating & Setting the Parameters

Activate Trig Mode

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the TRIG menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until TRIG is highlighted.

3) Press the LEFT and RIGHT arrow keys to toggle the TRIG feature ON. The menu items should now become active and adjustable, as illustrated above.

Enter Material Thickness

1) Press the UP and DOWN arrow keys until THICKNESS is highlighted, followed by pressing the LEFT and RIGHT arrow keys to scroll the value. When the correct thickness is displayed, proceed to the next setting.

2) Alternatively, press the ENTER key to display the Digits Edit Box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

DFX-7 Ultrasonic Flaw Detector

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

5) Repeat steps 3 & 4 until the thickness is correctly displayed.

6) Press the OK key to set the THICKNESS and return to the menu screen, or

ESC to cancel entering the THICKNESS.

Note: Thickness is used to calculate the depth.

Transducer Angle

1) Press the UP and DOWN arrow keys until ANGLE is highlighted, followed by pressing the LEFT and RIGHT arrow keys to scroll the value. When the correct angle is displayed, proceed to the next setting.

2) Alternatively, press the ENTER key to display the Digits Edit Box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

5) Repeat steps 3 & 4 until the angle is correctly displayed.

6) Press the OK key to set the ANGLE and return to the menu screen, or ESC to cancel entering the ANGLE.

X-Offset

1) Press the UP and DOWN arrow keys until X-OFFSET is highlighted, followed by pressing the LEFT and RIGHT arrow keys to scroll the value. When the correct X-Offset is displayed, proceed to the next setting.

2) Alternatively, press the ENTER key to display the Digits Edit Box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

5) Repeat steps 3 & 4 until the X-Offset is correctly displayed.

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6) Press the OK key to set the X-OFFSET and return to the menu screen, or

ESC to cancel entering the X-OFFSET.

Note: The X-Offset is used for purposes of marking, and is physically

measured with a ruler from the index point to the front edge of the transducer.

Curved Surface Outside Diameter

1) Press the UP and DOWN arrow keys until CSC OD is highlighted, followed by pressing the LEFT and RIGHT arrow keys to scroll the value. When the correct CSC OD is displayed, proceed to the next setting.

2) Alternatively, press the ENTER key to display the Digits Edit Box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

5) Repeat steps 3 & 4 until the CSC OD is correctly displayed.

6) Press the OK key to set the CSC OD and return to the menu screen, or ESC to cancel entering the CSC OD.

Note: The CSC OD value is only used for curved surfaces of longitudinally welded pipes.

CHAPTER SEVEN AWS – WELD INSPECTION

7.1 Introduction to AWS

AWS provides a toolkit for evaluating defects according to the American Welding

Society D1.1 welding code. The code offers inspectors a method to classify discontinuities by calculating and Indication Rating (IR) using ultrasonics. This toolkit can be used in conjunction with TRIG mode, outlined in the previous chapter, to simultaneously display the sound path (SP), surface distance (SD), and depth (D). The following sections provide an outline for using the AWS feature.

7.2 Additional Comments

Since the DFX-7 is a gain controlled instrument, the following formula applies:

A – B – C = D Where: A = Discontinuity Indication Rating (DI) B = Reference Indication Level (IL) C = Attenuation Factor (AF); or 2(SP – 1) SP = sound path in inches (2dB loss per inch of material thickness) D = Indication Rating (IR)

Note: all values are in dB.

Calibration Standards & Calibration:

In order to use the AWS feature, the operator must have calibration standards made with the same size reflector at different distances within the testing range. The standards should also be made of the same material type as the material to be inspected.

AWS D1.1 Standard:

There are specific transducers that are required by the D1.1 standard. The frequency specified by the standard is 2-2.5MHz. The user should refer to the standard for further information.

7.3 Setup AWS

This section provides a step by step procedure to enable and setup the AWS feature. Note: A two point calibration should be done prior to proceeding. Refer to Chapter Five for the calibration procedures. The TRIG mode will also be used for weld

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inspection, and should additionally be setup prior to enabling the AWS feature. Refer to Chapter Six for instructions on setting up TRIG mode.

Activating & Setting AWS

Activate Trig Mode

1) Press the MENU key once to activate the menu items tab. Press the MENU

key multiple times to tab right, and the ESC key multiple times to tab left, until the AWS menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items

until AWS is highlighted.

3) Press the LEFT and RIGHT arrow keys to toggle the AWS feature ON. The

menu items should now become active and adjustable, as illustrated above.

Enter % Screen Height

1) Press the UP and DOWN arrow keys until % SCRN HEIGHT is highlighted,

followed by pressing the LEFT and RIGHT arrow keys to scroll the value. When the correct height is displayed, proceed to the next setting.

2) Alternatively, press the ENTER key to display the Digits Edit Box.

DFX-7 Ultrasonic Flaw Detector

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

5) Repeat steps 3 & 4 until the height is correctly displayed.

6) Press the OK key to set the % SCRN HEIGHT and return to the menu screen, or ESC to cancel entering the % SCRN HEIGHT.

Note: % Screen Height is an arbitrary level, and is not specified by the AWS D1.1. The user should set a value that will optimize viewing defects that are larger and smaller than the reference level. Typically this level is set between 50%-80% full screen height.

Setting the Reference Gain

1) Press the UP and DOWN arrow keys until SET REF HEIGHT is highlighted, followed by pressing the LEFT and RIGHT arrow keys to toggle the feature ON.

2) Press the MEAS key once to activate measure menu items. Press the MEAS key multiple times to move right and the ESC key multiple times to move left, until the GATE1 cell is highlighted.

Note: A gray cursor should be visible in the waveform area of the display. Also, since the DFX-7 has been previous calibrated and the TRIG feature has been setup, a gate should be enabled and active.

Peak Up on the Reflector

1) Apply couplant on the calibration standard, place the transducer in the correct area in position with the reflector, and slide the transducer around to locate the maximum amplitude.

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2) Press the LEFT and RIGHT arrow keys to position the start of GATE1 to trigger on the waveform.

3) Optionally, press the MEAS key multiple times to move right and the ESC key multiple times to move left, until the WIDTH1 cell is highlighted.

4) Press the LEFT and RIGHT arrow keys to adjust the size or width of

GATE1.

Note: When the signal is in the gate, the height indicator will detect and display

the % full screen height.

Setting the Level

1) Press the MEAS key multiple times to move right and the ESC key multiple times to move left, until the AWS BOX: cell is highlighted.

2) Press the LEFT and RIGHT arrow keys to position the cursor box over the waveform.

3) Press the ENTER key to set the REFGN (reference gain).

Note: This process can be repeated and reset multiple times, or until the SET REF GAIN feature is toggled OFF.

4) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the AWS menu is highlighted and displaying the submenu items.

5) Press the UP and DOWN arrow keys until SET REF GAIN is highlighted, followed by pressing the LEFT and RIGHT arrow keys to toggle OFF.

6) Finally, press the MEAS key to return to the main measurement screen, followed by pressing the OK key to display the AWS screen.

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Note: The AWS screen can be toggle on by pressing the OK key while in the main measurement screen. Equally, the Hot Menus can be toggled by pressing the MEAS at any time.

CHAPTER EIGHT DISTANCE AMPLITUDE CORRECTION (DAC)

8.1 Introduction to DAC

A DAC curve is a gate with a variable threshold to compensate for a given reflector type and size measured at different depths. Unlike a standard gate, which typically has a fixed threshold level regardless of the depth, the DAC curve is more representative of the reflector size at different depths. In order to generate a DAC curve, calibration standards must made with the same material being inspected, the representative reflector size, and over a given thickness range. The DAC curve is then used as an alarm to inform the user about the size of any given reflector at any depth during the inspection process.

Once the DAC curve has been established, the user can display; -2dB, -6dB, -10dB,

-12dB, -6/-12dB, -6/-14dB, DAC or GATE at any time. The initial DAC curve generated is always displayed in conjunction with any of the above CURVE options. Additionally, the alarm can be set to TRIGGER on any of the curve options displayed. Therefore, if the -6/-12dB curve option has been selected, the user can toggle the

TRIGGER options: GATE, DAC, -6dB, or -12dB.

Note: Based on the screen resolution of the DFX-7, the dynamic range of the DAC

is approximately 18dB. As a result, inspection of any materials that attenuate more than 18dB over the inspection range, the DAC feature should not be used, and TCG (Time Corrected Gain) should optionally be considered.

8.2 Additional Comments

Prior to proceeding onto the next section to create a DAC curve, a few additional items will help with the users selection process in the menu items:

• Up to 8 points can be used to generate a DAC curve.

• 3 or more points must be used in order to draw a DAC curve.

• All the DAC curve or gate combinations only detect when the amplitude of the

signal is ‘at’ or ‘above’ the selected trigger option.

• Any of the DAC curves or gate displayed, can be set as the trigger alarm option.

• The measure (meas) options are as follows:

dB – %DAC – At the DAC curve represents 100%. Any signal generating an

amplitude below the DAC curve is less than 100%, and any above greater than 100%.

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%FSH – The top of the waveform display represents 100% full screen height. Any waveform amplitudes generated greater than 100% full screen height will not be displayed. 100% is the greatest value that can be displayed.

Note: The MEAS option selected is overridden with %FSH while the DAC curve is in DRAW mode. Once the DRAW mode is turned off, the select MEAS option will be displayed.

• The MEAS, CURVE, and TRIGGER options can be changed at any time once the DAC curve has been created.

• In order to move the highlighted cursor over a waveform to use as a point in generating the DAC curve, the “DAC BOX:” hot menu item in the main measurement screen must be highlighted.

8.3 Creating a DAC Curve

This section provides a step by step procedure to create a DAC curve. Note: a two point calibration should be done prior to proceeding. Refer to Chapter Five for the calibration procedures. Also, if the TRIG function will be used, it should be setup prior to proceeding. Refer to Chapter Six for the setup procedure.

Activating & Setting the Parameters

Activating DAC

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the DAC menu is highlighted and displaying the submenu items.

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2) Use the UP and DOWN arrow keys to scroll through the sub menu items until DAC is highlighted.

3) Press the LEFT and RIGHT arrow keys to toggle the DAC feature ON or AUDIBLE. The menu items should now become active and adjustable, as illustrated above.

Activating Draw Mode

1) Press the UP and DOWN arrow keys until DRAW is highlighted, followed by pressing the LEFT and RIGHT arrow keys until ON is displayed.

Quantity Displayed

1) Press the UP and DOWN arrow keys until MEAS is highlighted, followed by pressing the LEFT and RIGHT arrow keys to toggle and select dB, %FSH, or %DAC.

Selecting the Curve(s)

1) Press the UP and DOWN arrow keys until CURVE is highlighted, followed by pressing the LEFT and RIGHT arrow keys to toggle and select DAC, -2, - 4, -6, -10, (-6/-12), or (-6/-14) curve options. The CURVE option can be changed at any time after the DAC curve has been created.

Setting the Curve(s) Trigger

1) Press the UP and DOWN arrow keys until TRIGGER is highlighted, followed by pressing the LEFT and RIGHT arrow keys to toggle and select which curve or gate to use as the alarm trigger. The options displayed will vary according to which CURVE option has been selected above: DAC, -2, -4, -6,

-10, (-6/-12), or (-6/-14) curve options. The Trigger option can be changed at any time after the DAC curve has been created.

2) Proceed to the next section – Drawing the DAC.

Drawing the DAC

DFX-7 Ultrasonic Flaw Detector

1) With all the parameters set in the previous section, press the MEAS key once to return to the main measurement screen.

Note: The user should now see a highlighted cursor displayed in the waveform area, starting at the left most side of the display area.

ex. 1 ex. 2

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2) Press the MEAS key multiple times to move right, and the ESC key multiple times to move left until the DAC BOX: cell is highlighted. Now that the DAC BOX: cell is highlighted, the cursor can be controlled by moving the LEFT and RIGHT arrow keys.

3) Couple the transducer to the first calibration standard, and peak up on the reflector, adjusting the gain to keep the signal height within the boundaries of the waveform display area, and at a suitable height to allow for attenuation at greater depths in the overall range to be tested.

4) Press the LEFT and RIGHT arrow keys to move the cursor over the waveform to be used as the first point in the DAC curve, and press the ENTER key to set the first point. Illustrated in ex.1 above.

5) Repeat steps 3 & 4 to set multiple points as is necessary. Illustrated in ex.2 above.

Note: The DAC curve will be displayed after 3 points have been set/recorded,

and will continue to be redrawn/updated for each additional point added, with a maximum of 8 points allowed.

6) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the DAC menu is highlighted and displaying the submenu items.

DFX-7 Ultrasonic Flaw Detector

7) Press the UP and DOWN arrow keys until DRAW is highlighted, followed by pressing the LEFT and RIGHT arrow keys until OFF is displayed. The DAC curves are now set and ready to be used for inspection.

CHAPTER NINE TIME CORRECTED GAIN (TCG)

9.1 Introduction to TCG

The TCG feature increases gain as distance increases, in order to achieve an overall level of sensitivity for the same reflector at different distances. It is very similar to the DAC feature noted in a previous chapter. However, while a DAC curve plots points at given amplitudes and distances, generating a variable threshold, the TCG feature increases the gain at various distances to adjust the signal amplitude to a predetermined level of full screen height. Therefore, the amplitude of all signals at various distances will be displayed at the same reference level.

Note: One of the advantages of the TCG feature over the DAC option is the dynamic range. The TCG feature has a maximum dynamic range of 50dB, while the DAC option is approximately 18dB. Therefore the TCG feature is a better solution for any materials that attenuate more than 18dB over the inspection range, and should be considered.

9.2 Additional Comments

Prior to proceeding onto the next section to create a DAC curve, a few additional items will help with the users selection process in the menu items:

• Up to 8 points can be used to generate a TCG curve.

• 3 or more points must be used in order to draw a TCG curve.

• The gain will be adjusted at each point to display the signal amplitude at a

predetermined reference level.

• In order to move the highlighted cursor over a waveform to use as a point in generating the TCG curve, the “TCG BOX:” hot menu item in the main measurement screen must be highlighted.

9.3 Creating a TCG Curve

This section provides a step by step procedure to create a TCG curve. Note: a two point calibration should be done prior to proceeding. Refer to Chapter Five for the calibration procedures. Also, if the TRIG function will be used, it should be setup prior to proceeding. Refer to Chapter Six for the setup procedure.

Setting TCG Parameters

DFX-7 Ultrasonic Flaw Detector

Activating TCG

4) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the TCG menu is highlighted and displaying the submenu items.

5) Use the UP and DOWN arrow keys to scroll through the sub menu items until TCG is highlighted.

6) Press the LEFT and RIGHT arrow keys to toggle the TCG feature ON. The menu items should now become active and adjustable, as illustrated above.

Enter % Screen Height

7) Press the UP and DOWN arrow keys until % SCRN HEIGHT is highlighted, followed by pressing the LEFT and RIGHT arrow keys to scroll the value. When the correct height is displayed, proceed to the next setting.

7) Alternatively, press the ENTER key to display the Digits Edit Box.

8) Press the UP and DOWN arrow keys to scroll the highlighted value.

9) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

10) Repeat steps 3 & 4 until the height is correctly displayed.

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11) Press the OK key to set the % SCRN HEIGHT and return to the menu screen, or ESC to cancel entering the % SCRN HEIGHT.

Activating Draw Mode

4) Use the UP and DOWN arrow keys to scroll through the sub menu items until DRAW is highlighted.

5) Press the LEFT and RIGHT arrow keys to toggle the DRAW feature ON.

6) Proceed to the next section – Drawing the TCG curve.

Drawing the TCG

1) With all the parameters set in the previous section, press the MEAS key once to return to the main measurement screen.

Note: The user should now see a highlighted cursor displayed in the waveform area, starting at the left most side of the display area.

DFX-7 Ultrasonic Flaw Detector

ex. 1 ex. 2

2) Press the MEAS key multiple times to move right, and the ESC key multiple times to move left until the TCG BOX: cell is highlighted. Now that the TCG BOX: cell is highlighted, the cursor can be controlled by moving the LEFT and RIGHT arrow keys.

3) Couple the transducer to the first calibration standard, and peak up on the reflector to achieve maximum signal amplitude.

4) Press the LEFT and RIGHT arrow keys to move the cursor over the waveform to be used as the first point in the TCG curve, and press the ENTER key to set the first point. Illustrated in ex.1 above.

5) Repeat steps 3 & 4 to set multiple points as is necessary. Illustrated in ex.2 above.

Note: You must set 3 points to draw a TCG curve. Any point can be cleared

by pressing the CLR key when DRAW is active.

6) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the TCG menu is highlighted and displaying the submenu items.

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7) Press the UP and DOWN arrow keys until DRAW is highlighted, followed by pressing the LEFT and RIGHT arrow keys until OFF is displayed. The TCG curve is now set.

8) Optionally, the TCG curve can be displayed by pressing the UP and DOWN arrow keys until CURVE is highlighted, followed by pressing the LEFT and RIGHT arrow keys toggle ON.

9) Press the MEAS key to display the main measurement screen, and the TCG curve will be displayed.

CHAPTER TEN ADDITIONAL FEATURES OF THE DFX-7

10.1 Material Velocity

The DFX-7 has a built in feature to manually adjust the material velocity to a know value in the calibration section of the DFX-7. It should be noted that this does not calculate the zero value like the two point calibration option does. Therefore, if the material velocity is changed you should check the calibration. The procedures for adjusting the velocity are outlined below:

Adjusting Velocity

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until VELCITY is highlighted.

3) Press the LEFT and RIGHT arrow keys to scroll the value. When the correct velocity value is being displayed, proceed to step 8.

4) Alternatively, press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

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6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the velocity value is correctly displayed.

8) Press the OK key to set the velocity and return to the menu screen, or ESC to cancel entering the velocity.

9) Finally, press the MEAS key to return to the measurement screen.

10.2 Zero

The DFX-7 has a feature to manually adjust the electronic zero. This feature used in conjunction with manually adjusting the velocity, are the primary features necessary to perform a ‘crude’ manual screen calibration. The procedure for adjusting the zero is listed below:

Adjusting Zero

DFX-7 Ultrasonic Flaw Detector

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until ZERO is highlighted.

3) Press the LEFT and RIGHT arrow keys to scroll the value. When the correct zero value is being displayed, proceed to step 8.

4) Alternatively, press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the zero value is correctly displayed.

8) Press the OK key to set the zero and return to the menu screen, or ESC to cancel entering the zero.

9) Finally, press the MEAS key to return to the measurement screen.

10.3 Material Velocity Charts

The DFX-7 has two material velocity charts built into the gauge with both longitudinal and shear material velocities. It should be noted that in order to display the chart containing the shear wave velocities the TRIG mode must be activated, as we’ve assumed an angle beam transducer will be used for the inspection process. The procedure is listed below:

Selecting a Basic Material Type

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2) Use the UP and DOWN arrow keys to scroll through the sub menu items until MAT is highlighted.

3) Press the ENTER key to display the list of material types.

4) Press the UP and DOWN arrow keys to scroll through the material list until the appropriate material is highlighted.

5) Press the ENTER key to overwrite the material type and display the menu items with the new material type selected.

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6) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

10.4 Auto Find

The DFX-7 is equipped with a very handy feature for locating the detection point of a return echo that is not currently in the viewable region of the display. The AUTO FIND feature is a convenient way to automatically bring the detected echo into view on the display. Once the echo is in the viewable area, the user can then make small adjustments to the delay and range accordingly. The procedure to use the AUTO

FIND feature is outlined below:

Using Auto Find

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the UTIL menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until AUTO FIND is highlighted.

3) Place the transducer on the test material and obtain a reading.

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4) Press the ENTER key to automatically adjust the display settings and bring

the waveform into view.

5) Once the signal is displayed, press the MEAS key to return to measurement

mode.

10.5 Brightness

The DFX-7 is equipped with a brightness feature to adjust the display visibility and optimize battery life. It has an arbitrary scale with a values from 1-20, with 20 representing the brightest setting. The procedures for adjusting the brightness are outlined below:

Adjusting Brightness

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until BRIGHTNESS is highlighted.

DFX-7 Ultrasonic Flaw Detector

3) Press the LEFT and RIGHT arrow keys to scroll the value. When the correct brightness value is being displayed, proceed to step 8.

4) Alternatively, press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the brightness number is correctly displayed.

8) Press the OK key to set the brightness and return to the menu screen, or ESC to cancel entering the brightness.

9) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

10.6 Color Scheme

The DFX-7 has a variety of display color options to select from. These will change the look and feel of the according to the users preference. The procedures for changing the VIEW, are outlined below:

Selecting a Color Scheme

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2) Use the UP and DOWN arrow keys to scroll through the sub menu items until VIEW is highlighted.

3) Press the ENTER key to display a list of the color scheme options.

4) Press the UP and DOWN arrow keys to scroll through the material list until the appropriate material is highlighted.

5) Press the ENTER key, followed by pressing the OK key, to overwrite the current color scheme with the selected scheme.

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6) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

10.7 DIM

The DFX-7 has a built-in DIM feature to manage power more effectively. This feature has adjustable time durations, until the power of the display is dimmed and current draw reduced. The timer is constantly reset while the user is making measurements, and is only activated when the gauge is idle for the duration of time the DIM value is set for. This feature does not override the preset 5 min idle power off feature in any way. However, if the gauge is turned on, set for a DIM of 120sec, and then left idle for 5 minutes, the DFX-7 will dim in 2 minutes, then power off in 5 minutes. The procedures for adjusting the DIM time are outlined below:

Setting a DIM time

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until DIM is highlighted.

3) Press the LEFT and RIGHT arrow keys to scroll the DIM time.

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4) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

10.8 Graphics Options (look & feel)

The DFX-7 includes a couple of cosmetic features for user preference when viewing the waveform. These features only serve as cosmetic items, and do not change the functionality of the DFX-7 in any way.

RECT Wave:

The rectified wave feature, is only functional when using RECT wave view, and provides the user the following display options:

Outline – Draws the unfilled outline of the waveform.

Filled – Draws a filled version of the waveform.

DFX-7 Ultrasonic Flaw Detector

The procedure to select the look and feel option is outlined below:

Setting the Look & Feel

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until RECT WAVE is highlighted.

3) Use the LEFT and RIGHT arrow keys to scroll the RECT WAVE options.

4) Once the RECT WAVE is displayed, press the MEAS key to return to the measurement screen.

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10.9 Detect Mark

Another look and feel option of the DFX-7 is the DETECT MARK feature. The detect mark give the user the option to select: none, line, dots, or box. Depending on the select made, an indication will be displayed on the waveform, showing where the detection is occurring. It should be noted that the “box” option will only be visible in RF view. The following screenshots illustrate the above selection options:

None Line

Dots Box

10.10 Polarity

The DFX-7 has a number of features and views that offer selectable polarity. The important thing to note is the polarity view is entirely different than the polarity selection of a gate. If a polarity view of +RECT is selected, only the positive portion of the waveform will be shown on the screen. If a positive polarity is then selected for GT1, not only will the gate be displayed on the screen, it will only detect on the positive going cycles of the waveform. Polarity is selectable according to the VIEW, GT1, GT2, and DAC. Again, view corresponds only to what portion of the waveform is displayed, positive or negative, and the other three options are primarily associated with where the detect occurs. Finally, if the view is set to RF, the entire waveform cycle will be displayed, both positive and negative. Refer to the diagram below:

DFX-7 Ultrasonic Flaw Detector

The diagram above is an RF view, showing both the positive and negative going cycles for purposes of explanation. Notice the +/- positions in the diagram. The positive phase is everything above the horizontal center line, and the negative everything below the center line. The baseline is found at position (A), and considered zero dB. If +RECT was selected as the view, only the positive portion of the waveform would be displayed. Equally, if the gate polarity was set to positive, as in the diagram at (C), it would also appear on the display. However, if it was set to negative, would not appear on the display. In the example above, the gate is set to positive and will detect on the positive going waveform cycles shown in the box (B).

Toggle Polarity (+/-)

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Note: The screenshots above show where all the possible locations for polarity selection are found in the DFX-7. For more information on the above, refer to the sections on VIEW, DAC, GT1, & GT2.

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the DISP, DAC, GT1, or GT2 menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until VIEW, DPOLARITY, POLARITY1, or POLARITY2 is highlighted.

3) Use the LEFT and RIGHT arrow keys to toggle the VIEW, DPOLARITY, POLARITY1, or POLARITY2 negative or positive.

4) Press the MEAS key to return to the measurement screen and begin taking readings.

10.11 Detect Modes

The DFX-7 has three selectable modes of detection: Z-Cross, Flank, and Peak. The following diagram illustrates the difference between the options:

DFX-7 Ultrasonic Flaw Detector

Z-Cross Flank Peak

Refer to the diagrams above. The current polarity is positive, as shown by the position of the gate above the baseline:

Z-Cross:

and goes negative. Flank: The detection occurs as the first half cycle left edge rises and breaks the

threshold. Peak: The detection occurs at the highest peak in the gate.

The procedure to select the DETECT MODE is outlined below:

The detection occurs as the first positive half cycle crosses the baseline

Selecting the Detect

5) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the TUNE menu is highlighted and displaying the submenu items.

6) Use the UP and DOWN arrow keys to scroll through the sub menu items until DETECT MODE is highlighted.

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7) Use the LEFT and RIGHT arrow keys to scroll the DETECT options.

8) Once the DETECT is displayed, press the MEAS key to return to the

measurement screen.

10.12 Pulse Width

The DFX-7 has a square wave pulser with adjustable pulse width option. Pulse width, refers to the duration of time the pulser is left on. This time results in increased energy sent into the test material. There are three width options (SPIKE, THIN, and WIDE). The SPIKE setting may be desirable for high resolution and general applications to decrease the overall noise. When additional energy is needed, more penetration, the THIN and WIDE options may be necessary. The standard setting is THIN. The procedure to change the pulse width is outlined below:

Selecting the Pulse Width

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the TUNE menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until PULSE is highlighted.

3) Use the LEFT and RIGHT arrow keys to scroll the Pulse options.

DFX-7 Ultrasonic Flaw Detector

4) Once the Pulse is displayed, press the MEAS key to return to the

measurement screen.

10.13 Pulser Voltage

The DFX-7 has a 200 volt square wave pulser that can be adjusted for specific applications and transducers. The Pulser Volt feature offers a 50 volt cut/boost option to the user. The standard setting is 200 volts. This enables the DFX-7 to offer greater penetration for difficult material types, or increased resolution on noisy materials. The procedure to change the pulser voltage is outlined below:

Changing the Pulser Voltage

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until PULSER VOLT is highlighted.

3) Use the LEFT and RIGHT arrow keys to scroll the PULSER VOLT options.

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4) Once the desired Pulser Voltage is displayed, press the MEAS key to

return to the measurement screen.

10.14 Screen Update (Refresh)

The DFX-7 has a maximum screen redraw rate of 120Hz. While it’s extremely fast for a digital flaw detector, it also requires additional power as it draws more current. As a result, we’ve opted to include an option to toggle between 60Hz and 120Hz in order to provide the user the option to conserve on battery life. The procedure to toggle this option is outlined below:

Selecting the Refresh

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the PRB menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until SCREEN UPDATE is highlighted.

3) Use the LEFT and RIGHT arrow keys to toggle 60Hz or 120Hz.

4) Once the desired SCREEN UPDATE is displayed, press the MEAS key to return to the measurement screen.

DFX-7 Ultrasonic Flaw Detector

10.15 Pulse Repetition Frequency (PRF)

The DFX-7 is equipped an adjustable pulse repetition rate, with adjustable settings of 8, 16, 32, 66, 125, 250, and 333Hz. The primary purpose is to control how fast the pulser is firing. The repetition rate is tied into the alarm LEDS. Therefore, when scanning at higher speeds, a higher repetition rate will make the alarm trigger more responsive. It’s important to note that since the screen has a maximum refresh rate of 120Hz, or draws at 120 times a second, any PRF settings over this maximum will not be visible on the display. In fact, the human eye has a response rate of less than 60Hz.

The PRF setting will automatically be overridden according to the range set by the user. Long range settings will slow the PRF down automatically. Slower PRF settings will save on battery life. Therefore, if your current application doesn’t call for fast scanning speeds, you can save battery life by selecting a slower PRF. The procedure to change the MAX PRF setting is outlined below:

Setting the Max PRF

5) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the PRB menu is highlighted and displaying the submenu items.

6) Use the UP and DOWN arrow keys to scroll through the sub menu items until MAX PRF is highlighted.

7) Use the LEFT and RIGHT arrow keys to scroll the PRF options.

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8) Once the desired PRF is displayed, press the MEAS key to return to the

measurement screen.

10.16 Damping

The DFX-7 has an adjustable damping feature, enabling the user to select from a variety of settings according the transducer frequency and overall output. The range of the damping feature is 50-1500 ohms. The available steps are 50, 75, 100, 300, 600 and 1500 ohms. Lower frequency transducers require less damping because they typically have higher impedance and distort. The reverse is true for higher frequency transducers. Nevertheless, trial and error with this feature will enable you to find the optimal signal response and setting for your transducer. The procedure to change the DAMPING is outlined below:

Selecting the Damping

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until DAMPING is highlighted.

3) Use the LEFT and RIGHT arrow keys to scroll the DAMPING options.

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4) Once the desired DAMPING is displayed, press the MEAS key to return to

the measurement screen.

10.17 Filters (Wide & Narrow Bands)

There are two versions of the DFX-7 series: DFX-7 and DFX-7+. The DFX-7 is a wide band only gauge, which includes a single wide band filter with a range of

1.8MHz to 19MHz. The DFX-7+ includes the same wide band filter, but also includes

a few narrow band filter options at 2MHz, 5MHz and 10MHz. The wide band option is responsive to all signals within the given frequency range. However, narrow band filters eliminate signals outside of the target filter frequency, and focus on the output of the transducer at the specified frequency. The procedure to change the

DAMPING is outlined below:

Selecting the Damping

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until FILTERS is highlighted.

3) Use the LEFT and RIGHT arrow keys to scroll the FILTERS options.

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4) Once the desired FILTERS is displayed, press the MEAS key to return to

the measurement screen.

10.18 Peak Hold

The DFX-7 includes a peak hold feature that draws and saves the maximum waveform amplitude on the screen. This allows an inspector to move the transducer in all directions, in an effort to “peak up” on a signal, and locate the maximum amplitude. The following procure outlines the steps to activate and use the PEAK hold feature:

Activating Peak

1) Press the MULTI MODE key located in the bottom left corner of the keypad

to display the mode options.

2) Use the UP and DOWN arrow keys PEAK is highlighted.

3) Press the MEAS key to return to the measurement screen.

Clearing Current Wave Draw

Note: At any point during a PEAK scan the operator may opt to clear the wave

drawing and start over.

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1) Press the CLR key at any time to clear the currently displayed waveform, and continue the scanning process.

Disabling PEAK

Note: In order to deactivate the PEAK hold feature.

1) Press the MULTI MODE key located in the bottom left corner of the keypad to display the mode options.

2) Use the UP and DOWN arrow keys NORMAL is highlighted.

3) Press the ENTER key to set the mode and automatically return to the measurement screen.

10.19 Freeze Waveform

The DFX-7 also includes a FREEZE mode that allows an operator the ability to freeze a the current waveform being display on the screen at anytime. Once the operator freezes the waveform, the transducer can be removed from the test material. The following procure outlines the steps to activate and use the FREEZE feature:

Activating Peak

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Note: Assuming the operator currently has a waveform that they’d like to freeze on the display.

1) Press the MULTI MODE key located in the bottom left corner of the keypad

to display the mode options.

2) Use the UP and DOWN arrow keys FREEZE is highlighted.

3) Press the ENTER key to set the mode and automatically return to the

measurement screen.

Disabling Freeze

Note: In order to deactivate the FREEZE feature.

3) Press the MULTI MODE key located in the bottom left corner of the keypad

to display the mode options.

4) Use the UP and DOWN arrow keys NORMAL is highlighted.

5) Press the ENTER key to set the mode and automatically return to the

measurement screen.

CHAPTER ELEVEN DATA STORAGE – SETUP, EDIT, & VIEW FILES

11.1 Introduction to Grid and Sequential file formats

The DFX-7 is equipped with two data file format options, GRID LOG and SEQ LOG. The GRID file format is very similar to a spreadsheet format found in popular software programs like Excel. A GRID is simply a table of readings. A location in a grid is specified by giving a row and column coordinate. The rows are numbered from 1 to 999 and the columns are labeled from A to ZZ (999 Rows & 52 Columns). The sequential file format can be viewed as a file as a single column of up to 512 possible rows (readings), and a column of corresponding identifiers associated with each individual reading. The identifier can be a combination of up to 10 numeric, alpha, or special characters listed above, while the file name can consist of a combination of up to 20 of the same character set. Note: The identifier cannot start or end with a special character. Once a start and end ID are entered into the DFX-7 and the log created, the DFX-7 will automatically generate all the identifiers within that range.

The following character set listed below are all the allowable characters that will be used for both file formats: GRID & SEQ LOG. Any combination of these characters can be used for creating a Name and Note regardless of the selected format. The allowable characters are as follows:

Numeric characters: 0 – 9 Alpha Characters: A – Z Special Characters: ! ‘ _ # space / . – ( )

Multiple grids can be created and stored until the DFX-7’s memory is full. If the user attempts to store a new file in the DFX-7 and the size of the file exceeds the capacity of memory, the DFX-7 will respond with an error message indicating that the memory is unable to store the new file.

The DFX-7 can store a total of 8,000 readings with a corresponding screenshot of the RF or RECT views with every reading, as well as all the DFX-7 settings for every individual reading. If the graphics option is disabled, not saving screenshots, the DFX-7 can store a total of 210,000+ readings. The screenshot stored with the reading will depend on what view the DFX-7 was in at the time it was saved. For example, if the view was in RECT, then a RECT will be saved with the reading.

In the sections that follow, the procedures for creating, using, and editing GRID’s and SEQ LOG’s have been combined together for the purpose of similarity in overall functionality and structure. The illustrations below are snapshots of typical GRID and SEQ LOG file formats:

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Grid File Formats

Sequential Log Formats

Important Note: For the duration of this chapter, all references to GRIDS and SEQ LOGS should be considered synonymous with references to FILES.

11.2 Creating a new Grid or Sequential Log (File)

Important Note: This entire section is a step by step guide to successfully create a

grid or sequential log. The instructions must be used in the sequential order specified, as follows:

Checkline DFX-7 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual