OPERATOR’S MANUAL DFX-444
DFX-444 Operator’s Manual ii Issue 3
DFX-444 Operator’s Manual Issue 3 2002 Dakota Ultrasonics All rights reserved. Information in this document is subject to change without notice. No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording for any purpose without the express written permission of Dakota Ultrasonics Dakota Ultrasonics 300 El Pueblo Road, #100 Scotts Valley, CA 95066 Ph. (831) 431-9722 Fax.
DFX-444 Operator’s Manual Issue 3 TABLE OF CONTENTS TABLE OF CONTENTS.......................................................... iv Table of Figures................................................................. vii 1. Disclaimers And Notices................................................. 1 1.1 Specific Warnings. .................................................... 1 1.2 General Warnings...................................................... 1 1.3 Operator Training.................................
DFX-444 Operator’s Manual Issue 3 5.3 Flaw Detection ......................................................... 26 5.4 Thickness Gauging ................................................. 27 6. Detailed Operation Instruction..................................... 29 6.1 Basic Menu Functions ............................................ 29 6.1.1 Main Menu ....................................................... 30 6.1.2 Function Menu ................................................ 37 6.1.3 Memory Menu.....
DFX-444 7.2 Operator’s Manual Issue 3 Battery Charging ..................................................... 91 8. Interface Connections................................................... 92 8.1 RS232........................................................................ 93 8.2 Composite Video..................................................... 94 8.3 Proportional Output ................................................ 95 9. Specifications.........................................................
DFX-444 Operator’s Manual Issue 3 Table of Figures Figure 1 – Basic Ultrasonic Testing..........................................................9 Figure 2 – Ultrasonic Energy Field Distribution......................................12 Figure 3 – Ultrasonic Beam Spread and Half-Angle ..............................13 Figure 4 – Typical Dual Element Transducer/probe ..............................14 Figure 5 – Thickness Gauging on Pipe..................................................
DFX-444 Operator’s Manual Issue 3 1. Disclaimers And Notices The following information must be read and understood by any user of a Dakota Ultrasonics flaw detector and thickness gauge. Failure to follow these instructions can lead to serious errors in test results or damage to the flaw detector. Decisions based on erroneous results can lead to property damage, personal injury or death.
DFX-444 1.3 Operator’s Manual Issue 3 Operator Training Operators must receive adequate training before using this ultrasonic flaw detector. Operators must be trained in general ultrasonic testing procedures and in the set-up and performance required by each specific test or inspection. Operators must understand: A. Sound wave propagation theory. B. Effects of the velocity of sound in the test material. C. Behavior of the sound wave at the interface of two different materials. D.
DFX-444 Operator’s Manual Issue 3 transmitted echoes. The sound velocity of the test piece multiplies this time in order to obtain an accurate distance or thickness reading. Since the actual sound velocity in materials can vary from the published values, the best result is obtained when the instrument is calibrated on a reference block made from the same material as the test piece. This block should be flat, smooth and as thick as the maximum thickness expected of the test piece.
DFX-444 Operator’s Manual Issue 3 with temperature variations. All calibrations should be performed on site with test blocks at or near the same temperature as that expected on the test piece, to minimize errors. E. Transducer/probe Condition. The transducer/probe used for testing must be in good condition, without noticeable wear of the front surface.
DFX-444 Operator’s Manual Issue 3 Neither The Seller Nor The Manufacturer Shall Be Liable Either In Contract Or In Tort For Any Direct Or Indirect Loss Or Damage (Whether For Loss Of Profit Or Otherwise), Costs, Expenses Or Other Claims For Consequential Or Indirect Compensation Whatsoever (And Whether Caused By The Negligence Of The Company, Its Employees Or Agents Or Otherwise). 1.7 Electromagnetic Compatibility This product conforms to the European Directive 89/336/EEC.
DFX-444 Operator’s Manual Issue 3 2. How to Use this Manual This manual has been designed so that a person with a good knowledge of the basics of ultrasonic nondestructive testing may understand the operation and use of the features offered by the DFX-444. The user is advised, however, of the important nature of ultrasonic nondestructive testing and is referred to Section 1 for important information on the proper use of this technology.
DFX-444 Operator’s Manual Issue 3 3. Features of the DFX-444 The DFX-444 is a user-friendly ultrasonic digital flaw detector and thickness gauge, which is simple to use and provides the experienced ultrasonic operator with a full-function device that incorporates many productivity enhancing features. All of the features of the DFX-444 are accessed through a menu system under the control of tactile touch keypads. 3.
DFX-444 Operator’s Manual Issue 3 Functional Testing Methods The DFX-444 supports the following ultrasonic testing methods: • • Pulse-Echo Flaw Detection Transmit-Receive Flaw Detection • Time of flight measurement • Contact or Immersion Methods • Angle Beam (Shear Wave) Testing • Angle Beam (Surface Wave) Testing • Crack Diffraction Methods • Depth of Flaw Measurement • Single Transducer/probe Thickness Measurement • Dual Transducer/probe Thickness Measurement • Indirect Measurement o
DFX-444 Operator’s Manual Issue 3 4. Fundamentals of Ultrasonic Testing The DFX-444 is a single-channel ultrasonic inspection instrument used for the inspection of homogeneous materials for the presence of inclusions, porosity and other discontinuities that could affect the performance of materials and components. It can also be used for thickness gauging of homogeneous materials, requiring access from only one side of the test piece.
DFX-444 Operator’s Manual Issue 3 far side of the test piece and reflect back to the transducer/probe where they are converted into electronic signals and a measurement is obtained. This technique, derived from sonar and radar, has been widely applied to nondestructive inspection and dimensional measurement processes. 4.
DFX-444 Operator’s Manual Issue 3 a function of the frequency and the velocity of sound in the test material according to the following equation: λ = Where: λ v f v f = wavelength = velocity of sound in the material = frequency of the transducer/probe In addition, higher frequency transducer/probes tend to have better resolution due to shorter energy bursts and the smaller wavelength.
DFX-444 Operator’s Manual Issue 3 Figure 2 – Ultrasonic Energy Field Distribution The near field distance is a function of the transducer/probe frequency, diameter, and the sound velocity in the test material according to the following equation: Where: D = diameter of the transducer/probe element D2 f Y+ = 0 4c f c = frequency of the transducer/probe = velocity of sound in the material 12
DFX-444 Operator’s Manual Issue 3 Transducer/probes also exhibit a characteristic called beam spread. The sound beam tends to spread as a function of the distance from the transducer/probe as represented in Figure 3 Figure 3 – Ultrasonic Beam Spread and Half-Angle below. Beam spread is an important consideration when inspecting discontinuities that may be close to geometric features of the test piece such as corners and fillets.
DFX-444 Operator’s Manual Issue 3 It can be seen from this relationship that beam spread can be controlled by selecting a transducer/probe with a combination of higher frequency or larger element diameter. 4.3 Straight Beam Testing Straight beam testing is the introduction of the sound energy normal to the test piece surface utilizing longitudinal or compression waves. A longitudinal wave is one in which the particle motion is in the same direction as the propagation of the wave.
DFX-444 Operator’s Manual When using dual element transducer/probes it is important to follow good practices in the use of the couplant. Any excess buildup of couplant could cause readings that are thicker than actual. This is because the couplant can add to the measured value. When measuring small diameter piping, always place the split in the transducer/probe across the pipe and use only enough couplant to obtain the reading as shown in Figure 5.
DFX-444 4.5 Operator’s Manual Issue 3 Angle Beam Testing Angle beam testing is the introduction of sound energy at an angle to the surface of the test piece. In most angle beam testing, the wave energy is mode converted from a longitudinal wave to a shear wave by the refraction principle using a transducer/probe as shown in Figure 7. A shear wave is one in which the particle motion is perpendicular to the direction of propagation.
DFX-444 Operator’s Manual Issue 3 The transducer/probe wedge is usually manufactured from a polymer material so that the difference is sound velocity is large enough to produce the desired refraction. Angle beam or shear wave testing is most often used for the inspection of welds. The reason for this is to be able to position the transducer/probe Figure 8 – Typical Weld Inspection away from the weld bead yet propagate energy into the weld zone.
DFX-444 4.6 Operator’s Manual Issue 3 Immersion Testing Immersion ultrasonic testing is used to automate the process and to provide improved reliability for testing and test piece coverage. Immersion testing offers the advantages of more uniform coupling, increased testing speeds and the ability to focus the sound beam. All of these factors can lead to improved sensitivity and reliability. Most immersion testing uses single element transducer/probes with a focusing lens applied to the front face.
DFX-444 Operator’s Manual Issue 3 In order to compensate for the shortening of the focal length, the following equation can be used to calculate a correct water path distance from the transducer/probe to the test piece surface: Figure 10 – Focusing in Immersion Testing WP Where: WP MP F Cm Cw C = F - MP m C w = water path = metal path = focal length in water = sound velocity in the test material = sound velocity in water In addition to the refraction effect on the focal length, s
DFX-444 Operator’s Manual Issue 3 5. Quick Start 5.1 Front Panel Controls The front panel controls consist of a series of blue and yellow sealed, pressure sensitive, tactile buttons that facilitate the changing of instrument setting and the movement through the menus on the screen. These buttons are described below along with the mnemonics used throughout this manual.
DFX-444 Operator’s Manual Button/Mnem Issue 3 Description “Power On” push button and “Power Off” push button for switching the instrument On and Off. Operates as a toggle. PWR N.B Random lines or characters may be displayed for a second or two after switch on, before the memory is initialized, this is normal. STEP Press to select the dB step value of amplifier gain as 0.5, 2, 6, 14, or 20dB.
DFX-444 Operator’s Manual Button/Mnem OK OK INC DEC MEMORY MEM Issue 3 Description This button operates in conjunction with the memory menus to accept a Store or to accept a Recall of a memory already in storage. In the print mode, OK acts as the print button. This button operates in connection with the plain yellow buttons next to the parameter boxes to increase the value or step the selection in the positive direction.
DFX-444 Operator’s Manual Button/Mnem FREEZE PEAK FZ/PK Issue 3 Description Press this button once to select Freeze mode for the AScan display. This is a useful feature for holding an echo for evaluation. When in this mode, a box is highlighted showing FREEZE below the graticule. Pressing the button a second time selects Peak mode, which holds and updates all echoes on the display during inspection.
DFX-444 Operator’s Manual Button/Mnem Issue 3 Description The four yellow buttons on the right side of the display are used to select the menu boxes, which appear on the right side of the A-Trace. When a menu box is selected, it will be highlighted. Some menu boxes contain a single or double arrow point indicating slow or fast adjustment mode. Press the button next to the selected box a second time to toggle between slow and fast modes.
DFX-444 Operator’s Manual Issue 3 menus to reset various functions. A reset function is provided to facilitate the returning of all panel calibration settings to the factory defaults. To reset panel settings to factory defaults: 1. Switch the instrument off. 2. Depress the yellow MEM button and hold while switching the instrument on until the reset display is seen. 3. Press the UP/RT button to reset the instrument to factory defaults.
DFX-444 Operator’s Manual Issue 3 Clearing the memory: The DFX-444’s memory is comprised of all the stored A-Logs, TLogs and calibration set-ups. Erasing all of these values accidentally could have far reaching consequences. Should the occasion arise for a need to erase all of the memory, call the factory for instructions . 5.3 Flaw Detection Perform the following steps to establish a basic flaw detection mode for the DFX-444. Units shown are in mm.
DFX-444 Operator’s Manual Issue 3 5. In the GATE1 menu, set the following parameters: a) STATE to ON +VE b) START to 10.0 c) WIDTH to 50 or other suitable value to cover the test range of interest. d) LEVEL to 50.0 6. In the GATE2 menu, set the STATE to OFF 7. In the MEAS menu, set the following parameters: a) MODE to DEPTH b) TRIGGER to FLANK c) HUD to OFF d) T-MIN to OFF 8. In the Function/DAC menu, set the MODE parameter to OFF You are now prepared to perform basic flaw detection.
DFX-444 Operator’s Manual Issue 3 3. When making a quick adjustment on a menu parameter, press the adjacent yellow button until the double arrow appears next to the parameter name. This establishes the fast scroll using the INC and DEC buttons. 4. In the CAL menu, set the following parameters: a) ZERO can be left alone b) VEL can be left alone c) RANGE to 125 or other suitable value to cover the test range of interest. d) DELAY to 0.00 e) GAIN to 50.0 5.
DFX-444 Operator’s Manual Issue 3 d) T-MIN to OFF 8. Calibrate the thickness readout on the selected calibration block using the procedure in Section 6.5.2, “A-Cal” on page 82. You are now prepared to perform basic thickness gauging. Adjust parameters as necessary to optimize the calibration. For more in-depth features of the DFX-444, see Section 6.5, “Thickness Gauging” on page 78. 6.
DFX-444 Operator’s Manual Issue 3 6.1.1 Main Menu The Main menu is the power on default menu and can be reached from the Function menu and the Memory menu by pressing their respective buttons a second time. CALibration Menu ZERO VEL Used to calibrate the screen and thickness readout for zero offsets that are inherently different for each transducer/probe. Units are microseconds in both mm and inch modes.
DFX-444 Operator’s Manual Issue 3 AMPlifier Menu FREQ DETECT Used to set the center frequency band of the amplifier to match the transducer/probe. Ranges are 1, 2, 5, 10 narrow bands and WIDE band 1.5 to 15 MHz (-6dB). Used to set the video detection and display mode for the desired rectification of the signals from RF, -VE HW (negative halfwave), +VE HW (positive halfwave), and FW (full-wave). FREQ 5.0 MHz DETECT FULL REJECT 0 REF 37.
DFX-444 Operator’s Manual Issue 3 GATE1 & GATE2 Menus STATE START Set the state of the gate as follows: +VE: The alarm triggers when an echo in the gate exceeds the threshold level. -VE: The alarm triggers when an echo in the gate falls below the threshold level. Usually used to monitor for loss of back wall echo. EXPAND: Expands the gate width to fill the horizontal display width. Only applies to gate 1. OFF: Switches the gate off.
DFX-444 Operator’s Manual Issue 3 MEASurement Menu In the measurement menu, the top selection box shows the selected measurement mode and the remaining three selection boxes vary depending on the mode selected as follows: MONITOR MODE: In this mode, gates 1 and 2 act as two independent monitor gates.
DFX-444 Operator’s Manual Issue 3 E-E MODE: In this mode, gate 1 functions as a thickness monitor and measures the thickness between the first signal in the gate and the second signal in the gate that reaches or exceeds the level threshold. A second bar is shown representing the blanking (see BLANK). BLANK This function sets the blanking distance, as a percentage of the total gate width, which is a blind zone after the first echo, after which a second echo can be measured.
DFX-444 Operator’s Manual Issue 3 PROBE Menu ANGLE Set to the nominal refracted angle of the transducer/probe to calibrate the Surface and Depth measurements. X -OFFSET Used to enter the distance from probe emission point to front of probe case. This is used by the TRIG function in MEAS menu to give the surface distance. ANGLE 45.0 X_OFF 0.0 REF 37.5 When highlighted, this cursor allows a second GAIN main menu to be selected by 53.5 pressing the CURR control.
DFX-444 Operator’s Manual Issue 3 PRINT Menu This menu allows printing of information to a suitable serial printer connected to the RS232 serial port on the DFX-444. Please note that this requires a printer with a serial port. OFF The PRINT mode is switched OFF DISPLAY With the Print mode in Display, the screen display will be sent to the printer when the OK button is pressed.
DFX-444 Operator’s Manual Issue 3 6.1.2 Function Menu Press the FN button to access the Function menu. Press it again to return to the Main menu. When moving in and out of the Function menu, the position of the cursors in the Main menu remains in their previous positions. A-CAL Menu This menu provides automatic calibration of sound velocity and transducer/probe zero. Gate 1 is used to select the reference echoes. The calibration procedure is described fully in Section 6.5.2 on page 82.
DFX-444 Operator’s Manual Issue 3 DAC Distance Amplitude Correction Menu This menu is used to create DAC curves using a series of reference echoes. Once drawn, the DAC curve acts as an alarm threshold level for the gate where the level varies to match the attenuation and field characteristics of the transducer/probe and test material combination. The calibration procedure is described fully in Section 6.4.2 on page 62. ON MODE: Displays the DAC curve on the screen.
DFX-444 Operator’s Manual Issue 3 TCG Time Corrected Gain Menu This menu is used to create TCG curves using a series of reference echoes. Once drawn, the TCG curve acts as swept gain control on the amplifier to set different gain levels relative to distance. The calibration procedure is described fully in Section 6.4.3 on page 65. ON MODE: Activates the TCG curve to adjust the gain. Can be activated in RF or rectified display modes. CURVE When switched ON, the TCG curve is displayed.
DFX-444 Operator’s Manual AWS Menu This menu is used when performing weld inspection in accordance with the American Welding Society’s Structural Welding Code, ANSI/AWS D1.1-94. It provides a convenient method to automatically calculate the Indication Rating as defined in the code. The calibration procedure is described fully in Section 6.4.5 on page 71. Issue 3 MODE MEAS IL dB 61.4 AF dB 3.0 IR dB - 7.2 SET MODE: Used to set up the AWS measurement mode. REF Used to set the Indication Level.
DFX-444 Operator’s Manual Issue 3 UTILities menu UNITS Selects INCHES, µs, or METRIC measurement units. Microseconds, µs, is a useful mode when using Time of Flight Diffraction techniques (TOFD). When in µs mode, the Velocity is fixed at 2000 m/s (5000 in/µs) and is not adjustable. CLICK When on, a beep will sound to confirm each button press. ALARM When set to AUDIBLE, a buzzer will sound during any gate alarm. UNITS INCHES CLICK ON ALARM MUTE SMOOTH ON REF 37.5 GAIN 53.
DFX-444 Operator’s Manual Issue 3 VIDEO Menu COLOR (Color Display) Selects one of eight Color schemes for the display. COLOUR BAKLIGHT (LCD display) Turns the backlight on or Off, Using the backlight improves visibility in poor lighting, but significantly increases power consumption, reducing battery life BRIGHT BRIGHTness (Color Display Controls the display brightness. The level selected will affect the battery duration.
DFX-444 Operator’s Manual Issue 3 When highlighted, this cursor allows a second FN menu to be selected by pressing the CURR button. When highlighted, this cursor allows return to the first FN menu by pressing the CURL button. P_O/P Proportional Output Control Menu This menu controls the analog and digital proportional outputs. Two outputs are provided one for depth and one for amplitude. The outputs are active when the associated gate is triggered. Switching on the outputs will reduce battery duration.
DFX-444 Operator’s Manual Issue 3 CLOCK Menu TIME SET: Used to set the current time. HOURS Used to set the current hour in 24hour format. SET TIME HOURS 20 MINS Used to set the current minutes. SET DATE: Used to set the current date. (Selected by pressing TIME key, then DEC) MINS DATE Used to set the current day number. C MONTH Used to set the current month number. 50 REF 37.5 YEAR Used to set the current year. NOTE: Be sure to press OK to save the new CLOCK settings. 44 GAIN 53.
DFX-444 Operator’s Manual Issue 3 6.1.3 Memory Menu Press the MEM button to access the Memory menu. Press it again to return to the Main menu. When moving in and out of the Memory menu, the positions of the cursors in the Main menu remain in their previous positions. PANEL Setup Menu This menu provides storage and recall of up to 20 calibration setting. The use of this feature is described fully in Section 6.3 on page 56. STORE Used to select a storage location (1-20).
DFX-444 Operator’s Manual Issue 3 The EDIT NOTES function is used to edit the notes in the current calibration set in memory (it is not the one in the selected Store) Data can be edited via the keypad or via the Dakota Ultrasonics keyboard. These are the steps to follow if the keyboard is connected. KEYBOARD FUNCTION Connect the keyboard to the AUXiliary socket on the front panel of the set. The connector is a 5pin one. Press EDIT NOTES from the keypad to enter the keyboard function.
DFX-444 Operator’s Manual Issue 3 LEFT ARROW Press the KEY to move the cursor left. RIGHT ARROW Press the KEY to move the cursor right. END OF LINE Press the End KEY to move the position of the cursor to the end of line. HOME Press the Home KEY to move the cursor to the initial position. Ctrl Press the Ctrl KEY to clear the screen. EXIT Press the Esc KEY to exit back to the PANEL or A-LOG menu. Store the calibration set to save the notes.
DFX-444 Operator’s Manual Issue 3 If the keypad is used to enter data then: EDIT NOTES: NEXT LINE Press to bring up the editing boxes as follows: Use the CURL and CURR buttons to move the cursor horizontally along a text line. Use the UP/RT and DN/LT buttons to highlight a character from the map. Press OK to write a character to a line and press MEM to clear all text. Press to scroll through and select a line for editing.
DFX-444 Operator’s Manual Issue 3 A-LOG Menu This menu provides storage and recall of up to 100 A-Scans with settings. The use of this feature is described fully in Section 6.4.6 on page 73. STORE RECALL MODE: DELETE MODE: LIST MODE: Used to select a storage location (1-100). Used to recall a stored A-Scan and settings to the active memory. Press OK to recall. The display comes up in FREEZE mode. Press FZ/PK to remove. Used to delete a VALID (used) AScan and its settings. Press OK to delete.
DFX-444 Operator’s Manual Issue 3 REF Menu This menu allows a waveform stored in A-LOG memory to be displayed as a reference on the display. Before a waveform can be recalled, it must be stored in an A-LOG location STORE Used to select a storage location (1-100). STORE 1 RECALL MODE: Used to recall a stored A-Scan and display it. Press OK to recall. LIST MODE: Shows the notes associated with the stored A-Scan. Pressing OK will recall the waveform.
DFX-444 Operator’s Manual Issue 3 T-LOG Menu This menu provides storage and recall of up to 2,000 thickness readings. Numeric and Sequential modes are available as selected in the T-FN menu. This feature is described fully in Section 6.5.4 on page 84 Numeric Mode: Readings are stored under a three level code, starting with BLOCK (1-14), followed by LOC ation (1-2000) and NO (1-2000). BLOCK BLOCK Used to select the block number (1-14) for storage or viewing of a thickness reading.
DFX-444 Operator’s Manual Issue 3 Sequential Mode: Readings are stored by LOCation (1-2000) number only. In this mode location and historical thickness data can be downloaded to the DFX-444 from a computer, a fixed series of four notes can be added to a location, and any of the 20 PANEL store settings can be assigned to a location. Note: The HUD is on automatically in sequential mode. LOC THICK NOTES AUTO SET Used to select the location number for storage or viewing of a thickness reading.
DFX-444 Operator’s Manual Issue 3 T-FN Menu MODE Set the mode to PRINT to print the selected blocks and locations to the printer on the RS232 port. PRINT Set the mode to DELETE to delete the selected blocks and locations. Press OK again after the confirmation prompt. ALL BLOCK Used to select the block number for printing or deletion. Decrement below 1 to select ALL blocks for printing or deletion. ALL LOC Used to select the location number for printing or deletion.
DFX-444 6.
DFX-444 Menu MEM Operator’s Manual Sub-Menu Issue 3 Parameters UTILities UNITS CLICK ALARM SMOOTH VIDEO COLOR / BAKLIGHT BRIGHT / CONTRAST VIDEO GRATICULE P_O/P MODE O/P1 O/P2 TRIGGER CLOCK âSETâ TIME HOURS MINS DATE DATE MONTH YEAR STORE âMODEâ STORE STATE EDIT* RECALL STATE EDIT* DELETE STATE EDIT* LIST STATE INDEX STATE PANEL A-LOG REF STORE STORE âMODEâ STORE STATE EDIT* RECALL STATE EDIT* DELETE STATE EDIT* LIST STATE INDEX STATE âMODEâ RECALL
DFX-444 Menu Operator’s Manual Sub-Menu *EDIT Function 6.3 Issue 3 Parameters NEXT LINE INSERT CHAR DELETE CHAR EXIT Storage & Recall of Calibration Setups After the DFX-444 has been properly calibrated for a particular testing scheme, it is possible to store all of the panel settings for subsequent recall when performing the same test at a later time.
DFX-444 Operator’s Manual Issue 3 6. Press the blue OK button to store the panel settings. 7. If you forgot to enter Notes, create the Notes as described below and the re-save the panel settings starting at step 5 above.
DFX-444 Operator’s Manual Issue 3 To recall a panel set: Follow the above procedure but set the MODE parameter to RECALL and then press the blue OK button. To delete a panel set: Follow the above procedure but set the MODE parameter to DELETE and press the blue OK button. Adding NOTES to PANEL and A-LOG sets: When storing panel calibration settings or waveforms, it is often useful to add some notes to the set so it can later be identified, or to help the user recall the correct set.
DFX-444 Operator’s Manual Issue 3 To select a character from the character map below the Notes lines, use the yellow UP/RT and DN/LT buttons to move the highlight through the map. The press the yellow OK button to add the character to the NOTES lines at the position of its cursor. As an alternative The Dakota Ultrasonics Keyboard may be used to enter NOTES as described in the Panel section 6.1.3. Once the desired notes have been added or edited, press the yellow button adjacent to the EXIT box.
DFX-444 6.4 Operator’s Manual Issue 3 Flaw Testing 6.4.1 Basic Flaw Testing Reliable flaw detection requires three important considerations: a) proper transducer/probe selection, b) an accurate reference block of the same material as that being tested with reference holes representing the orientation and sensitivity desired, and c) proper calibration of the instrument. The following are the basic guidelines for accurate flaw detection but the user is referred to Section 1.
DFX-444 Operator’s Manual Issue 3 fabricated discontinuities should match the expected natural discontinuities in the test piece. In some cases this may mean flat bottom holes perpendicular to the test surface, side drilled holes parallel to the testing surface, or in some cases, narrow notches representing planar surfaces parallel or perpendicular to the testing surface.
DFX-444 Operator’s Manual Issue 3 6.4.2 DAC Operation Distance Amplitude Correction curves act as monitoring gate triggering thresholds to compensate for attenuation and sound beam characteristics. When properly established, the DAC curve will provide consistent alarming from discontinuities of equal relative size at different depths in the test piece. Functionality is provided to automatically draw 6dB and 14dB or 6dB and 12dB reference curves below the calibrated curve.
DFX-444 Operator’s Manual Issue 3 5. Use the INC and DEC buttons to position the bright cursor bar over the echo from the reference hole. 6. Press the OK button to accept the point. A small square will appear as a reference point on the display showing the peak of the signal just recorded. 7. Repeat steps 5 and 6 for each additional reference hole in the reference block, being careful to be consistent with the amount of coupling and transducer/probe pressure.
DFX-444 Operator’s Manual Issue 3 9. Use the CURVE parameter and the INC button to select just the DAC reference curve, the DAC curve along with the -6dB and -12dB curves, or the DAC curve along with the -6dB and -14dB curves. These additional, automatically generated reference curves provide a means for evaluating discontinuities smaller than those in the reference block. 10. Use the TRIGGER parameter to establish the alarm trigger from the DAC curve, the -6dB curve, or the -12dB/-14dB curve.
DFX-444 Operator’s Manual Issue 3 Figure 123 – DAC Curve and -6dB/-14dB Curves 6.4.3 TCG Operation The Time Corrected Gain feature provides a means of creating an attenuation curve that sets the gain in a swept manner as a function of transit time. A properly constructed TCG curve will compensate for material attenuation and sound beam characteristics so that discontinuities of equal relative size at different depths in the test piece will give an equal amplitude response on the display.
DFX-444 Operator’s Manual Issue 3 To establish a TCG curve, follow the following instructions: 1. Establish the basic calibration of the DFX-444 using the desired transducer/probe and the proper reference block. 2. From the FN menu, select the TCG feature. 3. Select the MODE parameter by pressing the yellow button next to it and use the DEC button to select DRAW. The other parameters will now be CURSOR and POINT. 4. The TCG system is now ready to accept reference points.
DFX-444 Operator’s Manual Issue 3 8. Press the yellow button adjacent to MODE and use the DEC button to select ON mode. The TCG curve will now be displayed, the amplifier gain will now swept, and the other parameters will change to CURVE. Figure 134 – Equalization of Echoes Using TCG 9. Use the CURVE parameter and the INC button to select ON or OFF for the display of the TCG curve. NOTE: A TCG curve cannot be drawn while in RF display mode (DETECT-RF), but can be activated.
DFX-444 Operator’s Manual Issue 3 6.4.4 Weld Inspection Using Trigonometry Mode The Trigonometry Mode provides a convenient method for measuring the location of discontinuities when inspecting welds with angle beam transducers. Essentially, the trigonometry mode uses the thickness gauging features of the DFX-444 to calculate the surface distance and Figure 145 – Trigonometry Mode depth to a discontinuity Measurements from the actual beam path measured.
DFX-444 â Operator’s Manual Issue 3 Depth distance D from the surface on which the transducer/probe rests to the discontinuity. It is important to note that discontinuities in welds can be discontinuous and can extend over a distance. The measurements made will, therefore, be close approximations to the discontinuity if the user properly calibrates the DFX-444 and uses care to locate the desired peak amplitude signal to which a measurement is made.
DFX-444 Operator’s Manual Issue 3 7. Select the THICK parameter and using the INC and DEC buttons dial in the thickness of the test piece. You may have to readjust this parameter if the test piece had varying thickness Figure 156 – Trigonometry Mode Measurements and you are using a multiple skip mode of angle beam testing. 8. When measuring a discontinuity, position the transducer/probe so as to obtain the maximum amplitude signal before recording the readings.
DFX-444 Operator’s Manual Issue 3 6.4.5 Weld Inspection Using the AWS Menu The AWS menu (available on Models sold in certain countries where the AWS methods are used such as the United States, Canada and Mexico) provides a means for evaluating discontinuities when inspecting welds in accordance with the American Welding Society’s Structural Welding Code, ANSI/AWS D1.1-94. The user is referred to the AWS standard for full details of the method.
DFX-444 Operator’s Manual Issue 3 2. Ensure that the gate and measurement (TRIG) function are operative and properly adjusted. 3. When the AWS menu is selected and a signal is in the gate, the sub-menu boxes will show the resulting AWS measurements as follows: IR = IL – RG - AF (Indication Rating = Indication level – Reference Gain – Attenuation Factor) Where: IL: Indication Level is the dB setting required to bring an indication to the reference level.
DFX-444 Operator’s Manual Issue 3 6.4.6 A-LOG, A-Scan Storage The A-LOG feature provides for storage, recall and printing of A-Scans with all of the instrument settings. Up to 100 A-Scans and their settings can be stored. This feature is useful to record an indication for later review or for printing a hardcopy. In addition, recalling an A-Scan and its settings will allow for easy follow-up inspection of the same indication on the test piece.
DFX-444 Operator’s Manual Issue 3 FZ/PK button twice to activate the Peak mode, which is indicated, 7. Press the OK button to store the waveform and instrument settings. At the CONFIRM prompt, press the OK button again to store the A-Scan or press the INC button to continue without storing the A-Scan. 8. After pressing the OK button a second time, the NOTES window opens automatically to allow the creation of any desired notes for the stored A-Scan and its settings.
DFX-444 Operator’s Manual Issue 3 To delete a stored A-Scan, follow the steps above but set the MODE parameter to DELETE and then press the OK button. At the CONFIRM prompt, press the OK button again to delete the A-Scan or press the INC button to continue without deleting the A-Scan. To edit notes in an A-LOG, press the yellow button next to the EDIT NOTES parameter and then follow the instructions in the section on Adding NOTES to PANEL and A-LOG sets on page 58.
DFX-444 Operator’s Manual Issue 3 compared to the real time waveform, depending on which color is chosen. 6. To remove the reference waveform, set the MODE to OFF and press the OK button. NOTE: When the reference is recalled, no setting parameters are changed. Therefore, if the RANGE or DELAY are subsequently changed, the reference signal will not match the real time waveform.
DFX-444 Operator’s Manual Issue 3 moving forward past the indication. This will assure the capturing of all amplitude and distance information. An example of peak echo mode capture is shown in Figure 16. To return the display to normal mode, press the FZ/PK button a third time. This will erase the envelope pattern and return the Figure 167 – Peak Echo Dynamics instrument to the instantaneous mode of display.
DFX-444 6.5 6.5.1 Operator’s Manual Issue 3 Thickness Gauging Basic Thickness Gauging Accurate and reliable thickness gauging requires three important considerations: a) proper transducer/probe selection, b) an accurate reference block of the same material as that being tested, and c) proper calibration of the instrument. The following are the basic guidelines for accurate thickness gauging but the user is referred to Section 1.3 on Operator Training for advice on seeking in-depth training.
DFX-444 Operator’s Manual Figure 18 – Broadband Echo Issue 3 Figure 19 – Narrowband Echo The next requirement for thickness gauging is a calibration or reference block. This block should be made of the same material as the components to be inspected. In other words, it should have the same sound velocity and attenuation characteristics. The calibration block should have parallel machined surfaces representing the thickness range to be inspected.
DFX-444 Operator’s Manual Issue 3 Finally, it is necessary to establish the proper calibration of the DFX-444 in order to assure accurate and reliable thickness testing. The essence of this calibration is to set the pulser and amplifier characteristics to provide sharp leading edges on the echoes. The following are the essential steps for basic thickness gauging: 1. Select the appropriate broadband transducer/probe and calibration block that matches the material under test. 2.
DFX-444 Operator’s Manual Issue 3 10. If desired, set the T-Min parameter to ON so that the thinnest reading obtained will be held in the display. Reset by using the INC or DEC buttons. 11. If desired, set the HUD parameter to ON to display the thickness in a large window at the top right of the graticule. 12. To calibrate the DFX-444 for thickness readings, follow the steps outlined in Section 6.5.2 below.
DFX-444 Operator’s Manual Issue 3 with the interface or first echo from terminating the measurement and producing a false reading. For storage and printing of thickness readings, refer to Section 6.5.4 on page 84 and Section 6.5.6, T-FN Thickness Log Editing and Printing on page 88. 6.5.2 A-Cal A-CAL is an automated calibration feature for thickness gauging applications or when measuring depth to an indication in flaw testing.
DFX-444 Operator’s Manual Issue 3 between the thick sample and the thin sample should be no less than five to one. 2. From the Main menu, select CAL and adjust the RANGE and DELAY so that the thin and thick reference echoes show on the display. 3. From the Main menu, select GATE1 and place the STATE in ON +VE. Adjust the START and WIDTH of the gate to encompass the echoes from the thin and thick samples. 4. From the Main menu, select MEAS and place the MODE to DEPTH. 5.
DFX-444 Operator’s Manual Issue 3 time a calibration is desired. Once established, all that is required is to obtain each echo and press OK, and then press OK on ACCEPT CAL and the instrument is calibrated. If a delay transducer/probe is used set DIST1 to 0.0 and use the interface echo as the thin reference echo. The instrument will then set the transducer/probe zero to compensate for the delay line.
DFX-444 Operator’s Manual Issue 3 the LOCation number which can be set between 1 and 2,000. Last is the reading number (NO) itself which can also be between 1 and 2,000. This hierarchy of coding for a thickness reading allows readings to be associated with physical characteristics of the component under inspection. Thus, it is up to the user to devise a scheme of assigning blocks, locations and readings to the inspection, keeping in mind the maximum combination of 2,000.
DFX-444 Operator’s Manual Issue 3 used to guide the operator when collecting thickness readings. The collected readings could then be uploaded to the computer for further analysis and storage, releasing the DFX-444 to collect readings from another component. When a component is reinspected, the historical readings can be downloaded to the DFX444, providing the operator with an instant check of thickness variation while collecting new readings.
DFX-444 Operator’s Manual Issue 3 Once selected, the graticule will reduce in size and a window is drawn on the top left of the screen next to the HUD window which is automatically switched on. The location and thickness data will be shown in the window if any data has been downloaded to the DFX-444. Alternately, the Sequence mode can be turned on by a command from the host computer. 3. Set up the instrument for the thickness measuring mode as described in Section 6.5.1 on page 78. 4.
DFX-444 Operator’s Manual Issue 3 9. Once all of the readings for a component have been taken, they can be uploaded to the computer for further analysis and storage. The location data transferred is the 32 character string associated with the location, the thickness value, the units of measure, and the notes. Locations with a blank note will contain the characters “OK.” 6.5.
DFX-444 Operator’s Manual Issue 3 2. Select the T-FN menu from the MEMORY menu. 3. Select the MODE parameter by pressing the yellow button next to it and pressing the INC button to select PRINT mode. 4. Select the desired Block number by pressing the yellow button next to the BLOCK parameter and using the INC or DEC buttons. 5. Set the Location number to ALL by pressing the yellow button next to the LOC parameter and using the DEC button if not already selected. 6.
DFX-444 Operator’s Manual Issue 3 7. Power Supply The DFX-444 is powered by a Lithium-Ion battery pack, which is shown in Figure 17 below. The power box attaches to the rear of the DFX-444 with two thumbscrews and connects to the instrument via two terminal contact points. Figure 170 – Lithium-Ion Battery Box 7.1 Lithium-Ion Battery Pack When fully charged, the battery pack should enable the unit to be operated for 8 hours, (Significantly longer with the LCD display) under typical operating conditions.
DFX-444 Operator’s Manual Issue 3 connector on the front panel. Alternately, the battery pack can be charged separate from the DFX-444 by using its own connector shown in Figure 17 above thereby allowing continued operation of the DFX-444 with the use of multiple battery packs. 7.2 Battery Charging The Dakota Ultrasonics CH700 battery charger shown in Figure 18 below is suitable for use with main supply from 100 to 240 volts AC. The LED on the charger illuminates to indicate power on.
DFX-444 Operator’s Manual Issue 3 8. Interface Connections The various interface connections are provided in a sealed compartment under a spring-loaded door at the rear of the DFX-444. The connections are shown in Figure 19 below and described in the following.
DFX-444 8.1 Operator’s Manual Issue 3 RS232 The RS232 port on the DFX-444 allows for bi-directional communication between the instrument and a personal computer. Various control commands are available within three general categories; Write parameter values, Read parameter values, and Action commands. The Write and Read parameters allow the computer to set a parameter and to read parameters current value. The Action commands provide special functions such as waveform and thickness logging transfer.
DFX-444 Operator’s Manual Issue 3 The cable connections for a 25-pin RS232 port are as follows: SS240 NC PIN 1 PIN 1 PC NC RD TD DTR GND DSR 2 3 4 5 6 3 2 20 7 6 RD TD DTR GND DSR NC CTS NC 7 8 9 5 25 NC CTS NC A 9-pin to 9-pin communications cable is available from Dakota Ultrasonics Plc under part number 152120. No cable is available for the 25-pin RS232 port. A separate Communications manual part number 147239 is available that describes all of the protocol in detail. 8.
DFX-444 Operator’s Manual Issue 3 8.3 Proportional Output An analog proportional output 0 to 10 volts dc, for distance and amplitude of the signal in the gate.
DFX-444 Operator’s Manual Issue 3 9. Specifications Test Range: 5mm to 20,000mm (0.25-800in) at steel velocity. Variable in 1,2,5, sequence, or continuously in 1mm (0.05in) increments. Velocity: 1000m/s to 9999m/s continuously variable. Probe Zero: 0 to 999.999µs, continuously variable. Delay: Calibrated delay from 0mm to l0,000mm in 0.05mm steps at steel velocity (0-400in. in 0.002in steps). Gain: 0 to 110dB. Adjustable in 0.5, 2, 6, 14 and 20dB steps.
DFX-444 Operator’s Manual Issue 3 System Linearity: Vertical ±1% Full Screen Height (FSH). Amplifier accuracy ±0.1dB. Horizontal ±0.4% Full Screen Width (FSW). Reject: 50% suppressive reject. LED warning light when selected. Units: Metric (mm), inches (in) or microseconds. Selected from menu. Display: Color: High brightness Color TFT LCD panel. Eight (8) Color scheme options. Brightness variable up to 350cd/m2 LCD: monochrome Liquid crystal display, with switchable backlight.
DFX-444 Measurement Modes: Operator’s Manual Issue 3 Mode 1 - Signal monitor. Mode 2 - Depth and amplitude of first signal in gate. Mode 3- T-Min mode for holding minimum thickness reading. Mode 4 - Echo-to-echo distance measurement. Mode 5 – Trigonometric display of beam path, surface distance and depth of indication. Mode 6 - Gate to Gate Resolution to 0.01mm (0.001in) for distance measurement, or 1% FSH for amplitude measurement. Large display of measurement at top of A-Scan display.
DFX-444 Thickness Logging: Operator’s Manual Issue 3 Storage for 2,000 thickness readings configured into Block/Location/Number. Calibration settings stored with each Block. Maximum number of Blocks is 14. Unlimited Location/Number values, maximum combination of 2,000 readings. Readings may be reviewed, edited and printed as required. Auto-Cal: Provides automatic calibration from two echoes. DAC: DAC curves may be entered and digitally drawn on the display.
DFX-444 Operator’s Manual Issue 3 Reference Waveform: This menu displays a waveform from one of the A-Log stores as a reference or fingerprint in a Color different from the active display highlighting differences from the reference. Notes: Alphanumeric-labeling for panel and A-Log allows the user to enter Notes for storage with A-Scans. X-Offset: Allows the surface distance to be calculated from the front of the probe with X-offset being the distance from the index point to the front of the probe.
DFX-444 Power Operator’s Manual Issue 3 Lithium-Ion sealed battery pack, Typically 8 hours operation on color display model at medium display brightness, more on LCD. On-screen indication of battery status. Charger: Universal mains input 85-260 volts AC Probe Sockets: BNC or LEMO (factory option) Temperature: Operating: Survivable: Storage: Environment: To IP67 Size: 255 x 145 x 145mm (10.0 x 5.7 x 5.7in) Weight: 2.5 Kgs (5.5 lbs.) with Li-ION Cells.
DFX-444 10. Operator’s Manual Issue 3 Warranty Warranty/Defects after Delivery: Immediately upon receipt of the goods the buyer is required to check the goods carefully and thoroughly. In order to benefit from the guarantee, any defect in the product should be immediately reported in writing to Dakota Ultrasonics.
DFX-444 Operator’s Manual Issue 3 Index Broad Band · 7 Button · 6, 20, 21, 22, 23, 24, 25, 26, 28, 29, 30, 33, 36, 37, 38, 39, 41, 45, 48, 51, 56, 57, 58, 59, 62, 63, 64, 66, 67, 69, 70, 73, 74, 75, 76, 77, 81, 83, 85, 86, 87, 88, 89 Buyer · 102 A A-CAL · 37, 54, 69, 82, 83 Acoustic · 9 Acoustic Impedance · 9 Alarm Outputs · 99 A-LOG · 47, 48, 49, 50, 55, 58, 59, 73, 74, 75, 76, 83 American Society of Nondestructive Testing · 2 American Welding Society · 2, 40, 71, 99 Amplifier · 7, 97 AMPlifier Menu ·
DFX-444 Operator’s Manual Issue 3 CURVE · 38, 39, 40, 54, 63, 64, 67 F D Factory default · 25 Far Field · 11 Far Surface · 9, 60 FLANK · 27, 28, 33, 43, 80 Flaw Detection · 3, 8, 26 Flaw Detector · 1, 2, 6, 7 Focal Length · 18, 19 Focus · 11, 14, 18 Freeze · 7, 23, 74 FREQ · 31, 54 Frequency · 2, 9, 10, 11, 12, 13, 14, 31, 60 Front Panel Controls · 20, 29 Front Surface · 4, 10, 15, 60 Function · 23, 27, 30, 37, 56 Function Menu · 37 FW · 31, 61 FZ/PK · 23, 49, 50, 58, 73, 74, 76, 77 DAC · 7, 25, 27,
DFX-444 Operator’s Manual Issue 3 MODE · 27, 28, 33, 34, 35, 38, 39, 40, 43, 44, 45, 49, 50, 53, 54, 55, 56, 58, 62, 63, 64, 66, 67, 69, 71, 73, 74, 75, 76, 83, 86, 88, 89 Mode Conversion · 2, 16 Multiple Echo · 81 I IIW · 69 Immersion · 8, 18, 19 Immersion Testing · 18 Impedance · 9 Inches · 26, 27, 30, 32, 72, 97 Incident Angle · 16, 17 Included Angle · 14, 78 Inclusions · 9 Interface Connections · 92 N Near Field · 3, 11, 12, 18 NiCd · 90 Nondestructive · 6, 10 Nondestructive Inspection · 10 Notes ·
DFX-444 Operator’s Manual Pitting · 14, 78 Planar · 10, 61 POINT · 38, 39, 40, 54, 62, 66 Porosity · 9, 17 Power Supply · 24, 90 PRF · 25, 31 PRINT Menu · 36 Printing · 36, 53, 61, 73, 82, 86, 88, 89 Probe · 3, 4, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 22, 24, 26, 27, 30, 31, 34, 37, 38, 56, 60, 61, 62, 63, 66, 68, 69, 70, 71, 72, 73, 76, 78, 79, 80, 81, 82, 83, 84 Probe Calibration · 3 Probe Pressure · 62, 63, 66 Probe Zero · 3, 22, 37, 79, 83, 84, 96 Pulse · 96 Pulse Repetition Frequency · 31 Pul
DFX-444 Operator’s Manual Temperature Variations · 4 Test Blocks · 3, 4 Testing Limitations · 2 T-FN Menu · 53 Thickness Gauge · 1, 7 Threshold · 32, 33, 34, 38, 62, 84 Time Corrected Gain · 10, 39, 62, 65, 84, 99 Time Of Flight · 2 Time-Of-Flight · 9, 82 T-LOG · 51, 55, 84, 85, 87, 88 T-LOG Menu · 51 T-MIN · 27, 29, 33, 54 training · 1, 2, 6, 17, 60, 78 Transmit-Receive · 8 TRIGGER · 27, 28, 33, 38, 43, 53, 54, 55, 64, 69 Trigonometric · 7, 98 Twin · 24 TX · iii Issue 3 V VALID · 45, 49, 50, 56, 73, 74
