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EPOCH LT

1. difference between the electric zero English Int Color Function FILTER FILTER Orange Pulser Press this key multiple times to toggle through the pulser parameters itera Use the function keys to select preset values for each pulser parameter White Peak Memory Function Activates the Peak Memory function allowing continuous accumulation of peak FILTER FILTER envelope data with the live waveform PEER Orange Press this key again to deactivate the function Orange Display View Press this key multiple z s 7 times to toggle between Full Screen pase ay LAA View full A Scan display and Split l Screen View half sized A Scan with l setup parameters Se zr Orange Depth Amplitude Allows z selection and display of peak depth DEPTH he Z ANP Nz edge depth signal amplitude or time of flight data White Echo to Echo Measurement Activates the Echo to Echo Measurement mode This ECHO ECHO ALA automatically opens Gate 2 if it is not pay Ne Orange already active and allows you to select edge to edge or peak to peak measurement using the function keys CONTRAST a Yellow Auto Calibration Initiates the EPOCH LT Auto Calibration feature in CAL CAL conjunction with the ZERO OFFSET and VELOCITY keys White Contrast Adjustment Adjusts the contrast and backlight for units with a Liquid Crystal Display LCD CONTRAST a CAL CAL Yellow DIV Yellow Zero Offset Compensates for the time 9 1 Q
2. Probe Another name for a transducer or search unit Pulse Repetition Rate The frequency with which the clock circuit sends its trigger pulses to the sweep generator and the transmitter usually quoted in terms of pulses per second pps Range The distance represented by the entire horizontal CRT screen display Receiver That circuit of a flaw detector that receives both the initial pulse voltage from the transmitter and the returning echoes as voltages from the transducer By passing these incoming signals through certain subcircuits the signals are rectified filtered and amplified with the results sent to the screen for display Reference Echo The echo from a reference reflector Reference Level The number of decibels of calibrated gain that must be set on the instrument to bring the reference reflector signal to peak at the reference line on the screen 101 EPOCH LT 102 Term Definition Reference Line A predetermined horizontal line usually dictated by specifications on the screen representing some percentage of total screen height for example 40 at which reference echoes and indication echoes are compared Reference Reflector A reflector of known size geometry at a known distance such as a flat bottom hole Refraction Angle of The angle of sound reflection in the wedge equal to the angle of incidence also in the wedge The angle of reflectance is meas
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4. 6 Position Gate 1 over the desired echo to begin drawing the DAC curve Adjust the gate level if necessary to make sure the echo breaks the gate Press F1 7 Move Gate 1 to the appropriate position to capture the next point for the curve 8 Press F1 Repeat this step until all points for the curve are captured 9 Press F2 to complete the curve once the last point is captured Part 910 258 Using Software Options Tip To correct a mistake made while drawing the curve press F3 to clear the curve and start again FLAWCHK3 85 gt LOC1E GAIN 37 8dB RANGE 8 588in 4 200 ID SELECTED MIN DEPTH 8 197 EEEE GA A Figure 40 Creating a DAC Curve When the DAC mode is active any parameter that would affect instrument calibration is automatically locked This includes GAIN RANGE ZERO OFFSET VELOCITY ANGLE REJECT and all pulser and filter parameters To obtain amplitude information in the DAC mode press DEPTH AMP and F3 If you highlight the DAC selection in the DAC setup screen the EPOCH LT displays the current echo height percentage in terms of full screen height and the percentage of the echo related to the primary DAC curve level If DB DAC is selected the current echo height percentage in terms of full screen height and the dB value of the echo related to the primary DAC curve level are displayed Once the curve is complete the Reference Gain functi
5. Setting up Parameters Managing Basic Operations The EPOCH LT Setup screen allows you to select basic system parameters To access the Setup screen press OPTION Move the highlight bar over Setup and press ENTER The following screen appears RF EDIT PARAMETR DGS AWS D1 1 ECHO ECHO EXT RANGE EXPANDED MEN OPTION EXI Fad ANGLE 96 6 THICK 8 808 in PU bHTE START WIDTH 1 B 388 B077 i 1 748 8 583 BEEP ON GRID OFF ALL LOCK CAL LOCK LIWE FILLED PEAK FILLED Us ALKALINE BAT ij i LSE ECHO LEVEL io a JJ g Menu Options ALARN OFF OFF The selections in the Setup menu are grouped according to function Use the green slewing keys to move around this menu Press ENTER to select deselect an item Press OPTION to return to the live screen after making choices Description When this symbol appears after a menu item it means that another menu is available Highlight the item using the slewing keys and press ENTER to view the next menu When this symbol appears after a menu item it means that multiple items within the group can be selected item is selected When this symbol appears after a menu item it means that the 3 6 Figure 9 Symbol gt Table 4 3 6 1 Menu Symbol Descriptions Language Selection You can use the EPOCH LT in any of the following languages Part 910 258 33 EPOCH LT 3 6 2 3 6 3 3 6 4 34 e
6. IA pe point the time when the pulse is first generated and the acoustic zero point the time when the sound energy enters the test material Table 3 Keypad Functions Continued Managing Basic Operations ANGLE English Int Color Function White Div Graticule Display Displays the grid numbers along the bottom of the EPOCH LT display in Full Screen DIV DIV mode These numbers are sometimes JERO 2 Yellow blocked by the function key presets OFFSET J 200M ro Yellow Range Sets the amount of sound travel ER time that is viewed on the display in i AAS units of material travel distance Use the function keys to select preset values and the slewing keys to fine tune this setting White Zoom Expands the screen area covered by Gate 1 to full screen width for higher resolution viewing of ZOOM oe portions of the waveform Yellow REJECT Yellow Velocity Sets the velocity of sound in a test material for distance calculations Use the function keys to select preset values and the slewing keys to fine tune this setting White Reject Removes low level noise and or signal from the waveform being viewed on the display Use the function REJECT Sot keys to select preset values and the Yellow slewing keys to fine tune this setting THICKNESS TE Yellow Angle Allows the entr
7. The smaller length if rectangular of the actual crystal The software will compute the affective length automatically Immersion Testing A test method useful for testing irregularly shaped parts in which the part to be tested is immersed in water or other liquid so that the liquid acts as a couplant The search unit is also immersed in the liquid but not in contact with the part being tested Incidence Angle of The angle between a sound beam striking an acoustic interface and the normal that is perpendicular surface at that point Usually designated by the Greek symbol o alpha Indication The signal displayed on the screen signifying the presence of a sound wave reflector in the part being tested Indication Defect Level The number of decibels of calibrated gain that must be set on the instrument to bring the indication defect echo signal to peak at the reference line on the screen Initial Pulse IP The pulse of electrical energy sent by the pulser to the transducer Leg In angle beam testing the path the shear wave travels in a straight line before being reflected by the opposite surface of the material being tested Linearity Vertical or Amplitude The characteristics of an ultrasonic test system indicating its ability to respond in a proportional manner to a range of echo amplitudes produced by specified reflectors Linearity Horizontal or Distance The char
8. 3 8 mm of metal path If the first detected echo breaks Gate 1 at 0 35 8 9 mm then Gate 2 Start automatically adjusts by the value of the blanking period to 0 50 0 35 0 15 or 12 7 mm 8 9 mm 3 8 mm There is a trade off in defining the blanking period While a relatively long period may prevent false readings the minimum measurable thickness is limited to a value slightly greater than the blanking period eae os Ne hee eens Se J CER ERCEEMRANGE 2 000in 1 142 MIN DEPTH 1 141 in 190 4 4 h ga 68 Figure 42 Set up for Peak to Peak Measurement Extended Range The standard EPOCH LT has a range of 0 16 to 200 00 4 mm to 5 000 mm With the Extended Range option the instrument range is increased to 0 038 to 400 00 1 mm to 10 000 mm Extended Range is a factory installed software option Once this option is activated you cannot turn it on and off To verify that an EPOCH LT is equipped with Extended Range press the OPTION key If the square next to the Extended Range option is filled i then the instrument is equipped with this option if the square is empty D then the instrument is not equipped with this option Curved Surface Correction The Curved Surface Correction CSC option for the EPOCH LT is used to provide accurate sound path values when inspecting curved surfaces such as pipes When you enter the pipe diameter and thickness soundpath information is adj
9. USER S MANUAL EPOCH LT Part No 910 258 F PANAMETRICS NDT Nondestructive Testing Products In accordance with European Directive 2002 96 EC on Waste Electrical and Electronic Equipment this symbol indicates that the product must not be disposed of as unsorted municipal waste but should be col lected separately Refer to your local Olympus distributor for return and or collection systems available in your country Copyright 2005 by Oylmpus NDT All rights reserved No part of this manual may be reproduced or transmitted in any form or by any means electronic or mechanical including photocopying recording or by any information storage and retrieval system without the written permission of Oylmpus NDT except where permitted by law For information contact pana OylmpusNDT com Panametrics Panametrics NDT and the Panametrics NDT logo are trademarks of Panametrics Inc Other product names mentioned in this document may be trademarks of their respective companies and are mentioned for identification purposes only Printed in the United States of America Warranty Part 910 258 Warranty The EPOCH LT Digital Ultrasonic Flaw Detector has been designed and manufactured as a high quality instrument Under normal working conditions the EPOCH LT will provide long trouble free service Damage in transit Inspect the unit thoroughly upon receipt for evidence of external or internal damage that may ha
10. hj TVG DAC PRF AWS CSC DGS CAL E NNW AW l Indicates the EPOCH LT is in the optional Echo to Echo Edge Measurement mode and the measurement is being made between the leading edges of the two selected signals Indicates the Peak Memory function is active Indicates the display is frozen because the Freeze function is active Indicates the Zoom function is active to expand the region within the flaw gate to full screen width Indicates the gate alarm is tripped Indicates Time Varied Gain is active Indicates Distance Amplitude Correction is active Indicates Low PRF Pulse Repetition Frequency is active Indicates AWS American Welding Society Structural Welding Code software option is active Indicates CSC Curved Surface Correction option is active Indicates DGS Distance Gain Sizing option is active Indicates Calibration is active Indicates the All Lock function is active meaning all keys are locked except DISPLAY OPTION ENTER A lt 4 gt and ON OFF Indicates the Cal Lock function is active meaning you cannot use the following keys GAIN VEL REJECT CAL ANGLE THICKNESS ZERO OFFSET PULSER FILTER and RANGE Indicates the soundpath leg in which a particular reflector is located Ist 2nd 3rd 4th and beyond 4th Indicates the remaining battery life in the unit The battery level is constantly displayed in the lower right corner of the display
11. Calibrating with a Delay Line Transducer The sample delay line calibration described below is performed using Panametrics NDT transducer part number V202 RM with a frequency of 10 0 MHz and an element diameter of 0 25 6 mm The calibration requires a test block with two known thicknesses made from the material to be measured Ideally the two thicknesses measurements are both below and above the expected thickness of the material to be inspected For this example we are using a Panametrics NDT standard 5 step steel test block part number 2211E The steps measure 0 100 0 200 0 300 0 400 and 0 500 Note If the EPOCH LT is set to work in metric units the calibration process is exactly the same except that the entries below will be in millimeters rather than inches To calibrate using a Delay Line transducer follow these steps 1 Follow the initial set up procedure outlined in Section 7 1 Connect the transducer to an appropriate cable and then connect the cable to either of the transducer posts on the EPOCH LT With a Zero Offset of 0 000 us the Main Bang or excitation pulse should appear on the left side of the screen Increase the Zero Offset until the Main Bang moves off the left side of the screen and the interface echo from the end of the delay line tip appears on the screen Verify that the echo represents the end of the delay by tapping your finger on the end of the couplant coated delay line This dampens t
12. F1 key when you have finished editing the parameters to save the settings and return to the Options menu When you select one of the parameters that you edited the new preset values appear above the F keys 28 3 5 3 5 1 Part 910 258 Managing Basic Operations 2 4 8 18 3127 m s FULLWAVE DATE 09 17 04 ZERO 10 09 us ENERGY LOW TIME 16 53 ANGLE 45 8 DAMP 5 DELAY 4 888 tm 8 68 mm PULSE ECHO START WIDTH LEVEL ALARM 71 863 72 198 37 2 OFF 216 73 7 817 OFF OFF 15 HdB 25 8dB 35 8dB 45 806 Figure6 Viewing New Preset Values Managing the Display The EPOCH LT can present the A Scan in two different display formats split screen and full screen A split screen presents simultaneous viewing of the waveform and all instrument set up data The full screen presents a large high resolution waveform and important basic information Note After the EPOCH LT is powered up and completes the self test routine the split screen opens To set the display parameter press DISPLAY to switch to full screen or press DISPLAY again to switch back to the split screen Full Screen A Scan Display The full screen A Scan presents a large high resolution waveform and some basic data to aid with interpretation of the display 29 EPOCH LT 3 5 2 30 SNARE GE 7 300 4 270 MIN DEPTH 8 in 1887 i 89 Figure7 Full Screen Display Top of the screen e The Filename Gain level ID Co
13. The point in time when the pulser fires the initial pulse to the transducer and the point on the cathode ray tube screen where the electron beam leaves the baseline due to the initial pulse signal coming from the transmitter First Critical Angle The minimum incident angle in the first medium at which the refracted longitudinal wave is eliminated from the test specimen Flaw A discontinuity that may be undesirable but does not necessarily call for rejection Frequency The number of complete cycles undergone or produced by an oscillating body in one second Gain Used in electronics with reference to an increase in signal power usually expressed as the ratio of the output power for example of an amplifier to the input power in decibels Gain Control Selects the amount of calibrated gain dBs available within the instrument Usually consists of a coarse gain control additions at 20 dB increments and a fine gain additions at 1 or 2 dB increments Gate An electronic baseline display used to monitor portions of the displayed range with reference to distance or amplitude 99 EPOCH LT 100 Term Definition Hertz The derived unit of frequency defined as the frequency of a periodic phenomenon of which the period is one second equal to one cycle per second Symbol Hz 1 Kilohertz KHz 10 cycles per second 1 Megahertz Mhz 10 cycles per second Horizontal A
14. sample ENTER VALUE FOR THIN STANDARD 000 10 Figure 26 Entering a Thin Standard Value 6 Press CAL The display returns to the live A Scan Couple the transducer to the THICK calibration block step For this example the transducer is coupled to the 0 500 step Position Gate 1 so that the leading edge of the backwall echo from the known thickness step is exceeding the gate threshold A thickness reading appears in large text above the A Scan 63 EPOCH LT 7 5 64 gt RANGE 1 688in MIN DEPTH 4 6 8 10 VEL 2328infus FULLWAVE DATE 89 18 84 ZERO 3 437 us ENERGY MED TIME 09 17 ANGLE 4 8 DAMP S DELAY 4 688 in THICK 6 6668 in DUAL GATE START WIDTH LEVEL ALARM 1 0 071 8 786 43 2 2 16 081 6 588 OFF 10 8dB CAL Figure 27 Calibrating for a Thick Block Using a Dual Element Transducer 8 Press WEL once the reading is steady The screen freezes and a pop up box appears again on the screen Use the 4 and slewing keys to enter the exact known thickness of the test sample ENTER VALUE FOR THICK STANDARD 000 50 Figure 28 Entering a Thick Standard Value 9 Press ENTER to complete the Auto Calibration The Zero Offset and Velocity parameters adjust automatically and the correct thickness reading of any gated echo is displayed on the screen Calibrating with an Angle Beam Transducer The sample angle beam calibration described below is performed using Panametrics NDT
15. transducer part number A420S SB with a frequency of 2 25 MHz and an element diameter of 0 625 x 0 625 The transducer is mounted on a 45 wedge part number ABWS 6 45 We recommend using either an ASTM E 164 IIW Type Ior a U S Air Force IW Type II Calibration Block for this procedure The steps below use a Panametrics NDT IIW Type I carbon steel calibration block part number TB7541 1 To calibrate using an Angle Beam transducer follow these steps 1 Follow the initial set up procedure outlined in Section 7 1 7 5 1 Part 910 258 Calibrating the EPOCH LT Connect the transducer to an appropriate cable and then connect the cable to either of the transducer posts on the EPOCH LT 2 Enter the correct refracted angle for the transducer wedge combination For this example enter 45 3 Enter the approximate shear wave velocity of the material being inspected For this example using carbon steel enter a velocity of 0 1280 in us 3251 mm us if working in metric units 4 Enter an appropriate range for the test block being used For this example enter a range of 10 000 250 00 mm if working in metric units See sections 7 5 1 7 5 4 for the following procedures e Locating the Beam Index Point B I P of the probe e Verifying the Refracted Angle Beta e Calibrating for Distance e Calibrating for Sensitivity Note If the EPOCH LT is set to work in metric units in each procedure listed above the calibration proce
16. 84 9 7 Extended Rante nn ioo i aae sake ied EERTE es HERA Ae E ER 85 9 3 Curved S rface Correction s iseen a E eh RE EE O 85 9 9 AWS DLI DIS o oriei aE Hea yey EA LGA EE ARR A NEDA 86 9 9 1 AWS D1 1 and the EPOCH LT nosnnananaaaaaa anra 87 9 9 2 Operating the AWS D1 1 Software 0 0 0 0 eee eee 87 9 9 3 Adding Scanning Gain 26 644 nc eids 2a be eee OER PRE ROR 88 9 94 Calculating A and C Values 0 0 cee eee eee 89 Appendix A Specifications 0 cece cece cen cece cnc ce eee eeeecsecsees 91 Appendix B Sound Velocities cc ccc ccc cece ccc cceccnccsscesceees 95 Appendix C Glossary 93s oe Se 65 39 eS 4 Fo eS C5 Oe OSH POR SG Ea E 97 Appendix D Parts List iiss d6 ess oes wo 6 es ee de vse RE Bee RRO a eiis 105 Documentation Comments 910 258 EPOCH LT 1 1 1 2 Part 910 258 Preface Preface This preface discusses the following introductory topics e Product Description e About This Document e Audience e Scope e Typographic Conventions e Related Documentation e If You Have Documentation Comments e Revision History e Technical Help Product Description The EPOCH LT is the smallest and lightest flaw detector ever offered by Panametrics NDT a Business of R D Tech Instruments Inc At only 2 35 pounds 1 0 kg and 1 5 inches 38 mm thick the EPOCH LT offers class leading size and weight along with the performance ofa fully featured flaw de
17. Displaying the D Value Pressing the SAVE WAVE key saves the data for this discontinuity in the EPOCH LT datalogger Note While using the EPOCH LT and the AWS D1 1 software option you must be aware of any inspection conditions that may cause variation in the displayed Indication Rating D value You must also be able to interpret the meaning of echo indications and reported D values corresponding to these indications properly Part 910 258 89 EPOCH LT 90 Appendix A Specifications Part 910 258 DISPLAY GRATICULE DISPLAY UPDATE RATE SENSITIVITY SELF CALIBRATION AUTO CALIBRATION REJECT UNITS MATERIAL VELOCITY ZERO OFFSET RANGE DISTANCE READOUT REFRACTED ANGLE GATE START GATE WIDTH GATE LEVEL Appendix A Specifications 320 pixels W x 240 pixels H Liquid Crystal Display LCD Split screen allows simultaneous viewing of waveform and setup data Selectable filled or outline waveform trace Electronically generated 2 625 x 2 375 67 x 60 mm No parallax error No changes in brightness due to repetition rate changes Minimum 60 Hz under all test conditions 100 0 dB max and reference level sensitivity feature with 6 dB or 0 1 dB selectable resolution Continuous automatic self calibration compensates pulse amplitude and receiver sensitivity for temperature and aging effects Automatic calibration of Zero Offset and or Velocity Absolutely linear
18. English e French e German e Japanese e Spanish e Italian e Russian Note The Custom option is not active To select or change a language to use on the EPOCH LT follow these steps 1 Move the highlight bar over the Language option and press ENTER 2 Move the highlighted bar over the desired choice and press ENTER 3 Press OPTION to exit Units of Measurement The EPOCH LT is capable of displaying and calculating distance parameters and soundpath data in terms of distance inches or millimeters or time microseconds When displaying in terms of distance the screen can be set to be viewed either in units per division for example 1 000 in div or 25 00 mm div or units full scale for example 10 00 in full scale or 250 mm full scale Units full scale describes the distance over the entire screen range When displaying in terms of time all distance parameters range zero offset gate position material thickness minimum depth and all soundpath data are displayed using microseconds us instead of inches or millimeters To change the units of measure follow these steps 1 Move the highlight bar over Unit and press ENTER 2 Use the slewing keys to select the desired unit setting and press ENTER 3 Press OPTION to exit Beep On Note When Beep On is selected pressing the keypad results in audible beeps Grid On Off When you select Grid Off only the borders of the graticule shows behind the wavefor
19. The customer will pay shipping expense to the Olympus NDT plant for warranty repair Olympus NDT will pay for the return of the repaired equipment For instruments not under warranty the customer will pay shipping expenses both ways In this manual we have attempted to teach the proper operation of the EPOCH LT consistent with accepted flaw detection techniques We believe the procedures and examples given are accurate However the information contained herein is intended solely as a teaching aid and should not be used in any particular application without independent testing and or verification by the operator or the supervisor Such independent verification of procedures become more important as the criticality of the application increases For these reasons we make no warranty expressed or implied that the techniques examples or procedures described herein are consistent with industry standards nor that they will meet the requirements of any particular application Olympus NDT expressly disclaims all implied warranties of merchantability and of fitness for any particular application Olympus NDT reserves the right to modify all products without incurring the responsibility for modifying previously manufactured products Olympus NDT does not assume any liability for the results of particular installations as these circumstances are not within our control THE WARRANTIES SET FORTH HEREIN ARE EXCLUSIVE AND ARE IN LIEU OF ALL OTHER WARR
20. Topics are as follows Powering up Using the Keypad Summarizing Keypad Functions Editable Parameters Software Managing the Display Setting up Parameters Powering up Pressing ON OFF causes an initial beep from the unit and then a series of relay clicks The display lights up and the unit goes through a self test for five 5 seconds Note You can do a Master Reset on the EPOCH LT during power up Press and hold the ANGLE key and then power the unit on Do not release the ANGLE key until the screen lights up with a Master Reset prompt box Press OPTION to cancel master reset and the unit will proceed to the live screen Otherwise press ENTER to continue Use the slewing keys to move the highlight bar over the desired selection Parameters Resets the unit s parameters back to the factor settings Database Erases the EPOCH LT s memory saved calibrations etc Parameters Database Completes both operations listed above Use the slewing keys to highlight your selection and press ENTER An X appears in the box Press OPTION to complete the MASTER RESET and proceed to the live screen You can adjust the EPOCH LT s screen for maximum viewing under the harshest and most extreme lighting conditions To adjust the screen follow these steps 1 Press 2nd F CAL CONTRAST 2 Use the slewing keys to position the highlight bar over the appropriate selection 3 Use the slewing keys to adjust the se
21. display to the split screen s 2 4 6 8 18 VEL 3127 m s FULLWAVE DATE 097 17 04 ZERO 6 688 us ENERGY LOW TIME 17 07 8 8 DAMP 5 DELAY 6 688 mm 8 68 mm PULSE ECHO START WIDTH LEVEL ALARM 11 300 186 741 37 2 216 73 7 817 OFF Figure8 Split Screen Display 2 Press ENTER several times to toggle through the instrument parameters 3 Use the 4 lt 4 and gt keys to change the setting from the current highlighted function 3 5 3 Display Flags and Markers To indicate when particular display functions are active a set of flags and markers appear on the right side of the waveform display Part 910 258 Indicates the 2nd F key has been pressed The unit is waiting for you to press one of the second function keys Press 2nd F again to cancel Indicates the EPOCH LT is in the Peak Depth mode thickness and 1 soundpath measurements are made to the peak of the highest amplitude AN signal within the flaw gate This symbol also appears when the amplitude display is active as all amplitude measurements are made to the peak of the signal Indicates the EPOCH LT is in the Edge Depth mode and all thickness within the flaw gate 1 and soundpath measurements are to the leading edge of the first signal 4 Indicates the EPOCH LT is in the optional Echo to Echo Peak peaks of the two selected signals A Measurement mode and the measurement is being made between the 31 EPOCH LT 32 ah
22. distance projection to the reflector j depth to the reflector NY MW VVE soundpath leg in which the particular reflector is located Ist 2nd 3rd 4th beyond 4th The selection of the Measurement modes Peak Depth or Edge Depth and the ability to toggle the soundpath reading are shown above See Making Thickness Readings on page 46 Any signal breaking the gate threshold generates the display of soundpath data To setup information in the first leg of the soundpath follow these steps 1 Enter a value of 0 for material thickness into the EPOCH LT when calibrating 2 Press 2nd F ANGLE THICKNESS 3 Press F1 or use y until the thickness value reads 0 00 With this set up all soundpath data is treated as if the information is in the first leg When working beyond the first leg it is imperative that you enter an exact thickness of the material into the EPOCH LT Press 2nd F ANGLE THICKNESS and use 4 v1 4 and gt to enter the proper thickness You can also use the function keys to quickly select preset values This value is then used to calculate the depth to a reflector that lies beyond the first leg 6 6 Measuring Signal Amplitude When estimating discontinuity size the instrument is adjusted so that a particular gain setting and screen height represent the echo amplitude produced by a known size reflector in a reference standard In general a signal with smaller amplitude may indicate a
23. how to adjust the preset values Once the scanning gain is setup press F4 to toggle the scanning gain On and Off as necessary When a discontinuity is located within the test piece the EPOCH LT provides a D value corresponding to the discontinuity However in order to display a D value the gated echo must peak at an amplitude less than 100 FSH Often you will have to press F4 to turn off scanning gain and bring the echo peak onto the screen In some cases further gain adjustments are necessary Using Software Options 9 9 4 Calculating A and C Values When a gated echo has a peak below 100 FSH the EPOCH LT automatically calculates the A and C values necessary to provide a D value In order to calculate the A value the EPOCH LT automatically calculates the required dB value to bring the gated echo to 80 FSH In order to calculate the C value the EPOCH LT uses the data in the soundpath calculator to generate an attenuation factor Note For this calculation to be accurate you must enter the correct thickness for the test piece The EPOCH LT displays the value for D in the upper right portion of the A Scan waveform display gt 4 GAIN 47 1dB RANGE 2 688in 0 990 REJECT 2 1 401 8 998 e in 0 2 6 i VEL 1298in fus FULLWAVE D f ZERO 12 87 us ENERGY HI ANGLE 45 0 DAMP 5 a DELAY 6 688 in THICK 6 666 in PULSE ECHO GATE START WIDTH LEVEL ALARM 1 8 922 8 881 2 9 139 EF B Figure 45
24. in welds This code uses the following formula to develop an indication rating for a reflector found during an inspection A B C D where A Discontinuity Indication Level dB B Reference Indication Level dB C Attenuation Factor 2 soundpath in inches 1 inch dB D Indication Rating dB An AWS D1 1 inspector must take the Indication Rating D that is calculated based on A B and C to an Ultrasonic Acceptance Rejection Criteria table produced by the AWS in order to classify the severity of the discontinuity that has been located When performing an inspection you are required to develop an AWS report that lists the values for all variables listed above as well as transducer information discontinuity length and location and your overall evaluation of the discontinuity 9 9 1 9 9 2 Part 910 258 Using Software Options For further details regarding the test equipment methods interpretation and classification requirements for these inspections refer to the AWS D1 1 Code Book AWS D1 1 and the EPOCH LT Panametrics NDT developed the AWS D1 1 software option for the EPOCH LT to simplify your tasks and lower overall inspection time This is accomplished by having the EPOCH LT perform some required calculations automatically and also by allowing you to document discontinuities in the EPOCH LT s datalogger for reporting purposes The EPOCH LT can also transfer inspection data to the G
25. is determined by the roof angle of the particular dual transducer We recommend that the distance calibration is carried out using a step block that covers the range of interest Be careful interpreting thickness readings made outside the calibrated range The EPOCH LT does not have V Path Correction therefore there may be some non linearity within the calibrated range depending on the minimum thickness used in the calibration process The zero offset value of dual element transducers can vary significantly at extreme temperatures If the temperature changes more than a few degrees from the temperature at which the zero offset value was established re check its value If thickness measurements are to be made over a wide temperature range we strongly recommend the use of Panametrics NDT dual transducers that are designed for high temperature applications These have built in delay lines with a stable sound velocity that does not change significantly with temperature Specific recommendations are Panametrics NDT D790 SM and D791 dual element transducers To calibrate using a Dual Element transducer follow these steps 1 Follow the initial set up procedure outlined in Section 7 1 Connect the transducer to an appropriate cable and then connect the cable to the transducer posts on the EPOCH LT Change the Test mode to Dual Also when using a dual element transducer the Gain setting is generally set very high so that the leading edge o
26. of adjusting the unit so that it measures accurately on a particular material using a particular transducer at a particular temperature You must adjust the Zero Offset and Velocity parameters of the EPOCH LT during calibration Zero Offset sometimes referred to as probe delay compensates for the time between initiating the Main Bang and the entry of the sound into the test piece The unit must be programmed with the correct Velocity setting so that it matches the material velocity of the test piece The EPOCH LT has an advanced Auto Calibration feature which provides for a fast and easy calibration process The following sections detail the procedure to calibrate the EPOCH LT when using the four basic transducer configurations straight beam delay line dual element and angle beam Note Do NOT use the Auto Calibration feature when the EPOCH LT is in the following modes Microsecond Time Of Flight DAC TVG Topics are as follows e Getting Started e Calibrating with a Straight Beam Transducer e Calibrating with a Delay Line Transducer e Calibrating with a Dual Element Transducer e Calibrating with an Angle Beam Transducer Getting Started Until you are completely comfortable operating the EPOCH LT we recommend that a basic review and set up procedure be used prior to starting the actual calibration The split screen feature of the EPOCH LT is useful for this as it lets you simultaneously view the waveform display and all i
27. 1 523 2 8 872 6 326 AdB Figure 30 Locating the Beam Index Point 4 Hold the probe stationary once you have peaked up the signal and mark the side of the transducer wedge directly over the 0 mark on the block This is the BIP the point at which the sound leaves the wedge and enters the material with maximum energy Verifying the Refracted Angle Beta The refracted angle of the probe should already have been previously entered into the EPOCH LT in the initial steps of the calibration procedure Although the wedge may be marked 45 for example the actual refracted angle may be slightly different due to the properties of the test material or the amount of wear on the wedge It is necessary to verify the actual angle This ensures the EPOCH LT s soundpath calculations are accurate To verify the refracted angle follow these steps 1 Position the probe over the appropriate angle mark on the block which is 45 for this example 7 5 3 Part 910 258 Calibrating the EPOCH LT 46 6 IW TYPE 1 REFERENCE fA Figure 31 Verifying the Refracted Angle 2 Move the probe backward and forward to peak up the echo coming from the large circular hold in the side of the block The circular hole may be filled with Plexiglas but the procedure is the same ip The Peak Memory feature on the EPOCH LT is an excellent tool to aid in Tip finding the peak of the signal Hold the probe stationa
28. 4 Expanded Memory The standard datalogger capacity in the EPOCH LT allows for a combination of 100 waveforms calibrations or 2 000 thickness readings The Expanded Memory option provides the EPOCH LT with a total capacity of 500 waveforms calibrations or 10 000 thickness readings If an EPOCH LT is purchased with the Expanded Memory option there is no further setup that is required by you The instrument s datalogger is simply able to store more information before reaching its capacity To confirm that the Expanded Memory option is active in a particular EPOCH LT press the OPTION key If the Expanded Mem selection has a filled in box next to it the option is active Note To determine the remaining capacity in the EPOCH LT datalogger press 2 F ID to enter the datalogger screen The remaining number of waveforms or thickness readings that can be saved is displayed in the center of the screen Echo to Echo Measurement Mode Using the Echo to Echo software option you can make measurements between successive echoes Measurements can be made between two consecutive backwall echoes or between an interface echo and any other selected signal This provides the capability to measure thickness through coatings or to do low speed immersion testing A second gate Gate 2 is used to capture data from the second backwall echo Echo to Echo readings are made by calculating the separation between the detected echoes in Gate 1 and Gate 2 E
29. 8 5 Saving Waveforms and Thickness Readings 000 eee eens 74 8 6 Incrementing ID Codes vis cide ea nae bebe ddaaw ceed aiohi bv ddaw anena 75 8 7 Recalling Transducer Calibrations and Waveforms 4 75 9 Using Software Options ssssesesesescecesecesescececeseseseeoeoeo 77 9 1 Defining Active Inactive Opuons 2000 2 8 ye tiee Gees ruen eee ek Sees 77 9 2 Distance Amplitude Correction DAC 0 0 0 0 eee eee eee 78 9 2 1 Drawing DAC Curves 5 a9 tsi0o 4 yale paw say oe Pea Ae ieee 78 9 2 2 Special Considerations for JIS Z3060 DAC Curves 80 9 2 3 Saving and Recalling DAC Curves 0 0 0 ee ee eee 80 9 2 4 Setting Alarms in DAC Mode 0 0 eee eee eee 80 92 5 Exiting DAC MOde 4 0 iss y caspase bu iGO NER Ge eA Ree 81 9 37 Time Varied Grain TVG r gt eed a es Bae abet eka gE Ree SRS 81 9 3 1 Activating and Calibrating TVG 0 00 eee 81 9 3 2 Saying and Recalling TVG Setups 4 44 04 sein scnyed bad ee aes betas 82 O23 Re TVG Mode 2S ia kt ore ote ind a de ot A Bs fe 83 9 4 Low Pulse Repetition Frequency PRF 0 0 00 eee 83 9 4 1 Activating Low PRF Mode 0 cee eee eee eee 83 942 Exiting Low PRF Mod 0 2 22 ccc nce taee sc brageenueriadwee es 83 9 5 Expanded Memory ovate yes pitch nie ad Sto a ne ere tea Gelade Gate ae fete 84 9 6 Echo to Echo Measurement Mode 0 0 0 0 cece eee ee eee
30. 9 2 Use the left and right arrows to move to the previous or next space Tip From the live A Scan screen use the function keys as shortcuts For example F1 Enter any number between 0 9 F2 Move to the previous space F3 Move to the next space F4 Delete an entry F5 Exit the screen Creating Files and ID Codes Thickness readings and waveforms are stored in the EPOCH LT datalogger in a file with an associated ID You can either manually enter file names and IDs using the EPOCH LT s keypad or create them in the GageView Interface Program and download them to the instrument Contact Panametrics NDT or your local representative for more information on the GageView Interface Program You can create file names in the EPOCH LT s Memory screen in preparation for saving thickness readings and waveforms On entering the memory screen a cursor appears at the first available empty file location If the cursor is flashing over an existing file use the down arrow key to move to the next available empty file location You can enter a filename date and time Wg oe EEN AE E seeessecek File Humber File Hame Date Time Hote Figure 39 Entering File Information The following rules and conditions apply e The file name is limited to eight characters with an extension of three characters If no file name is assigned the instrument automatically assigns a generic name FILENAME 001 FILENAME 002 and so forth e You can manually enter
31. ANTIES WHETHER STATUTORY EXPRESSED OR IMPLIED INCLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND WARRANTIES ARISING FROM THE COURSE OF DEALING OR USAGE OR TRADE EPOCH LT Table of Contents Table of Contents Warranty Table of Contents 1 Preface an oaee PCR 555K aR OER E Oe Nee AURORE OLE Ce RUE LL Product Deseripuon 2 sss hen oh oe ie Get Ee a ot Be ae doe anit he lcd ADOUE THIS Document i 423 ofitn a ee tis eee UR ails hike hg te 13 Auden e as ceils Gua esta EEE ces toner od A a eS oe aes rare wh Se ae LA SCOPE 2i8Guctesiee cegetaventphertsedaubed soe A EAE need tebe 1 5 Typographic Conventions 232 essences oer eee eee eos eww a ee ORS 1 6 Related Documentation 6 33 is basa dd Wag ees bee AAG wd Cae 1 7 If You have Documentation Comments 000 e eee eee ene Ie Techical Helpu ssia er a a tle oa eS Ot ok a ANE he ae ON 2 Operating the Power Supply cccccccccccccccccccscccccsceeces 2 1 Using AC Line PoWer i202 icceie nei cdo ckveutdewsubladaoheb aens 2 27 Using Battery POWeE sce se ics Ge he eee a Nee RO AS eR ee we 2 3 Operating Time for the Battery vo06 ecsiveee te coe ad ees ees ON a4 24 Replacing the Battery isene eiea a bead TEE TE d ae iw e he Ashes 2 5 Chareimg th Battery ahs tb teeta Let aN de Bg at bd Lahn le LO arab 3 Managing Basic Operations ccc ccc cece eee e cece cece eee ee eens 3 1 Powering up and Master Reset at Power Up
32. B DAC with respect to the selected curve If a different curve is selected the displayed amplitude changes accordingly Saving and Recalling DAC Curves DAC curves are saved and recalled in the same manner as any general waveform calibration With DAC mode active use the SAVE WAVE key to save the entire setup in the datalogger When a setup that was stored with a DAC curve is recalled the instrument automatically comes up in the DAC mode Setting Alarms in DAC Mode You can use the gates to set alarms while DAC is active When using the ASME or ASME 3 DAC modes all alarms are referenced to the primary curve When using the JIS DAC mode alarms are referenced to the highlighted alarm curve For example any DAC alarm can be set by using the positive threshold alarm on either Gate 1 or Gate 2 Any echo that falls within the gate and exceeds the DAC level triggers the alarm The alarm is triggered only if an echo exceeds the portion of the DAC curve immediately above the gate This same rule applies to the use of the minimum depth and negative threshold alarms while in DAC Note Alarms do not function in the area outside of the DAC curve 9 2 5 9 3 9 3 1 Part 910 258 Using Software Options Exiting DAC Mode To clear the DAC curve and return to the normal operation follow these steps 1 Press OPTION 2 Use the slewing keys to highlight the DAC selection and press ENTER to go into the DAC setup Use the slewi
33. CH LT for the appropriate transducer 2 Adjust the Gain so the peak of the highest amplitude echo to be used in the TVG setup is visible on the screen An echo cannot be used at a TVG point if its amplitude is greater than 100 screen height Press OPTION to display the Options menu 4 Use the slewing keys to position the highlight bar over the TVG selection and press ENTER to display the TVG setup choices 5 Use the slewing keys and the ENTER key to select On 81 EPOCH LT 9 3 2 82 6 Press OPTION to return to the A Scan display 7 Toseta TVG point position Gate 1 over the desired echo Adjust the gate level if necessary to make sure that the echo breaks the gate Press F1 Generally you should start with the highest amplitude calibration echo and work down to the smallest one You can go back to fine tune the gain level at any selected point by repositioning the gate on the appropriate echo and pressing F1 again If a point is outside the allowable time limits the unit beeps to indicate an error 8 Move Gate 1 to the appropriate position to capture the next point for the curve and press F1 again Repeat this step until all points for the curve are captured 9 Press F2 when all echoes have been set to lock the TVG setup The letters TVG will appear to the right of the screen to indicate that TVG is active A double thickness line appears at the top of the display to mark the area over which TVG
34. Echo to Echo Mode Use the minimum depth alarm when making Echo to Echo thickness readings In the Echo to Echo mode the minimum depth marker appears on Gate 2 To set the minimum depth alarm when in the Echo to Echo mode follow these steps 1 Position Gate 1 and Gate 2 over the desired areas See Using the Echo to Echo Software Option on page 47 Be sure the start position of Gate 2 is set to cover arange below the minimum depth value that will be used for the alarm Press 2nd F DEPTH AMP ECHO ECHO to activate the Echo to Echo Measurement mode Press 2nd F GATE 2 ALARM 2 to activate the alarm Press F3 to select the minimum depth alarm Use the 4 4 4 and gt keys to set the desired minimum value The range of minimum depth values is limited by the start and width settings of both gates Gate 1 must be positioned to detect the first back echo Also the minimum depth alarm value must be greater than the blank period between Gate 1 and Gate 2 and less than the Gate 2 width value Alarm Condition Storage When an alarm is active a capital letter A flashes to the right of the A Scan Alarm conditions can be saved in the EPOCH LT s datalogger All data with an alarm is flagged in memory by the character before the ID 53 EPOCH LT 54 7 1 Part 910 258 Calibrating the EPOCH LT Calibrating the EPOCH LT This chapter describes how to calibrate the EPOCH LT Calibration is the process
35. LT Spares can be purchased Part Description EPLT DAC DAC Distance Amplitude Correction EPLT TVG TVG Time Varied Gain EPLT DAC TVG DAC and TVG Combination EPLT MEM Expanded Memory EPLT LPRF Low PRF 30 Hz EPLT RANGE Extended Range 0 04 400 1 mm 10 000 mm EPLT ECHO Echo to Echo Measurement Software EPLT CSC Curved Surface Correction EPLT AWS American Welding Society Structural Welding Code Table 9 Instrument Software Options 105 EPOCH LT 106 Part Description EP4P IP KIT USB EPOCH 4PLUS Interface Program includes EP4P IP EP4P C USB 6 EP4P IP EPOCH 4PLUS Interface Program software CD ROM only EP4P C USB 6 EPOCH 4PLUS and LT USB Cable Table 10 PC Interface Program Part Description EPLT EW Extended Warranty One additional year 36DLP CC Plastic Transport Case EPLT EC External Stand Alone Charger base only PLUS RPC Rubber Protective Carrying Case includes EP4 CH EP4 CH Chest Harness for Rubber Protective Case EPLT DP Screen Protective Screen Cover Quantity 10 Table11 Optional Hardware Accessories Documentation Comments Panametrics NDT is always interested in improving its documentation Please complete this questionnaire and return your responses to Panametrics NDT Attention NDT Marketing Dept Technical Publications You can also email your comments to info panametrics ndt com Attention NDT Divis
36. a single test block of known thickness You can use multiple backwall echoes instead of coupling on both a thin step and a thick step You can leave the transducer coupled on the thin step and instead move the gate over to one of the multiple backwall echoes and enter the correct soundpath thickness 2 3 4 etc multiple of the first backwall echo during the velocity portion of the calibration Part 910 258 61 EPOCH LT 7 4 62 Calibrating with a Dual Element Transducer The sample delay line calibration described below is performed using Panametrics NDT transducer part number DHC711 RM with a frequency of 5 0 MHz and an element diameter of 0 25 6 mm The calibration requires a test block with two known thicknesses made from the material to be measured Ideally the two thicknesses should represent thicknesses that are both below and above the expected thickness of the material to be inspected For this example we are using a Panametrics NDT standard 5 step steel test block part number 2214E It has steps measuring 0 100 0 200 0 300 0 400 and 0 500 Note Note If the EPOCH LT is set to work in metric units the calibration process is exactly the same except that the entries below will be in millimeters rather than inches Due to acoustic characteristics of dual transducers a non linearity in the distance calibration occurs as the thickness of the material decreases The point of maximum sensitivity
37. acteristics of an ultrasonic test system indicating its ability to respond in a proportional manner to arange of echo signals produced by specified reflectors variable in time usually a series of multiple back reflections Longitudinal Wave Mode of wave propagation characterized by particle movement parallel to the direction of wave travel Term Appendix C Glossary Definition Main Bang Slang term used to describe the Initial Pulse Voltage Mode Conversion Changing a portion of a sound beam s energy into a wave of a different mode due to refraction at incident angles other than zero degrees In NDT this usually involves conversion of longitudinal waves into shear waves or surface waves Peaking Up Maximizing the height of any indication displayed on the CRT screen by positioning the main axis of the sound beam directly over the reflector Penetration The ability of the test system to overcome material loss attenuation that is the ability of the sound beam to by pass small reflectors such as grain boundaries and porosity in the specimen Piezoelectric Elements A family of elements such as lead metaniobate quartz lithium sulfate that possess the characteristic ability to produce a voltage differential across their faces when deformed by an externally applied mechanical force and b change in their own physical configuration dimensions when an external voltage is applied to them
38. ad Functions 22 Managing Basic Operations Pe English Int Color Function Blue Screen Freeze Holds displayed waveform until FREEZE is pressed a second time Purple Save Thickness Reading Saves displayed thickness reading in current file If the EPOCH LT is in Time of Flight mode the value will be in microseconds Purple Save Waveform Saves the current waveform and instrument setup parameters in current file Purple Enter Press this key multiple times to ENTER toggle through the setup parameters ALARM 1 1 Red Gate 1 Controls the positioning of GATE 1 Gate 1 on the display Press this key multiple times or use the function keys to access Gate 1 Start Gate 1 Width and Gate 1 Level White Gate 1 Alarm Activates the alarm mode for Gate 1 Use the function keys to access the Threshold or Minimum ALARM 1 Kl Depth Alarm pla Re ALARM 2 H 2 Red Gate 2 Controls the positioning of Gate 2 on the display Press this key 2 multiple times or use the function keys to access Gate 2 Start Gate 2 Width and Gate 2 Level White Gate 2 Alarm Activates the alarm mode for Gate 2 Use the function keys to select the Threshold or Minimum ALARM 2 H 2 Depth Alarm Red Table 3 Keypad Functions Continued 23 EPOCH LT 24
39. add Reject while in the unrectified RF display To access the Reject function follow these steps 1 Press 2ndF VEL REJECT 2 Use the function keys to select preset values or use the 4 y 4 and gt keys to adjust the reject level upward or downward Any signal whose amplitude is less than or equal to the specified reject level is eliminated from the display Peak Memory The Peak Memory function enables the display to capture and store on the screen the amplitude of each display point The display updates each pixel if a signal of greater amplitude is acquired When a transducer is scanned over a reflector the signal envelope or echo dynamic as a function of transducer position is held on the screen In addition the current live waveform is displayed at the appropriate place within the echo envelope This function is useful when it is necessary to peak up an indication during an angle beam calibration Note The Peak Memory function cannot be activated in the unrectified RF display mode To activate Peak Memory follow these steps 43 EPOCH LT 5 3 44 1 Press PEAK MEM A P appears at the right side of the display to indicate the function is active 2 Scan over the reflector to acquire the echo envelope Continue to scan slowly until the live waveform peak matches the peak amplitude of the echo envelope When these two points match the signal will be peaked up 3 Press PEAK MEM a
40. age View Interface Program to aid in report generation This program allows you to view the instrument setup parameters the waveform generated by a discontinuity the discontinuity s soundpath and location information and all values for the AWS D1 1 formula variables Operating the AWS D1 1 Software The first step in operating the EPOCH LT for AWS D1 1 inspections is to calibrate the instrument for the transducer and test conditions Leia Se ECHO ECHO EXT RANGE EXPANDED MEM LOFTLON LiL PUL LWAWE DATE 11 18 04 j i REY HI TIME 13 32 ANG LE 45 o P 56 o DELAY 0 800 in THICK 8 808 im SE ECHO BATE STARI H LEVEL ALARM 1 1 23 OFF OFF OFF Pp Figure 43 AWS D1 1 Software Option Activated in the Options Menu When AWS D1 1 is activated the EPOCH LT function keys provide the following options F1 REF B store the dB value from a reference reflector F2 No Function F3 No Function F4 SCAN DB toggle the scanning gain between a selected value and zero dB F5 AUTO 80 adjust a gated signal to 80 FSH 87 EPOCH LT 9 9 3 88 After the AWS option is activated from the Options menu you must set a REF B value in order to begin an inspection This number represents the gain level necessary to bring the echo from a reference reflector to 80 Full Screen Height FSH The reference reflector is often a side drilled hole in the calibration block used for the angle beam calibration Other reference re
41. ally change a When an ID is listed that has a corresponding waveform and setup parameters saved with it a Recall selection is available by pressing F2 b The Recall selection disappears when an ID is listed that contains a measurement value only depth amplitude or TOF Press F2 for Recall when the appropriate ID is listed at the top of the screen The calibration is recalled and the EPOCH LT is in the Freeze mode You cannot change any parameters while in Freeze mode Press FREEZE to go to the live screen The EPOCH LT is ready for use with the same parameter settings used when this calibration was initially saved Using Software Options 9 Using Software Options This chapter describes the different software options available for the EPOCH LT The EPOCH LT is intended to be a highly versatile instrument It is capable of being configured to perform specialized functions related to certain applications or code requirements Because some inspectors may not make use of these functions these functions are offered as software options Contract Panametrics NDT or your local representative for information on ordering these options Topics are as follows e Defining Active Inactive Options e Distance Aplitude Correction DAC e Time Varied Gain TVG e Low Pulse Repetition Frequency PRF e Expanded Memory e Echo to Echo Measurement Mode e Extended Range e Curved Surface Correction CSC e AWSD1 1 D1 5 9 1 Definin
42. alogger and Data Communication Features Incrementing ID Codes This feature automatically increments the EPOCH LT s ID code every time you press the SAVE THICK or SAVE WAVE key You do not have to enter a new ID every time a reading is saved For example a user wants to save several readings when inspecting an aircraft wing Begin by entering an initial ID of 01 Press SAVE THICK or SAVE WAVE to save desired thickness readings and waveforms Every time you press one of these keys the ID code listed at the top of the screen increments by one character value In this example the first thickness reading waveform is saved with an ID code of 01 the second one with an ID code of 02 and so on Some guidelines for the auto ID incrementing features are e Only the portion of the ID consisting of digits and letters no punctuation marks beginning with the rightmost letter and extending leftward to the first punctuation mark or leftmost character whichever comes first is incremented e To have the EPOCH LT properly increment first create and hold using zeros the maximum number of needed digit positions To save 999 readings enter 001 as the first ID code If an initial ID code of 1 is entered the EPOCH LT only increments up to 9 and beeps The message error Id Cannot Increment appears Press F1 to exit and enter a new ID code to continue saving readings e After saving several readings t
43. ansducer being used it may be impossible to obtain a proper reading on a very thin material 4 Position Gate 1 so that the first backwall echo from the known thickness step exceeds the gate threshold Adjust the gain setting so that the echo amplitude is approximately 80 Calibrating the EPOCH LT eae AE ee A GAIN 43 8dB RANGE 999in 0 25 REJECT 0 2 MIN DEPTH 250 Pe rca Meee e Ae VEL 2383in us FULLWAYE DATE 09 18 04 ZERO 0 000 us ENERGY LOW TIME 08 58 ANGLE 4 DAMP 58 DELAY 8 688 in THICK 6 668 in PULSE ECHO CAL GATE _ START WIDTH LEVEL ALARM 1 8 484 43 2 OFF 2 15 962 6 576 OFF OFF 1 START 1 WIDTH 1 LEVEL AUTO 88 Figure 17 Calibrating for a Thin Block Using a Straight Beam Transducer 5 A thickness reading appears in large text above the A Scan Once a steady reading is achieved press ZERO OFFSET The screen freezes and a pop up box appears on the screen Use the 4 and slewing keys to enter the exact known thickness of the test sample ENTER VALUE FOR THIN STANDARD 000 20 Figure 18 Entering a Thin Standard Value 6 Press CAL The display returns to the live A Scan Couple the transducer to the THICK calibration block step For this example the transducer is coupled to the 0 500 step 7 Position Gate 1 so that the first backwall echo from the known thickness step is exceeding the gate threshold Adjust the gain setting so that the echo amplitude is approxima
44. as inter granular stress corrosion cracking IGSCC The inspector s job can be complicated by the geometry of the test specimen and also by the specific characteristics of the defect itself In instances where the pipe counterbore is close to the weld root itis possible to have three signals that all appear quite close to each other from the weld root the counterbore and the crack itself Use the Zoom function to improve the 6 9 1 Part 910 258 Using the Gates visual resolution of the EPOCH LT display so that each individual signal can be more easily identified When evaluating a crack signal the inspector s attention is usually focused on the leading edge of an indication By observing the number and location of small peaks along the leading edge of the signal itis possible to make some assumptions regarding the presence and location of different facets of the crack Use the Zoom function to get a much more detailed view of an indication and thus make better judgements regarding flaw location and depth Zoom is useful when inspecting particularly large or thick components when detail is lost due to using long screen ranges Use the Zoom function to look at small sections of the test piece without disturbing the instrument s original calibration Activating Gate Alarms The EPOCH LT features a variety of alarm configurations that can be used in either the Single or Dual Gate modes An alarm on Gate 2 can only be set if Gate 2
45. bration mode To exit Auto Calibration mode at any point press ENTER 67 EPOCH LT 68 Position Gate 1 so that the echo reflection from the 4 arc is exceeding the gate threshold This should be the first large echo after the Main Bang Adjust the gain setting so that the echo amplitude is approximately 80 A thickness reading appears in large text above the A Scan ri 2 4 6 8 168 VEL 8 128B8in us FULLWAVE DATE 89 18 84 ZERO 3 437 us ENERGY MED TIME 09 35 ANGLE 4 8 DAMP 5 DELAY 8 000 in THICK 6 666 in PULSE ECHO CAL GATE START WIDTH LEVEL ALARM 1 3 628 1 523 342 2 8 872 8 370 OFF 18 AdB Figure 32 Calibrating for Distance 5 Press ZERO OFFSET once the reading is steady The screen freezes and a pop up box appears on the screen Use the 4 and slewing keys to enter the exact known thickness of the test sample ENTER VALUE FOR THIN STANDARD 004 00 Figure 33 Entering a Thin Standard Value 6 Press CAL The display returns to the live A Scan Position Gate 1 so that the echo from the 1 crescent is exceeding the gate threshold This echo is generally located at approximately the ninth or tenth screen division and usually the 3rd echo after the Main Bang Adjust the Gain setting so that this echo amplitude is approximately 40 A thickness reading appears in large text above the A Scan Note Another echo may be present on the screen at approximately the eighth or ninth screen di
46. cho to Echo thickness readings cannot be made in the unrectified RF display mode Calibrate the EPOCH LT and follow these steps to make Echo to Echo thickness readings See Calibrating the EPOCH LT on page 55 for more detail about calibration 1 Position Gate 1 over the region where the first backwall echo is expected to appear 2 Press 2nd F DEPTH AMP ECHO ECHO to activate the optional Echo to Echo measurement mode The following will appear in the function boxes at the bottom of the display F1 EDGE F2 PEAK ll 3 Select either edge to edge or peak to peak The icon MA appears for peak to peak or AA appears for edge to edge to the right of the display to indicate Echo to Echo measurements are being used If Gate 2 is off and the optional Echo to Echo mode is turned on then Gate 2 is automatically turned on 4 Define the Blanking Period to avoid possible false readings that could occur due to transducer ringing or material noise A dead zone or blanking period is necessary after 9 7 9 8 Part 910 258 Using Software Options the detection of the first echo This period is defined during set up as the separation between the start of Gate and the start of Gate 2 When an echo is detected in Gate 1 Gate 2 start automatically adjusts to trail the detected echo by the blank period For example if Gate 1 Start is set to 0 25 6 35 mm and Gate 2 Start is set to 0 40 10 mm then the blank period is 0 15
47. city 95 EPOCH LT 96 Steel low alloy 0 2259 5734 2 Stainless Steel 347 0 2278 5790 1 Titanium 0 237 5990 3 Tungsten drawn 0 2129 5410 1 Uranium 0 133 3370 3 Water 0 0590 1498 5 Zinc rolled 0 1657 4210 1 Zinc extruded 0 1756 4460 2 Table 6 References 1 Development Laboratory Panama City Florida 1971 Sound Velocities of Various Materials Longitudinal Wave Velocity Folds D L Experimental Determination of Ultrasonic Wave Velocities in Plastics Elastomers and Syntactic Foam as a Function of Temperature Naval Research and Fredericks J R Ultrasonic Engineering New York John Wiley amp Sons Inc 1965 Handbook of Chemistry and Physics Cleveland Ohio Chemical Rubber Co 1963 Mason W P Physical Acoustics and the Properties of Solids New York D Van Nostrand Co 1958 Papadakis E P Panametrics unpublished notes 1972 Appendix C Glossary Part 910 258 Term Appendix C Glossary Definition Acoustic Impedance A material property defined as the product of sound velocity C and the material s density d Acoustic Interface The boundary between two media of different acoustic impedance Acoustic Zero The point on the CRT display that represents the entry surface of the specimen Amplifier An electronic device that increases the strength of a signal fed into it by obtaining power from a s
48. de Range setting and currently selected parameter are constantly displayed e A numeric display shows thickness soundpath amplitude or time of flight data pertaining to a gated signal Use DEPTH AMPL to select which information to show Middle of the screen e Displays the waveform e Inthe background a numbered graticule shows signal amplitude on the vertical axis and screen division number or the function presets on the horizontal axis To view the screen divisions instead of the function presets press 2nd F then ZERO OFFSET DIV e On the right side of the waveform display a set of display flags and markers appear when certain functions are active See Display Flags and Markers on page 31 Bottom of the screen e Displays the preset values for many of the parameters These are accessed via the function keys e The battery level icon is constantly displayed in the bottom right corner Split Screen Display The split screen display presents a condensed waveform and a status display that shows all instrument set up data This screen is useful when establishing the initial instrument settings as it enables you to quickly check all set up information and make adjustments while viewing the waveform display Even in the split screen mode the A scan still has enough resolution to produce accurate waveforms To display a split screen follow these steps 1 Managing Basic Operations Press DISPLAY to toggle the
49. displayed at the bottom of the screen Each preset value has a corresponding function key For example press RANGE to view various preset range values at the Part 910 258 Managing Basic Operations bottom of the display Press any one of the function keys to set the EPOCH LT s range to that displayed value The main keypad is laid out with functional grouping of keys for easy identification The main keypad contains the primary operating keys of the EPOCH LT Most parameters on the EPOCH LT can be directly accessed by pressing the appropriately labelled key Some parameters are second functions These can be accessed by first pressing 2nd F and then the desired function The second function is written directly above the key For example to access ZOOM press 2nd F and then RANGE Once you access a parameter change it through one of two methods Use the function keys to directly access preset values Alternately use the green slewing keys 4 v1 4 and gt to change the parameter in smaller increments ECT res a D Figurel English Keypad 21 EPOCH LT Figure 2 International Keypad Main keypad functions include English Int Color Function DER Blue Sensitivity Adjusts system sensitivity White Reference Level Sets a gain reference level and allows addition of scanning gain in 6 dB or 0 1dB increments REF ABEXX Blue Table 3 Keyp
50. e contents e Ability to transfer data between the unit and a PC Topics are as follows e Defining the Datalogger Storage Capacity e Using the Memory Screen e Entering Numeric File Names and ID Codes e Creating New Files and ID Codes e Saving Waveforms and Thickness Readings e Incrementing ID Codes e Recalling Transducer Calibrations and Waveforms Defining the Datalogger Storage Capacity The EPOCH LT datalogger stores the following data e Thickness Reading Identifier ID code Alarm conditions Peak Edge Depth Mode Indicator Soundpath leg of measurement Thickness Soundpath values Edge or Peak Depth mode Current and Maximum Amplitude data Amplitude mode or Time of Flight data Microsecond mode e Complete Waveform Parameter Setup All data listed in the Thickness Reading section Waveform screen Peak Memory echo envelope Complete setup parameters 71 EPOCH LT 8 2 72 Flag status Freeze Zoom Peak Memory etc The EPOCH LT datalogger can store a maximum combination of 2 000 thickness readings or 100 waveforms Note A software option is available to increase the storage capacity to 10 000 thickness readings or 500 waveforms See Expanded Memory on page 84 The EPOCH LT can save information in 500 separate files Files 1 9 are fixed files meaning that each file can only store one complete waveform parameter setup with an associated identifier ID code This structure allows yo
51. e instrument sensitivity follow these steps 1 Press GAIN 2 Use the function keys to select preset values for course adjustment 3 Move the gain upward or downward with the 4 and keys for fine adjustments The current system sensitivity is displayed and highlighted in the upper left corner 4 Adjust gain in 0 1dB increments by pressing the 4 or y key once Hold the 4 or key to gradually increasing slewing rate Total system sensitivity is 100 0 dB Using AUTO 80 AUTO 80 is an excellent tool to quickly adjust the gain dB setting bringing the peak of a reference echo to 80 full screen height AUTO 80 is especially useful in combination with welding applications and codes that require quick gain adjustments to bring an echo to 80 screen height You can use AUTO 80 to bring an echo to 80 full screen height in either Gate 1 or Gate 2 To use Auto 80 with Gate 1 follow these steps 1 Press GATE 1 2 Use the green slewing keys to position the gate over the desired echo Be sure the echo breaks the gate threshold 3 Press F5 The peak of the highest amplitude echo breaking the Gate 1 threshold is brought to 80 screen height 37 EPOCH LT 38 1 070 53 HIN DEPTH 1 069 d in 1 START 1 WIDIH 1 LEVEL AUTO o0 Figure10 Before Activating AUTO 80 To use Auto 80 with Gate 2 follow these steps 1 2 3 Press GATE 2 Press F4 to turn on the gate
52. e the slewing keys to highlight Off and press ENTER 4 Press OPTION to return to the A Scan display Low Pulse Repetition Frequency PRF Pulse Repetition Frequency PRF is a measure of how often the transducer is being pulsed by the electronic circuitry in the EPOCH LT The standard PRF setting of the EPOCH LT is Auto where the PRF changes automatically from 60 Hz to 180 Hz depending on the range setting For some applications it may be necessary to lower the PRF rate below 60 Hz to avoid a phenomenon known as wrap around noise This can sometimes occur when testing long soundpaths and can result in random noise and echoes on the A Scan display When the Low PRF option is activated the EPOCH LT maintains a fixed PRF of 30 Hz Activating Low PRF Mode To activate the Low PRF mode follow these steps Press OPTION Use the slewing keys to highlight the PRF selection and press ENTER Use the slewing keys to highlight LOW and press ENTER Press OPTION to return to the A Scan display A PRF symbol displays on the right side of the screen to indicate that the Low PRF mode is enabled Bey coe Soe te Exiting Low PRF Mode To exit the Low PRF mode follow these steps Press OPTION Use the slewing keys to highlight the PRF selection and press ENTER Use the slewing keys to highlight Off and press ENTER Press OPTION to return to the A Scan display Be E T 83 EPOCH LT 9 5 9 6 8
53. edge mode is selected 4 Press F4 multiple times to allow you to select which of the soundpath readings depth surface distance or total soundpath is displayed in large bold text 5 Select F1 or F2 to put the EPOCH LT in the corresponding Depth Measurement mode 6 Select F3 to put the EPOCH LT into the Amplitude Measurement mode One of the following icons appears next to the upper right corner of the A Scan 4 Edge Depth ae Peak Depth While in Edge Depth mode thickness readings are made to the leading edge of the first signal to exceed the flaw gate level In Peak Depth mode thickness readings are made to the peak of the highest amplitude signal that falls within the gate 6 4 6 5 Part 910 258 Using the Gates If no refracted angle is entered a Minimum Depth value appears above the display This value refers to the minimum detected thickness value and is only updated if a lower value is measured To reset the minimum depth value press either GATE 1 or GATE 2 Note To obtain the most accurate and consistent thickness or soundpath readings select the Peak Depth mode The apparent arrival time of the leading edge of a signal varies with the signal amplitude As a result the instrument gain setting coupling conditions and any other factor affecting signal amplitude has an impact on the accuracy of a reading made in the Edge Depth mode The effects of these factors are no
54. el With the use of the DAC curve option the EPOCH LT is capable of drawing user defined DAC curves It is possible to select formats that are consistent with either ASME ASME 3 or JIS Z3060 code requirements When the ASME format is selected a single curve is drawn The ASME 3 format lets you draw three curves simultaneously at 0 dB 6 dB and 12 dB When the JIS format is selected up to eight segmented curves are drawn In all formats the signal amplitude as a percentage of the primary curve level is displayed on the screen Users can select to view this value in terms of a or dB In addition DAC alarms can be set to activate whenever an echo exceeds the primary curve level DAC curves can be saved in the EPOCH LT datalogger and recalled when needed Drawing DAC Curves To draw a DAC curve follow these steps 1 Calibrate the EPOCH LT for the appropriate transducer Adjust the Gain so the peak of the highest amplitude echo that is to be used in the DAC curve is visible on the screen An echo cannot be used in the curve if its amplitude is greater than 100 screen height 2 Press OPTION 3 Use the slewing keys to position the highlight bar over the DAC selection and press ENTER to display the DAC setup choices 4 Use the slewing keys and the ENTER key to select the DAC standard ASME ASME 3 or JIS and the signal amplitude units DAC or dB DAC 5 Press OPTION to return to the A SCAN display
55. em and the material being tested 97 EPOCH LT Term Definition Beam Index Point The point on the base of an angle beam probe s wedge from which the sound leaves the wedge and enters the specimen B Scan A sectional representation side view of a test specimen often performed in an immersion system This can be in the form of a photograph or recorder display Cal Block Velocity Calibration block velocity Couplant A material usually a liquid or gel used between the transducer and the test specimen to eliminate air from this space and thus facilitate the passage of sound waves into and out of the specimen Critical Defect Either the largest tolerable defect or the smallest intolerable defect The critical defect size is usually given by a specification or code Cross Talk An unwanted condition affecting dual element transducers in which acoustic energy travels from the transmitting crystal to the receiving crystal by routes other than the intended path through the material Damping Control A variable resistance across the pulser circuit output which shapes the excitation pulse Typically it is used to change pulse characteristics to optimize either penetration low damping or near surface resolution high damping Damping Material Any gel rubber like substance or other material which when used in the transducer results in a shorter ringing time of the piezoelec
56. ency Range Thickness Velocity Note Parameters that contain text such as Rectification cannot be adjusted Also parameters that are limited by hardware and or software constraints such as Damping cannot be adjusted To activate the Editable Parameters menu follow these steps 1 Press the OPTION key 2 Use the slewing keys to select the Editable Parameters option AWS D1 1 ECHO ECHO EXT RANGE Sra eee ee ee Oe EXPANDED MEM MP 8 16 DATE 12 17 64 OPTION EXIT NERGY LOW TIME 16 34 nJ A7 h H H DAMP DELAY 8 888 mm THICK 8 88 mm PULSE ECHO GATE START WIDTH LEVEL ALARM 1 71 863 72 198 37 2 OFF 2 216 73 7 817 OFF OFF Figure3 Selecting the Editable Parameters Option 3 Press ENTER The Editable Parameters screen opens Part 910 258 27 EPOCH LT EDITABLE PARAMETERS F2 F1 GAIN dB REJECT 2 a 48 808 4 8 1 88 8 588 1 10 000 25 008 10 000 28 008 8 666 4 188 2 98 5 88 0 2320 8 12868 5900 3248 6328 Figure4 Viewing the Editable Parameters Screen 4 Press the ENTER key to move downward to different Parameters 5 Use the left and right slewing keys to select which F1 F5 parameter to edit Edit each parameter using the up and down slewing keys EDITABLE PARAMETERS F1 F2 MORER 15 0 2 a 0A AAA 4 8 1 68 4 588 10 00A 10 00A 4 0AA 2 58 8 2326 5900 COLUMN T t CHANGE VALUE F DONE Figure5 Editing the Gain Parameter 6 Press the
57. ep Table 2 Typographic Conventions 12 1 6 1 7 1 8 Part 910 258 Preface Related Documentation The EPOCH LT works with the Gage View Interface Program For more information about this software program refer to the following instruction manual e GageView Interface Program Part Number 910 259 If You Have Documentation Comments Panametrics NDT is always interested in improving its documentation We value your comments about this manual and other Panametrics NDT documentation Complete the survey at the back of this manual and send your documentation comments to Panametrics NDT by using one of the following methods e Send comments to Panametrics NDT Attention Technical Publications e Email us at info panametrics ndt com In all your correspondence please include the title of the document its part number release date and the specific section on which you are commenting Technical Help Call Panametrics NDT and ask for a sales engineer to assist you EPOCH LT 14 2 1 2 2 2 3 Part 910 258 Operating the Power Supply Operating the Power Supply This chapter describes operation of the EPOCH LT using different power supply options Topics are as follows e Using AC Line Power e Using Battery Power e Operating Time for the Battery e Replacing the Battery e Charging the Battery Using AC Line Power AC line power is supplied via a charger adapter which includes a unive
58. er These IDs can be recalled to the live screen to restore the instrument s settings to what they were when the calibration waveform was initially saved The EPOCH LT can save a total of 100 500 with the Expanded Memory option complete waveform parameters setups Data is saved in the EPOCH LT datalogger in the currently displayed file and tagged with the ID code displayed on the screen The ID code automatically increments to the next ID in preparation for saving additional data See Incrementing ID Codes on page 75 To save thickness readings and waveforms to a different file already created in the EPOCH LT or a completely new file return to the Memory screen and position the highlight bar over the desired filename or on a newly created filename When you return to the live screen the EPOCH LT saves data at whichever file was highlighted when the Memory screen was exited The file name is also displayed on the top left of the live screen Note Every time the EPOCH LT is initially turned on the next available blank file is displayed The top left portion of the screen displays a blank line indicating that no file has been selected If you enter an ID and then attempt to start saving data the EPOCH LT automatically creates a new file name where the data is stored The file is named FILENAME XXX where the extension incrementally increases depending on the number of untitled files created 8 6 8 7 Part 910 258 Managing the Dat
59. er describes how to use the EPOCH LT gates Topics are as follows e Positioning Gate 1 e Positioning Gate 2 e Making Thickness Readings e Using the Echo to Echo Software Option e Locating Flaws with an Angle Beam Transducer e Measuring Signal Amplitude e Operating Time of Flight Mode e Using the Zoom Feature e Activating Gate Alarms Positioning Gate 1 Gate 1 is the primary flaw gate It provides thickness readings in both the A Scan and unrectified RF displays soundpath data when using an angle beam transducer signal amplitude time of flight data or minimum depth or threshold alarm triggers Movement of Gate 1 is controlled via the red GATE 1 key To access the starting position width or level of Gate 1 follow these steps 1 Press GATE 1 2 Press the appropriate function key Tip You can also access the start width and level by pressing GATE 1 multiple times Use the 4 lt and gt keys to position the gate Positioning Gate 2 Gate 2 is a secondary gate used when making echo to echo thickness readings or when multiple alarm gates are required To access Gate 2 follow these steps Press GATE 2 to view Gate 2 controls Press F4 for ON The movement of Gate 2 is done in the same manner as Gate 1 Press GATE 1 to switch back to control Gate 1 To turn Gate 2 off press GATE 2 followed by F4 oe by 45 EPOCH LT 6 3 46 Making Thickness Readings The EPOCH LT
60. ery not included Optional second year warranty available 93 EPOCH LT 94 Appendix B Sound Velocities Part 910 258 Appendix B Sound Velocities The following table lists the ultrasonic velocity in a variety of common materials This is only a guide The actual velocity in these materials may vary significantly due to a variety of causes such as composition preferred crystallographic orientation porosity and temperature For maximum accuracy establish the sound velocity in a given material by first testing a sample of the material Material V in usec V M S REF Alumina Al 03 99 5 0 4013 10190 2 Aluminum rolled 0 253 6420 1 Aluminum 6061T6 0 251 6383 2 Beryllium 0 5073 12890 1 Brass yellow 70 Cu 30 Zn 0 1850 4700 1 Brass yellow 70 Cu 30 Zn 0 1726 4385 2 Copper rolled 0 1972 5010 1 Duraluminum 17S 0 2487 6320 1 Fused Silica 0 2349 5968 1 Fused Silica 0 2335 5932 2 Glass crown 0 2008 5100 5 Glass flint 0 1567 3980 5 Glass pyrex 0 2220 5640 1 Iron Armco 0 2345 5960 1 Lead rolled 0 0771 1960 1 Lucite 0 1055 2680 1 Magnesium drawn annealed 0 2270 5770 1 Molybdenum 0 247 6250 3 Monel 0 2105 5350 1 Nickel 0 2377 6040 1 Nylon 0 1031 2735 2 Polyethylene 0 0705 1950 1 Polystyrene 0 0925 2350 1 Silicone Rubber RTV 0 0373 0948 4 Table 6 Sound Velocities of Various Materials Longitudinal Wave Velo
61. et values or adjust in 0 1 adjustments using the 4 and y keys Calibrating with a Straight Beam Transducer Use Panametrics NDT transducer part number A109S RM with a frequency of 5 0 MHz and an element diameter of 0 50 13 mm to perform the sample Straight Beam calibration The calibration requires a test block with two known thicknesses made from the material to be measured Ideally the two thicknesses should represent thicknesses that are both below and above the expected thickness of the material being inspected For this example we are using Panametrics NDT standard 5 step steel test block part number 2214E The steps measure 0 100 0 200 0 300 0 400 and 0 500 Note If the EPOCH LT is set to metric units the calibration process is exactly the same except that the entries below will be in millimeters rather than inches To calibrate using a Straight Beam transducer follow these steps 1 Follow the initial set up procedure outlined above Connect the transducer to an appropriate cable and then connect the cable to either of the transducer posts on the EPOCH LT 2 Press CAL A Cal symbol appears to the right of the A Scan signifying the EPOCH LT is in the Auto Calibration mode To exit the Auto Calibration mode at any point press ENTER 3 Couple the transducer to the THIN calibration block step For this example the transducer is coupled to the 0 200 step Depending on the frequency of the contact tr
62. f the backwall echoes appears as near vertical lines on the screen The leading edge is then used when making thickness measurements For this reason the EPOCH LT should be set to Edge Detection mode 2 Press CAL A Cal symbol appears to the right of the A Scan signifying the EPOCH LT is in the Auto Calibration mode To exit the Auto Calibration mode at any point press ENTER Part 910 258 Calibrating the EPOCH LT 3 Couple the transducer to the THIN calibration block step For this example the transducer will be coupled to the 0 100 step As noted above a higher Gain setting is required to produce a clean leading edge of the signal Do not be concerned with the jagged peaks of the echo Concentrate on the leading edge only Position Gate 1 so that the leading edge of the backwall echo from the known thickness step is exceeding the gate threshold A thickness reading appears in large text above the A Scan a z 4 6 8 18 VEL 2328in us FULLWAVE DATE 09 18 04 ZERO 3 437 us ENERGY MED TIME 09 15 ANGLE 4 DAMP 5 DELAY 4 888 in THICK 6 686 in DUAL CAL GATE START WIDTH LEVEL ALARM 1 0 071 0 786 43 2 OFF 2 16 081 6 588 OFF OFF 1 2H HdB 36 6dB 46 88 Figure 25 Calibrating for a Thin Block Using a Dual Element Transducer 5 Press ZERO OFFSET once the reading is steady The screen freezes and a pop up box appears on the screen Use the 4 and slewing keys to enter the exact known thickness of the test
63. flectors may be used provided that they meet AWS requirements for these inspections In order to store a REF B value you must gate the echo from the reference reflector and bring the echo to 80 FSH You can achieve this by pressing the GAIN key and adjusting the gain with the Up and Down arrow keys or by pressing F5 to automatically adjust the gain to bring the echo to 80 FSH Once the echo has the appropriate amplitude press F1 and the following screen will appear gt 4 GAIN 47 1dB RANGE 2 868B8in 0 460 REJECT 0 2 w 6 651 6 466 bd in 166 4 SAVE REF B VALUE REF B 47 1 dB 738 DAMP 5 DELAY 6 888 in 0 00 in PULSE ECHO START WIDTH LEVEL ALARM 0 396 6 881 29 2 OFF 9 139 0 325 OFF OFF i ee Figure 44 Pressing F1 to Store the REF B Value Adding Scanning Gain AWS codes require that an operator enter a certain amount of scanning gain to the REF B dB value allowing the operator to locate flaws that may be smaller or deeper into the test piece than the reference flaw By pressing F4 you can enter the amount of scanning gain necessary to perform the inspection as outlined by AWS code The EPOCH LT allows scanning gain to be entered in increments of 0 1 dB and 6 0 dB by default However you can customize these settings by using the Editable Parameters feature that is included with all EPOCH LT instruments This feature is located in the Options menu and there are on screen prompts explaining
64. from 0 to 80 full scale in 1 increments English metric or microseconds 0 025 to 0 6000 in usec 635 to 15240 m s Switchable between two stored velocity settings 0 to 350 usec 0 160 200 4 5 000 mm standard range at the velocity of longitudinal waves in steel Optional 0 04 400 1 10 000 mm Provides single echo or optional Echo to Echo thickness readings in large numerals or soundpath surface and depth display for angle beam testing Measures to either peak or leading edge of gated signal In addition selectable microsecond readout for time of flight measurements Fixed settings of 0 30 45 60 70 or variable from 10 to 85 in 0 1 resolution Variable over entire displayed range Variable from Gate Start position to the maximum displayed range Off or On with level adjustable from 2 to 95 of full screen in 1 increments for both Rectified and RF display modes 91 EPOCH LT 92 ZOOM PEAK MEMORY SCREEN FREEZE PULSER TYPE PULSE ENERGY DAMPING RECTIFICATION ANALOG BANDWIDTH TEST MODES ALARMS MEMORY IDENTIFIERS OPERATING TEMPERATURE STORAGE TEMPERATURE POWER REQUIREMENTS BATTERY BATTERY OPERATING TIME BATTERY RECHARGE TIME BATTERY STATUS TRANSDUCER CABLE CONNECTORS KEYPAD LANGUAGES USB COMMUNICATIONS Expands gated portion of display to full screen width Simultaneous display of live A Scan and peak envelope of A Scan disp
65. g Active Inactive Options Software options are accessed using the OPTION key The menu displays a list of available options each with a triangle or box preceding it The following table describes each symbol Symbol Description Unfilled triangle gt or box O The option is not activated Filled triangle P The option is active To activate an option move the highlight bar over a desired selection using the slewing keys and press ENTER Filled box W The option is active and no further adjustment is necessary Table 5 Active Inactive Software Options Part 910 258 77 EPOCH LT 9 2 9 2 1 78 Distance Amplitude Correction DAC A Distance Amplitude Correction DAC curve is used to plot amplitude variations of signals from reflectors of the same size but at different distances from the transducer Normally these reflectors produce echoes of varying amplitude due to material attenuation and spreading of the sound beam The purpose of a DAC curve is to graphically compensate for material attenuation nearfield effects beam spread and surface roughness After plotting a DAC curve reflectors that are the same size as those used for creation of the curve produce echoes that peak along the curve despite different locations in the test piece Similarly reflectors that are smaller than those used to create the curve fall below the level while larger reflectors exceed the curve lev
66. gain to shut off Peak Memory Note The EPOCH LT software allows you to select whether to view the live waveform and or the Peak Memory echo envelope as an outline or a filled in trace Screen Freeze The Screen Freeze function holds or freezes the information on the screen at the moment FREEZE is pressed Once the Freeze function is activated the pulser receiver of the EPOCH LT becomes inactive and does not acquire any further data An F appears to the right of the A Scan display indicating the function is active The Freeze function is useful when storing waveforms as it holds the current A Scan allowing the transducer to be uncoupled from the test material Once the display is frozen you can do a variety of functions such as storage of the waveform or thickness data and entry of an alphanumeric location code or memo to describe the data It is possible to manipulate the gates to obtain thickness or soundpath data The Freeze function differs from Peak Memory in that no new data is acquired and added to the instrument display The FREEZE key is ideal for high temperature measurements When Freeze is active the following parameters cannot be changed accessed e Zero Offset e Range e Zoom e Reject e Gain e Reference Gain e Peak Memory e Pulser Receiver To disable the Freeze function and return to normal operation press FREEZE again 6 1 6 2 Part 910 258 Using the Gates Using the Gates This chapt
67. ghts when activated Use the 4 y lt or key to change an activated parameter value Press the ENTER key multiple times to toggle through the instrument settings To move quickly through the sequence press ENTER multiple times in succession or hold down the key to reach the desired function Direct Access Operation Most commonly used parameters also have their own individual keys to provide direct access to the parameter setting To use the EPOCH LT in this manner press the appropriate key to change the parameter and then either press one of the function keys F1 F5 to select preset values or adjust the value using the 4 y lt 4 and gt slewing keys For example to change the gain press GAIN Press F1 F2 F3 E4 or F5 to select one of the preset dB steps or use the slewing keys for fine adjustments In some cases the parameter appears as a second function above another key To change these parameters press 2nd F and then the appropriate key to access that parameter Whenever a function is opened in the full screen display the EPOCH LT provides prompts in the Abbreviated Status window directly above the A Scan display on the left side Summarizing Keypad Functions The EPOCH LT keypad includes five function keys located directly underneath the display F1 F2 F3 F4 and F5 When an operator accesses a parameter from the lower portion of the keypad preset value choices are
68. has been programmed CONTACT 4DB gt 881_ 4 GAIN 35 2dB RANGE 1 688in 0 801 ID SELECTED MIN DEPTH 8 898 in 100 a 5 3 4 4 80 60 TVG i 2 4 6 8 18 Figure 41 TVG Example When TVG mode is active any parameter that would affect instrument calibration is automatically locked This includes GAIN ZERO OFFSET VELOCITY ANGLE REJECT and all pulser and filter parameters Once the TVG setup is complete you can activate the Reference Gain function by pressing 2 4F GAIN REF DB This locks in a reference gain level and allows scanning gain to be added or subtracted to accommodate specific applications Note that the additional scanning gain cannot be added to the original reference gain level as this would change the calibration and invalidate the TVG setup Saving and Recalling TVG Setups TVG setups are saved and recalled in the same manner as any general waveform calibration With TVG mode active the SAVE WAVE key is used to save the entire 9 3 3 9 4 1 9 4 2 Part 910 258 Using Software Options setup in the datalogger When a setup that was stored with a TVG setup is recalled the instrument automatically comes up in TVG mode Exiting TVG Mode To clear the TVG setup and return to the normal operation follow these steps 1 Press OPTION 2 Use the slewing keys to highlight the TVG selection and press ENTER to go into the TVG setup Us
69. he audience 1 2 3 4 Are the tone and style appropriate for the purpose and audience 1 2 3 4 Is terminology consistent 1 2 3 4 Are grammar syntax spelling and punctuation correct 1 2 3 4 Illustrations Do the illustrations contribute to the usefulness of the document 1 2 3 4 Are the illustrations effectively integrated into the text 1 2 Are the illustrations clearly labelled 1 2 Layout and Design Is the layout effective for the audience and purpose 1 Is the overall design consistent and coherent 1 Overall Document 1 2 3 4 Additional Comments Which topics are not covered that you would like to see covered in the next revision Errors found in this manual Page Description of Error Name Company Mailing Address Phone E Mail Address Fax No On aun Aa A
70. he signal and the echo should jump up and down on the screen Use the Zero Offset to move this echo to the left side of the screen so that it is barely visible 2 Press CAL A Cal symbol will appear to the right of the A Scan signifying the EPOCH LT is in the Auto Calibration mode To exit the Auto Calibration mode at any point press ENTER 3 Couple the transducer to the THIN calibration block step For this example the transducer will be coupled to the 0 100 step 4 Position Gate 1 so that the first backwall echo from the known thickness step is exceeding the gate threshold Adjust the gain setting so that the echo amplitude is approximately 80 A thickness reading appears in large text above the A Scan Note Make sure it is the first backwall echo being gated not a multiple echo from the end of the delay line tip 59 EPOCH LT 60 GAIN 41 88 RANGE 1 688in 0 082 rare 8 PIN DEPTHS Lra in 80 ets tee 6 18 WEL 232B8infus FULLWAYE DATE 09 18 04 ZERO 10 39 us ENERGY LOW TIME 03 09 ANGLE DAMP 5 a DELAY 6 880 in THICK 888 in PULSE ECHO CAL GATE START WIDTH LEVEL ALARM 1 0 071 0 786 432 OFF 2 16 081 6 580 OFF OFF 10 20 0d6 30 0dB 40 0db Figure 21 Calibrating for a Thin Block Using a Delay Line Transducer 5 Press ZERO OFFSET once the reading is steady The screen freezes and a pop up box appears on the screen Use the 4 and slewing keys to enter the exact known thickness of the te
71. if necessary Use the green slewing keys to position the gate over the desired echo Be sure the echo breaks the gate threshold Press F5 The peak of the highest amplitude echo breaking the Gate 1 threshold is brought to 80 screen height DEMO_ __ _ gt 005 GAIN 25 8dB katai 4 00A 1 070 RIARI i PIN DEPTH Hp 869 in 1 START 1 WIDTH LEVEL AU TO 80 Figure11 After Activating AUTO 80 4 3 Part 910 258 Adjusting the Pulser Receiver Note You can use AUTO 80 when an echo exceeds the desired gate threshold The echo can be either above or below 80 full screen height If a signal is above 80 screen height the EPOCH LT reduces gain in a series of repetitions until the signal peaks at 80 Occasionally for very high amplitudes above 500 full screen height you may need to press the F5 key a second time Setting a Gain Reference Level and Adding Scanning Gain To establish the current system gain as the reference base level press 2nd F GAIN REF This is useful for inspections that require you to establish a reference gain level then add or subtract additional scanning gain After accessing the reference function the gain display will read REF XX X dB 0 0 You can now add scanning gain independent of the reference gain level To add scanning gain follow these steps 1 Press F2 to add or subtract scanning gain in 6 dB increments The cursor position is to the left of the decimal poi
72. inches or millimeter values 49 EPOCH LT 6 8 50 HIN D DEPTH 7 835 b 680 Z 4 6 8 10 Y infus FULLWAVE DATE 09 18 04 ZERO 435 us ENERGY MED TIME 08 49 ANGLE 4 DAMP 58 DELAY 8 688 us THICK 6 668 us PULSE ECHO GATE START WIDTH LEVEL ALARM 1 7 098 3 518 16 2 OFF 2 138 63 5 000 OFF 19 8dB 25 8dB 35 8dB 45 806 Figure 14 Time of Flight Mode Displaying us Values To setup the Time of Flight mode follow these steps Use the Setup menu to turn on Time of Flight mode Press OPTION Move the highlight bar over Setup and press ENTER Move the highlight bar over Unit and press ENTER Move the highlight bar over pts Full Scale to viewin units full scale or us DIVISION to view in units per division and press ENTER 6 Press OPTION to return to the live screen ey ke re Using the Zoom Feature To zoom in on an indication position Gate 1 over the area of interest and press 2nd F RANGE ZOOM The instrument automatically uses material delay to bring the point that corresponds to the gate start to the screen s left side and also adjusts the displayed range to match the gate width The new range equals the unzoomed gate width The lowest achievable value of the expanded range is equivalent to the minimum range of the instrument at the current material velocity setting Flaw Detection Zoom is useful in certain flaw detection applications for example in the detection of faceted defects such
73. ing Scanning Gain 39 sA Using the Pulser Key sori e E a e ahd HS EE E E E ONES 40 4 4 1 Waveform Rectification s es eae Mains aye oe Ma ee Beka 40 AAD Pulser Bnerey sya e sade vor ceed eae teed diese dee weet ates 40 445 DAMPING va vigad we haa eae sage ers ae ahate ayaa vk eee 41 LAA TESCMOdE son any tr a a Mae hd arate Hote ad hg gel 41 5 Managing Special Waveform Functions esessssssescsscsseceseseso 43 JA DRETC Ces ory Gey gate hie a aR E Alas Sy giao E Wig L RREA EE 43 5 2 Peak Memory ss ci lower rdscoheeekigoivd ta Gute ni kdaw he ht dette eh 43 5 3 Screen Freeze ya Vee ye Pe ue eA ne ee eae A e wea e 44 6 Using the Gales eee 2 se Sees So Se ON es BS REG 52 ORES LAOREET AE ONG ERE 45 Gul Positionmne Gatel oaea A a ah Pala ra la Sad Mica ah de a a Lees anh 45 62 Positioning Gale 201224 seine wese ila oh one eines eee Gee de as 45 6 3 Making Thickness Readings 5 2 esis nese dead ete bsawar eee ewe e tas 46 6 4 Using the Echo to Echo Software Option 0 00 c eee eee eee 47 6 5 Locating Flaws with an Angle Beam Transducer 0 00005 47 6 6 Measuring Signal Amplitude 0 0 eee eee eee ee 48 6 7 Operating Time of Flight TOF Mode 0 0 ee eee eee eee 49 6 8 Using the Zoom Peaire salts cterov ek ide Bohlen ele eed a hdd dan a Ca ee 50 6 9 Activating Gate Alarms 22 52 2 ediG ea wie epee eee deGNavieweh eae eee s 51 6 9 1 Threshold Alan
74. ion Marketing Dept Technical Publications Thank you for helping us improve our documentation Note The following questionnaire is adapted from the Judging Form from the Boston Chapter Society for Technical Communication Technical Publications Competition and Revision Checklist from John Lannon s Technical Writing Seventh Edition Addison Wesley Longman 1997 Document Title Document Number Documentation Usability Ratings In the sections that follow please rate the usability of the document according to the following rating system 1 Poor 2 BelowAverage 3 Average 4 Above Average 5 Excellent Audience and Purpose Is the purpose of this manual clearly stated 1 2 3 4 Does the document fulfill the purpose 1 2 3 4 Is the audience clearly defined 1 2 3 4 Does the document meet the audience s needs 1 2 3 4 Organization Do the instructions follow the exact sequence of steps 1 2 3 4 Is the organization appropriate and logical at all levels 1 2 3 4 Are the headings specific and helpful 1 2 3 4 Is the Table of Contents complete and useful 1 2 3 4 Content Do explanations enable readers to understand what to do 1 2 3 4 Do notes cautions or warnings appear whenever needed in the appropriate place 1 Is everything accurate 1 aun Aa A n a Aa A Are the main points properly stressed 1 Are there sufficient helpful examples 1 2 3 4 Writing and Editing Is the reading level appropriate to t
75. is equipped with a high resolution distance calculator that provides a direct readout of thickness soundpath or time of flight data across the top of the A Scan Depth measurements can be made in two different ways Some applications may require measuring to the leading edge of the signal while others may require measuring to the peak of the signal To take a thickness reading assuming that the EPOCH LT is properly calibrated See Calibrating the EPOCH LT on page 55 follow these steps 1 Position Gate 1 Because Gate 1 is used to obtain single echo thickness readings it must be positioned correctly To obtain a thickness reading the appropriate echo on the display must exceed the gate threshold Make sure that Gate 1 starts at less than the minimum expected thickness value and that its width exceeds the maximum expected value Note When the gage is used for thickness gaging set Gate 1 level just high enough to avoid false readings When the gage is used for flaw detection set Gate 1 according to appropriate acceptance and rejection criteria 2 Select the Measurement mode The EPOCH LT can measure to either the leading edge or the peak of a signal 3 Press DEPTH AMPLIto select the appropriate mode The following selections will appear in the function boxes below the A Scan display F1 EDGE F2 PEAK F3 AMP F4 TOGGLE The F4 TOGGLE selection only appears when the unit has a refracted angle entered and when either the peak or
76. is triggered whenever the current thickness reading falls below an operator defined level Use the minimum depth alarm with a single gate or in the optional Echo to Echo measurement mode In Echo to Echo mode the cursor appears on the second gate A cursor appears at the bottom of Gate 2 to indicate this level 6 9 3 Minimum Depth Alarm with a Single Gate Minimum depth alarms can be set on Gate 1 and or Gate 2 To set a minimum depth alarm on Gate 1 follow these steps 1 Press GATE 1 and use the start width and level parameters to position the gate over the desired area Be sure the gate start position is set to cover a range below the minimum depth alarm value 2 Press 2nd F GATE 1 ALARM 1 to display the alarm choices in the function boxes at the bottom of the screen Press F3 to activate the minimum depth alarm 3 Use the 4 lt 4 and keys to set the desired minimum value The range of minimum depth values is limited by the gate start and width settings The minimum depth alarm value must be greater than the gate start value and less than the gate width value Once activated a marker appears on the gate to indicate the current setting Any indication that exceeds the gate threshold to the left of the marker will activate the alarm 4 Press 2nd F GATE 1 ALARM 1 and then press F4 to shut off the alarm 52 6 9 4 6 9 5 Part 910 258 Using the Gates Minimum Depth Alarm in the Optional
77. is turned on by pressing GATE 2 and then pressing F4 for ON Threshold Alarms Threshold alarms can be set on Gate 1 and or Gate 2 To set a threshold alarm on Gate 1 follow these steps 1 Press GATE 1 and use the start width and level parameters to position the gate over the desired area 2 Press 2nd F GATE 1 ALARM 1 The alarm choices are displayed in the function boxes at the bottom of the screen 3 Press F1 for positive logic or F2 for negative logic A negative logic alarm indicates a signal is absent from the gate A positive logic alarm indicates a signal is present within the gate Either Gate 1 or Gate 2 can be set positive or negative Once a threshold alarm is activated markers at the starting and ending points of the gate will point upwards or downwards to indicate which type of alarm has been set GAIN 37 8dB RANGE 2 666in EEA EEEE 7 SAINS 3 f 0 697 SSRN IN DEPTH a cos U in 100 a Figure 15 Negative Logic Alarm 51 EPOCH LT Lenape aes Peete eee eels 4 GAIN 37 dB RANGE 2 000in 0 697 GSM MIN DEPTH 6 695 in 100 aN Figure 16 Positive Logic Alarm 4 Press 2nd F GATE 1 ALARM 1 and then press F4 for OFF to shut off the Gate alarm 5 Press 2nd F GATE 2 ALARM 2 and then press F4 for OFF to shut off the Gate 2 alarm 6 9 2 Minimum Depth Alarm The EPOCH LT is equipped with a minimum depth alarm which
78. lay with peak hold reference Freezes and holds waveform and soundpath display Gates and thickness can be adjusted after the display is frozen Negative spike or square wave tunable excitation Selectable Low Medium High or Max Selectable settings of 50 63 150 or 400 ohms Full wave half wave positive or negative and unrectified RF settings Broadband 20 MHz at 3 dB Pulse Echo Dual or Through Transmission Selectable threshold positive negative or Minimum Depth modes Storage of up to 100 waveforms or 2 000 thickness readings Expanded memory to 500 waveforms or 10 000 thickness readings 16 numeric location codes 0 C to 50 C 32 F to 122 F 20 C to 50 C 4 F to 122 F with battery 15 C to 60 C 5 F to 140 F without battery AC Mains 100 120 VAC 200 240 VAC 50 60 Hz Internal rechargeable NiMH battery back 6 8 hours nominal 2 5 hours typical Continuously displayed low battery warning display when battery life falls below one half hour 00 Lemo English or International symbols Keypad selectable English French German Japanese Spanish Italian Russian and user customizable languages available Custom option not active Part 910 258 PORT DIMENSIONS WEIGHT WARRANTY Appendix A Specifications USB 2 0 port for high speed data transmission between the EPOCH LT and a PC 9 375 H x 5 45 W x 1 5 T 2 35 Ibs 1 0 Kg One year warranty batt
79. m display This is a real time condition only and is not stored 3 6 5 3 6 6 3 6 7 Part 910 258 Managing Basic Operations Keypad Lock Functions All Lock Cal Lock When you select All Lock all keys except DISPLAY OPTION ENTER 4 4 4 gt and ON OFF are inactive A full padlock appears above the battery symbol indicator to show that All Lock is selected When you select Cal Lock a half padlock appears above the battery indicator and the following keys are inactive GAIN VEL REJECT CAL ANGLE THICKNESS ZERO OFFSET PULSER FILTER RANGE To unlock either the All Lock or Cal Lock return to the Setup screen and deselect the item Filled Live When you select Filled Live the live waveform appears filled in rather than as an outline trace This is used to make the waveform more visible when viewing in bright sunlight Filled Peak When you select Filled Peak a waveform or echo envelope that is frozen on the screen when using the Peak Memory feature appears filled in rather than as an outline trace 35 EPOCH LT 36 4 1 4 2 Part 910 258 Adjusting the Pulser Receiver Adjusting the Pulser Receiver This chapter describes how to adjust the pulser receiver Topics are as follows e Adjusting System Sensitivity e Using AUTO 80 e Setting Gain Reference Level and Adding Scanning Gain e Using the Pulser Key Adjusting System Sensitivity To adjust th
80. ng keys to highlight Off and press ENTER 4 Press OPTION to return to the A Scan display Time Varied Gain TVG The Time Varied Gain TVG option compensates for the changes in echo amplitude from equal sized reflectors at different distances due to material attenuation and beam spreading When TVG is properly set up equal sized reflectors produce indications of equal screen height regardless of their distance from the transducers TVG has a dynamic range of 40 dB with a minimum echo height of approximately 5 Note the following items when using the TVG option e TVG is active in all display modes RF Full Wave Half Wave and Half Wave e TVG and DAC may not be activated simultaneously e Up to 20 TVG calibration points may be programmed separated by a minimum of 0 52 microseconds approximately 0 06 or 1 5 mm at longitudinal velocity in steel e The minimum full screen range must be set greater than approximately 1 25 mm at longitudinal velocity of steel to activate TVG After a TVG curve is set up it is possible to zoom in to smaller ranges than 1 000 inches e The maximum full screen range must be set less than approximately 120 3050 mm at the longitudinal velocity of steel to activate TVG e TVG must be set up with the aid of reference standards that generate representative echoes at the points of interest Activating and Calibrating TVG To activate and calibrate TVG follow these steps 1 Calibrate the EPO
81. nstrument calibration data To setup the EPOCH LT before calibrating follow these steps 1 Press DISPLAY to select the split screen display 2 Press 2nd F VEL REJECT to set the reject level to 0 Press F1 or use the y slewing key to adjust the value to zero 3 Press GAIN to select an initial gain value that is appropriate for the calibration and adjust the value by using the direct access function keys or the 4 and keys If the appropriate gain level is unknown set the initial gain at 30 dB and adjust it as necessary during calibration 55 EPOCH LT 7 2 56 4 Press VEL to enter an approximate velocity for the test material and adjust the value with the function keys or the 4 and 4 keys If the velocity value is unknown find a Starting value in the velocity in Appendix B of this manual 5 Press RANGE to set the range and then adjust the value using the function keys or the 4 Ly lt or gt keys 6 Press 2nd F ANGLE THICKNESS to set the material thickness to 0 00 or 0 00 mm Press F1 or use the y key to adjust the value to zero 7 Press ZERO OFFSET to set the zero offset value to 0 00 usec Press F1 or use the y or gt keys to bring the initial pulse to the left side of the instrument screen 8 Press ANGLE to enter the correct refracted angle for the probe 0 for a straight beam or 90 probe 45 for a 45 etc Use the function keys to access pres
82. nt 2 Use the 4 and keys to increment or decrement 3 Press F1 to make adjustments in 0 1dB increments The cursor position is to the right of the decimal point 4 Use the 4 and keys to increment or decrement Use the 4 and y keys to increment and decrement the scanning gain Tip Press GAIN multiple times as another method to toggle back and forth between the 6 dB and 0 1 dB increments You can add the scanning gain to the reference level toggle between the active scanning gain and 0 dB this is the scan dB feature or turn it off by pressing the following keys F3 Adds the reference gain and scanning gain together and exits the Reference Level function F4 ScandB Toggles the scanning gain back and forth from the active scanning gain and 0 dB F5 Exits the Reference Level function without adding the entered scanning gain Prompts are displayed in the function boxes at the bottom of the screen If another parameter is accessed these choices may change but can be brought up again by pressing 2nd F GAIN REF 39 EPOCH LT 4 4 4 4 1 40 Using the Pulser Key The following pulser receiver and filter parameters can be adjusted on the EPOCH LT keypad e Waveform Rectification e Pulser Energy e Pulser Damping e Pulser Test Mode To access the available parameters follow these steps 1 Press PULSER multiple times to toggle through the several features 2 Each p
83. o a file you may want to save data to a different file If you return to a file where data has already been saved the ID code displays the next available ID incremented after the last save e To interrupt the auto ID sequencing press the ID key and enter a new ID code The new ID code then increments in the same fashion Note It is possible to create a list of ID s in the Gage View Interface Program and then transmit this list to the instrument When you select this file to save information the unit automatically begins to incrementally fill the ID database created in the PC Contact Panametrics NDT or your local representative for details regarding ordering the Gage View Interface Program Recalling Transducer Calibrations and Waveforms The EPOCH LT datalogger is designed to let you quickly review the contents of saved files and then recall saved transducer calibrations to the live screen To recall a saved calibration follow these steps Press the 2 4F ID to enter the Memory screen Use the slewing keys to select the file where the desired calibration is located When the file is highlighted press F1 to enter the Contents screen To ua Nea Use the slewing keys to scroll through the selected file Only IDs with saved waveform parameter setups can be recalled to the live screen The ID name being 75 EPOCH LT 76 viewed displays at the top of the screen As you scroll through the file this ID will continu
84. odes Pulse Echo Mode Single element transducers Use either connector Through Mode Two separate transducers typically on opposite sides of the test specimen Use the top red connector as the transmitter Dual Mode Pitch and Catch One connector acts as a transmitter while the other acts as areceiver The top red connector is designated as the transmitter To select a Test mode follow these steps 1 Press PULSER to access the Test mode parameter 2 Use the function keys for direct access or the 4 and y keys to toggle through the three selections Note To compensate for the one way soundpath in Through mode the EPOCH LT does not divide transit time by two when calculating thickness measurements 5 1 5 2 Part 910 258 Managing Special Waveform Functions Managing Special Waveform Functions This chapter describes how to manage special waveform functions Topics are as follows e Reject e Peak Memory e Screen Freeze Reject The Reject function eliminates unwanted low level signals from the EPOCH LT s display Because the EPOCH LT features a digital waveform display the reject function is linear Increasing the reject level does not affect the amplitude of the signals above the reject level The reject level is continuously adjustable from 0 to 80 of full scale with 1 resolution and is displayed in the upper left corner of the screen in the split screen view Note It is not possible to
85. on can be activated by pressing 2nd F GAIN REF DB This key sequence locks in a reference gain level and allows scanning gain to be added or subtracted to accommodate specific applications For example if it is required to evaluate any reflector that exceeds 50 of the DAC level 6 dB of scanning gain can be added In this manner the DAC curve when used in conjunction with the Amplitude DAC display and DAC alarm becomes an easy reference to determine if an indication exceeds the evaluation level Note that the additional scanning gain cannot be added to the original reference gain level as this would change the calibration and invalidate the DAC curve Note The Zoom function is active after setting up a DAC curve When zooming in on a particular echo the DAC curve temporarily disappears The curve reappears when zooming back out The A Scan waveform can also be saved when in the Zoom mode however the DAC curve is not saved with the waveform 79 EPOCH LT 9 2 2 9 2 3 9 2 4 80 Special Considerations for JIS Z3060 DAC Curves In general the instructions in Section 9 2 1 apply to the construction of all DAC curves However there are some special provisions that have been made to address the requirements of JIS Z3060 These considerations are listed below Because of the large number of curves drawn for the JIS DAC mode it is possible to temporarily add 6 12 18 or 24 dB of additional gain while constructing the DAC c
86. options The information contained within this manual can be read in modular format to answer questions about how to perform specific functions We suggest reading the entire manual at least once with your instrument in hand so that you can combine reading the descriptions and examples with the actual use of the instrument Audience This document is intended for any operator using the EPOCH LT Panametrics NDT recommends that all operators have a thorough understanding of the principles and limitations of ultrasonic testing We assume no responsibility for incorrect operational procedure or interpretation of test results We recommend that any operator seek adequate training prior to using this equipment While the EPOCH LT is acontinuously self calibrating instrument it is up to the customer to determine regulatory requirements Panametrics NDT offers calibration and documentation services Contact Panametrics NDT or your local representative with any special requests Scope The following table describes the major sections in this document Chapter Description Audience Chapter 2 Describes using different power Operators supply options Also describes the battery operating time battery replacement and battery charging Chapter 3 Describes the EPOCH LT interface Operators and functions such as the keypad screen options screen display and setup parameters Chapter 4 Describes how to adjust the pulser Ope
87. orward and backward until you have peaked up the return signal from the hole that is found the maximum amplitude Tip The Peak Memory feature on the EPOCH LT is an excellent tool to aid in finding the peak of the signal 3 Adjust the system sensitivity Gain up or down once the echo is peaked up to bring the reference reflector signal to a predetermined reference line on the screen In this example the echo is brought to 80 of full screen height 4 Press 2nd F GAIN REF to lock in the reference gain level and add subtract scanning gain separately 5 Press the function keys once the reference gain functions are activated to select between adding or subtracting in 0 1 dB or 6 0 dB increments TE Joe er ee ee 4 REF 49 2 HRANGE 10 009in 1 144 Ww 1 619 1 144 in g 3 4 100 8a 0 1dB 6 AdB Figure 37 Locking the Reference Gain to Add Subtract Scanning Gain 70 8 1 Part 910 258 Managing the Datalogger and Data Communication Features Managing the Datalogger and Data Communication Features This chapter describes how to manage the EPOCH LT datalogger which is designed for ease of use while providing a wide range of features for virtually all flaw detection and thickness gaging requirements It includes the following capabilities e Data organized by file and identifier ID code e Numeric file names and identifier codes e On screen scroll review of fil
88. ource other than the input signal Amplitude Referring to an indication on the CRT screen the vertical height of an indication measured from the lowest to the highest point on the indication In wave motion the maximum displacement of the particles of the material Angle Beam Transducer A transducer that transmits or receives the acoustic energy at an angle to the surface to set up shear waves or surface waves in the part being inspected A Scan Pulse echo format wherein the CRT display shows the pulse travel time in the horizontal direction left to right representing the corresponding sound paths The vertical direction bottom to top displays the maximum value of the acoustic pressure echo amplitude received by the probe Attenuation The loss in acoustic energy that occurs between any two points of travel This loss may be due to absorption reflection or other factors Attenuation M L A The loss of sound pressure in a travelling wavefront caused by the scattering of some of the wave s sound pressure by the grain structure and or porosity of the medium and by absorption a conversion of sound energy into heat Back or Backwall Echo The echo received from the side of the specimen opposite the side to which the transducer is coupled This echo represents the thickness of the specimen at that point Background Noise Extraneous signals caused by sources within the ultrasonic testing syst
89. r energy settings are used for thin materials while the higher settings are used for thicker materials and or highly attenuating materials To select a pulser setting follow these steps 1 Press PULSER to access the energy level settings In the Split Screen mode the pulser energy level is highlighted on the lower half of the screen 2 Use the function keys for direct access or the 4 and y keys to move among the four selections Damping The damping control lets you optimize the waveform shape for high resolution measurements via an internal resistive circuit There are four damping settings e 50ohms e 63 ohms e 150 ohms e 400 ohms Tip Generally the lowest ohm setting increases the system damping and improves near surface resolution while the highest ohm setting decreases system damping and improves the instrument penetration power Selecting the correct damping setting fine tunes the EPOCH LT to operate with a particular transducer selection Depending on the transducer being used the various damping settings either improve near surface resolution or alter the instrument s penetration power To select a damping option follow these steps 1 Press PULSER to access the Damping parameter 2 Use the function keys for direct access or the 4 and y keys to toggle through the four available damping selections 41 EPOCH LT 4 4 4 42 Test Mode The EPOCH LT can operate in three different Test m
90. r relating to frequencies above the human audible range that is above 20 000 cycles sec Hertz Ultrasonics Study of pressure waves which are of the same nature as sound waves but which have frequencies above the human audible limit that is above 20 000 cycles sec Hertz 103 EPOCH LT 104 Term Definition V Path The angular distance sound travels measured from the top surface of the material to the bottom and reflecting back up to the top surface Vertical B The larger length if rectangular of the actual crystal The software will compute the affective length automatically Wavelength The distance between like points on successive wavefronts that is the distance between any two successive particles of the oscillating medium that are in the same phase It is denoted by the Greek letter A lambda Appendix D EPOCH LT Parts List Appendix D EPOCH LT Parts List Part Description EPLT xx EPOCH LT Flaw Detector Table 7 EPOCH LT Ultrasonic Flaw Detector Part Description EPLT BAT NiMH Battery EP4 MCA X Mini Charger Adapter X Power Cord Configuration EPLT CAL NIST NIST Calibration Certificate 36DLP CC Plastic Transport Case 36DLP HAND Hand Strap EPLT MAN Instruction Manual EPLT OS EPOCH LT Operating Software exclusive of the interface program Table 8 Items Included with the EPOCH
91. rators receiver for system sensitivity gain reference level and scanning gain Also describes how to use the pulser keys Chapter 5 Describes using the special Operators waveform functions such as reject peak memory and screen freeze Table 1 Overview to Instruction Manual Part 910 258 Preface Chapter Description Audience Chapter 6 Describes using the available gates and gate alarms Also describes making various thickness readings locating flaws with and angle beam transducer measuring signal amplitude time of flight mode and the zoom feature Operators Chapter 7 Describes calibrating the EPOCH LT with a straight beam delay line dual element and angle beam transducer Also describes how to locate the Beam Index Point verify the refracted angle beam and calibrate for distance and sensitivity Operators Chapter 8 Describes using the datalogger and data communication features such as storage capacity and memory creating new files saving waveforms and thickness readings and increasing ID increments Also describes recalling and saving calibrations and waveforms creating memos and editing a file Operators Chapter 9 Describes various software options for EPOCH LT including Distance Amplitude Correction DAC Time Varied Gain TVG Low Pulse Repetition Frequency PRF Expanded Memory Echo to Echo Measurement Mode AWS Curved Surface Cor
92. rection and Extended Range Operators Appendix A Describes EPOCH LT specifications Operators Appendix B Provides a table of the ultrasonic velocity in a variety of common materials Operators Appendix C Glossary of terms Operators Appendix D Provides the EPOCH LT part list Operators Table 1 Overview to Instruction Manual Continued EPOCH LT 1 5 Typographic Conventions The following notes and table provide a list of the typographic conventions that appear in this document Warning This information indicates danger and the possibility of personal injury Caution This information indicates that equipment damage can occur Note This information provides explanatory information Tip This information provides helpful guidelines for easy operation Convention Description Courier Font Used for file names lines of code names of processes and commands Heavy courier Used for command line user input Bold Used for textual parts of graphical user interface including menu items buttons toolbar names modes options and tabs Italics Used for screen window names dialog boxes and document titles Bold Italics Used for emphasis Bold Square Brackets with Used for instrument keys on the keypad Bold lt Italics gt Angle Brackets With italics text used for variable data gt Used for showing the next sequential st
93. rm Appendix C Glossary Definition Sound Beam The characteristic shape of the ultrasonic wave sent into the material Sound Path Distance The distance from the transducer beam index point to the reflector located in the specimen measured along the actual path that the sound travels Sometimes referred to as angular distance in angle beam testing Straight Beam Probe A probe that transmits the sound into the material Normal Beam Probe perpendicular to the entry surface Surface Wave Mode of wave propagation characterized by an elliptical movement of the particles molecules on the surface of the specimen as the wavefront moves forward this movement penetrating the specimen to a depth of one wavelength Through Transmission A test method in which the vibrations emitted by one search unit are directed toward and received by another search unit The ratio between quantity of vibration sent and received is a measure of the integrity or quality of the material being tested Time Varied Gain TVG Circuit that automatically adjusts gain so that the echo amplitude of a given size reflector is displayed at a constant screen height regardless of the distance to that given size reflector Transducer A device that transforms one form of energy into another Transmitter Circuit of the flaw detector that sends the initial pulse voltage to both the transducer and receiver Ultrasonic Of o
94. rmal for NiMH batteries Replacing the Battery Warning The EPOCH LT Charger Adapter is designed to charge EPOCH LT batteries only DO NOT ATTEMPT TO CHARGE ANY OTHER BATTERIES Doing so may cause an explosion and injury Do not attempt to charge other electronic equipment This will cause permanent damage To replace the battery follow these steps 1 Turn the unit over so the display is face down 2 Loosen the four screws on the back of the unit at the bottom that secure the battery door cover 3 Remove the battery door cover exposing the battery 4 Remove the battery pack 5 Unclip the battery lead 6 Install the replacement battery by reversing these steps Charging the Battery Note Charge EPOCH LT batteries with the Charger Adapter only There is no on off or line voltage selector switch The Charger Adapter automatically turns on when AC power is applied You can charge the EPOCH LT battery either internally in the unit or externally using a stand alone charging base To charge the battery internally follow these steps 1 Plug the Charger Adapter into an AC main line 2 Plug the output cable directly into the receptacle on the top of the EPOCH LT Turn off the EPOCH LT when charging batteries to ensure a complete charge If the EPOCH LT is powered on while connected to an AC line the battery will continue charging at a slower rate When the unit is powered on and connected to the charger the battery s
95. rsal AC power input so it operates with any line voltage from 100 120 or 200 240 volts AC and with 50 to 60 Hz line frequency To use AC line power follow these steps 1 Connect the power cord to the Charger Adapter unit and to an appropriate line power source 2 Connect the DC output power cable from the Charger Adapter unit to the Charger AC adapter input jack on the top of the EPOCH LT Turn the EPOCH LT on via the front keypad 4 Proceed with normal operation Using Battery Power The Panametric NDT EPOCH LT uses Nickel Metal Hydride NiMH batteries Press ON OFF to power up the unit After the initial status screen the EPOCH LT proceeds to the split screen display A battery symbol is always present at the bottom right of the display and indicates the remaining battery charge A completely filled battery symbol relates directly to the charge remaining on the battery A symbol that is half filled means that the battery is 50 charged All batteries show some rebound effects so the initial reading appears higher than the actual amount this is temporary A stable battery reading appears after operating for 1 2 minutes Operating Time for the Battery The EPOCH LT has a nominal operating time of 6 8 hours on a full charge EPOCH LT 2 4 2 5 16 Note It may initially take several cycles of complete charging and discharging of the battery to bring the battery to full capacity This conditioning process is no
96. ry once you have peaked up the signal Note the degree mark on the block that lines up with the BIP which you marked on the side of the wedge in the previous step This is the actual refracted angle Beta for this particular transducer and wedge in steel If this value for Beta differs from the value entered previously enter the corrected angle now via the ANGLE key and the 4 y 4 and gt keys Calibrating for Distance Note This step differs depending on which type of IIW calibration block is used The ASTM E 164 IIW Type I Block which has a crescent cut in the side produces echoes at 4 100 mm and 9 225 mm on the screen The U S Air Force IIW Type II Block which has a large cutout in the side produces echoes at 2 and 4 on the screen The procedure below uses Panametrics NDT IIW Type I carbon steel calibration block part number TB7541 1 We recommend that the EPOCH LT s Range parameter be set to 10 250 mm for this step Regardless of whether a Type I or Type II Calibration block is used this should ensure that the echoes from the block are visible on screen To calibrate for distance follow these steps 1 Couple the probe to the block so that the BIP is directly over the 0 mark on the ASTM test block or the Air Force block Do not move the transducer from this point during this step Press CAL A Cal symbol appears to the right of the A Scan signifying the EPOCH LTis in Auto Cali
97. s h0caie debe eee ed pte oa ea od pees 51 6 9 2 Minimum Depth Alarm 00 2 cece ee eee eee 52 6 9 3 Minimum Depth Alarm with a Single Gate 0 52 6 9 4 Minimum Depth Alarm in the Optional Echo to Echo Mode 53 6 9 5 Alarm Condition Storage a5 feeds ioe nheuc ine ds obemnwa bens 53 7 Calibrating the EPOCH LT ssssssssssssssesesesescesesesesesoeoeo 55 Jel Getting Started sies a aa e eee AE E E he E E ar eae 55 7 2 Calibrating with a Straight Beam Transducer 0 00000 000 56 7 3 Calibrating with a Delay Line Transducer 0 0 0 0 e ee eee 59 7 4 Calibrating with a Dual Element Transducer 0 0 0 0 00 000 62 7 5 Calibrating with an Angle Beam Transducer 0 00 e eee eee 64 7 5 1 Locating the Beam Index Point B LP 20008 65 7 5 2 Verifying the Refracted Angle Beta 00 0000 66 7 5 3 Calibrating for Distance lt 0 2 56 hse we deen vee boos ad eee 67 7 5 4 Calibrating for Sensitivity ov v4 ohare ee Oe 69 Table of Contents 8 Managing the Datalogger and Data Communication Features 71 8 1 Defining the Datalogger Storage Capacity 2 0 cee eee eee eee 71 8 2 Using the Memory Screen 6 4 4 s2 cnahidd ean oho aye cade wages Beds 12 8 3 Entering Numeric File Names and ID Codes 0 00000 73 8 4 Creating Files and ID Codes 20 0 eee nee 73
98. smaller reflector and a signal with higher amplitude may indicate a larger reflector than the reference standard Press DEPTH AMPL and then F3 to display a direct on screen readout of amplitude information 48 6 7 Part 910 258 Using the Gates If an echo exceeds the gate threshold and the EPOCH LT is in the Amplitude mode the amplitude information for that echo is displayed as a percentage of full screen height as both Current Amp and Amp Max GAIN 33 4d8 RANGE 2 000in _ ZAMP SELECTED CURRENT AMP 69 AMP MAK 71 Ba i ip 66 P EE SEREA Figure 13 Amplitude Mode Displaying Current Amp and Amp Max Current refers to the real time percentage of screen height of the highest amplitude signal within the gate The Amplitude Max display retains the highest amplitude of a signal that has broken the gate threshold If a higher amplitude signal is read the Amplitude Max value is updated Reset the maximum amplitude value by pressing any one of the red gate keys If there is no echo within the gate Current will read indicating no reading was taken Operating Time of Flight TOF Mode The EPOCH LT is capable of displaying Time of Flight TOF soundpath data for an echo that breaks the gate Time of Flight is the location of the reflector in terms of microseconds us When the Time of Flight mode is turned on all EPOCH LT distance parameters are displayed using us values instead of
99. ss is exactly the same except that the entries below will be in millimeters rather than inches Locating the Beam Index Point B 1 P To locate the BIP follow these steps 1 Couple the probe to the test block at the O mark IW TYPE 1 REFERENCE BLOCK Figure 29 Reference Block Displaying the 0 Mark 2 Manipulate the probe until a high amplitude signal appears on the screen after the Main Bang This is the reflection from the large arc of the block that is located on the Type I block at 4 100 mm 3 Move the probe forward and backward to bring the echo to its maximum amplitude peak it up Make sure the echoes do not exceed 100 Reduce the Gain setting if necessary Note The Peak Memory feature on the EPOCH LT is an excellent tool to aid in finding the BIP Press PEAK MEM to turn on the feature This feature draws and collects the echo envelope of the signal while also drawing the 65 EPOCH LT 7 5 2 66 live waveform Match the live waveform with the maximum point corresponding to the previously accumulated echo dynamic curve Refer to the figure above for a detailed schematic of using the Peak Memory feature to find the BIP Press PEAK MEM again to turn off the feature gt MRANGE 18 688in MIN DEPTH 8 888 8 18 VEL 1288in us FULLWAVE DATE 89 18 64 ZERO 3 437 us ENERGY MED TIME 09 31 ANGLE 4 DAMP 5 DELAY 688 in THICK 6 688 in PULSE ECHO GATE START WIDTH LEVEL ALARM 1 0 805
100. st sample ENTER VALUE FOR THIN STANDARD 000 10 Figure 22 Entering a Thin Standard Value 6 Press CAL The display returns to the live A Scan Couple the transducer to the THICK calibration block step For this example the transducer is coupled to the 0 500 step 7 Position Gate 1 so that the first backwall echo from the known thickness step is exceeding the gate threshold Adjust the gain setting so that the echo amplitude is approximately 80 A thickness reading appears in large text above the A Scan Calibrating the EPOCH LT bA 42 6 mance 1 688in 0 481 F uih DERIS a os in 2 4 6 8 10 VEL 2328infus FULLWAVE DATE 89 18 84 ZERO 18 39 us ENERGY LOW TIME 09 10 ANGLE 4 8 DAMP 5 DELAY 688 in THICK 6 666 in PULSE ECHO CAL GATE START WIDTH LEVEL ALARM 1 0 071 8 786 43 2 Z 16 681 6 588 OFF 1H AdB AdE Figure23 Calibrating for a Thick Block Using a Delay Line Transducer 8 Press VEL once the reading is steady The screen freezes and a pop up box appears again on the screen Use the 4 and 4 slewing keys to enter the exact known thickness of the test sample ENTER VALUE FOR THICK STANDARD 000 50 Figure 24 Entering a Thick Standard Value 9 Press ENTER to complete the Auto Calibration The Zero Offset and Velocity parameters adjust automatically and the correct thickness reading of any gated echo is displayed on the screen Note It is possible to use Auto Calibration on
101. t completely eliminated in the Peak Depth mode but they are greatly reduced If Peak Depth is selected perform calibrations using the peak of the signal However when using a dual transducer due to the jagged peaks we recommend you use Edge Depth Using the Echo to Echo Software Option Using this Echo to Echo software option you can make measurements between successive echoes Measurements can be made between two consecutive backwall echoes or between an interface echo and any other selected signal in which you can measure thickness through coatings or perform low speed immersion testing Locating Flaws with an Angle Beam Transducer During an angle beam inspection you can obtain accurate and reliable soundpath information using the EPOCH LT s high resolution distance calculator If a refracted angle is entered into the EPOCH LT and an echo is exceeding the gate threshold all angular soundpath components are displayed at the top of the A Scan display GAIN 67 6dB RANGES 254 68mm a34 1 a bE 61535 40 9 2 4 6 8 10 VEL 3127 m s FULLHWAYE DATE 09 18 04 ZERO 7 814 us ENERGY MED TIME 08 41 ANGLE 7 DAMP 58 DELAY 8 688 mm THICK 4 68 mm PULSE ECHO GATE START WIDTH LEVEL ALARM 1 62 111 74 762 37 2 OFF 2 216 73 7 817 OFF OFF 19 8dB 25 8dB 35 8dB 45 806 Figure 12 Angle Beam Inspection 47 EPOCH LT These symbols represent the following distances N angular soundpath distance to the reflector urface
102. tector The EPOCH LT has been designed with the inspector in mind and the instrument has been developed with the features that are needed for common flaw detection applications Features include e New Liquid Crystal Display LCD with backlight for exceptional indoor and outdoor visibility 60 Hz update rate for scanning and long battery life e Array of software options including DAC TVG AWS DGS AVG Low PRF Curved Surface Correction Expanded Memory Extended Range and Echo to Echo measurement e Negative Spike Pulser and 20 MHz broadband receiver for high performance and simple instrument setup e Numeric Datalogger with storage of up to 100 waveforms calibrations and 2000 thickness measurements 500 10 000 with Expanded Memory option These files can be conveniently saved using numeric entries and viewed in the EPOCH LT s datalogger screen or on a PC using the Gage View Interface Program EPOCH LT files are also fully compatible with the EPOCH 4PLUS EPOCH 4 and EPOCH 4B flaw detectors About This Document This document is the Instruction Manual for the EPOCH LT The Instruction Manual describes routine tasks for operating the EPOCH LT These tasks include operating the power supply managing basic operations adjusting the Pulser Receiver managing EPOCH LT 1 3 1 4 10 special waveform functions using the gates calibrating the EPOCH LT managing the datalogger and data communication features and using software
103. tely 80 Part 910 258 57 EPOCH LT 58 0 547 4 9 2 4 6 8 18 VEL 2383in us FULLWAVE DATE 89 18 04 ZERO 6 608 us ENERGY LOW TIME 09 00 ANGLE 4 8 DAMP 5 a DELAY 8 688 in THICK 6 6868 in PULSE ECHO CAL GATE START WIDTH LEVEL ALARM 1 164 8 781 43 2 OFF 2 15 962 6 576 OFF OFF 8 26 6dB 38 8dB 468 808 Figure 19 Calibrating for a Thick Block Using a Straight Beam Transducer 8 A thickness reading appears in large text above the A Scan Once a steady reading is achieved press VEL The screen freezes and a pop up box appears again on the screen Use the 4 and slewing keys to enter the exact known thickness of the test sample ENTER VALUE FOR THICK STANDARD 000 50 Figure 20 Entering a Thick Standard Value 9 Press ENTER to complete the Auto Calibration The Zero Offset and Velocity parameters adjust automatically and the correct thickness reading of any gated echo displays on the screen Note It is possible to use the Auto Calibration feature on a single test block of known thickness You can use multiple backwall echoes instead of coupling on both a thin step and a thick step You can leave the transducer coupled on the thin step move the gate over to one of the multiple backwall echoes and enter the correct soundpath thickness 2 3 4 etc multiple of the first backwall echo during the velocity portion of the calibration 7 3 Part 910 258 Calibrating the EPOCH LT
104. the date and time 73 EPOCH LT 8 5 74 Once the file name is created press DISPLAY to return to the live screen Whatever file is open designated by a flashing cursor is the file that begins to have data saved to it when returning to the live A Scan The file name displays continually at the top left screen Before any data is stored in the file press ID to enter the first Identification ID code A cursor appears at the ID entry line at the top right side of the screen Use the slewing keys or the function keys to enter the ID To redo an entry use the left arrow key to backspace or press ID a second time and a blank line will appear To toggle back to the original ID press ID again Saving Waveforms and Thickness Readings Follow the steps outlined in Section 8 4 to setup a file name in the Memory screen and an Identifier ID file in the live screen The EPOCH LT can save two types of data e Thickness Readings Press SAVE THICK to save the ID code along with the displayed depth amplitude or TOF value The waveform and the setup parameters will NOT be saved during this process and these Ds CANNOT be recalled to the live screen Saving this limited data allows the EPOCH LT to store a larger number of individual IDs and corresponding measurement values 2 000 readings or 10 000 readings with the Expanded Memory option e Waveforms Press SAVE WAVE to save all waveform data and setup parameters in the datalogg
105. tric crystal Decibel 98 A unit which compares levels of power Two power levels P1 and P2 are said to differ by n decibels when P n 10 logio P This unit is often used to express sound intensity In this case P2 is the intensity of the sound under consideration and P1 is the intensity of some reference level In the case of the displayed voltages on a cathode ray tube screen the relationship becomes n 20 logov Part 910 258 Appendix C Glossary Term Definition Delay Control Subcircuit of the sweep generator that allows a variably adjustable time period from the sending of the trigger pulse to the start of the sweep across the CRT Detectability The ability of a test system instrument and transducer to detect a given size reflector Distance Amplitude A method of flaw evaluation that uses a test block with Correction DAC a known size reflector at varying known distances from the transducer This allows you to plot a curve on the CRT screen that represents the amplitude of that size reflector throughout a given distance range This curve shows loss of energy due to beam spreading and attenuation Dual Element Probe A probe containing two piezoelectric elements one that transmits and one that receives Dynamic Range The ratio of maximum to minimum reflective areas that can be distinguished on the cathode ray tube usually based on decibel ratios Electronic Zero
106. tting LCD Backlight Y ou can select to have the LCD backlight display light set on or off The default setting for the backlight is OFF LCD Contrast Depending on sunlight conditions and temperature you may need to adjust the contrast of the LCD to maximize screen visibility You can slew through a wide range of adjustments to optimize the display EPOCH LT 3 2 3 2 1 3 2 2 3 3 20 Using the Keypad The most commonly used keys on the keypad Gain Freeze Save Enter and slewing keys are close to your left thumb All instrument settings can be changed while keeping the left hand in a natural position The keypad is grouped and color coded according to function The outlined section of yellow keys on the left side of the keypad is used primarily for calibrating The separate group of grey keys on top are the function keys designed to provide easy access to preset parameter values The EPOCH LT also has extensive data storage features controlled by the datalogger keys at the right side of the keypad Enter Key While you can access most functions directly via the instrument keypad you can change all essential ultrasonic controls by using the ENTER key and one of the four green slewing keys 4 y lt and gt This method provides control of virtually all instrument settings with the thumb of the left hand Multiple presses of ENTER will toggle through each of the instrument parameters The parameter highli
107. u to easily create and recall transducer calibrations since each file can contain only one setup Files 10 500 are flexible files which can store numerous thickness readings waveforms and memos Thickness readings and waveform data can coexist in the same file Calibration waveform parameter setups can also be stored in these files and recalled to the live screen Using the Memory Screen To enter the Memory screen press 2 9F ID The Memory screen is split into two windows e Lower window displays a directory of files e Upper window displays the file contents To toggle between the two windows press F1 Other function key prompts appear when applicable The remaining available memory is displayed between the File Content and File Directory windows Press F5 to exit and return to the live screen File Content Window XE ME File Directory Window fem co CO u Figure 38 Memory Screen no stored files 8 3 8 4 Part 910 258 Managing the Datalogger and Data Communication Features Entering Numeric File Names and ID Codes You can use the EPOCH LT datalogger for thorough documentation of inspection data Enter a filename along with the date and time for each file to organize inspection data Also you can enter up to a 16 digit identifier string for each saved waveform or thickness measurement To enter numbers follow these steps 1 Use the up and down arrows to enter the numbers 0
108. ulser receiver and filter characteristic adjustments can be done in either full A Scan or Split Screen e In the full A scan the current parameter being adjusted appears at the top left of the screen directly above the waveform e In the Split Screen mode the parameter is highlighted on the lower half of the EPOCH LT screen Note For reviewing the adjustments in this manual we use the Split Screen mode To view how the selections of the pulser receiver affect a waveform couple a transducer to a sample or test block which produces an echo on the top half of the screen Waveform Rectification The EPOCH LT can operate in one of four rectification modes e Full Wave e Half Wave Positive e Half Wave Negative e RF unrectified The RF mode is not active while operating in DAC or TVG mode Peak Memory or Echo to Echo mode To select a waveform rectification mode follow these steps 1 Press PULSER once to display the current screen rectification This is highlighted and displayed at the bottom of the screen 2 Use the function keys for direct access or the 4 and 4 keys to toggle through the different waveform rectification modes 4 4 2 4 4 3 Part 910 258 Adjusting the Pulser Receiver Pulser Energy The EPOCH LT has four pulser energy settings depending upon test conditions e Low 100 v 20 e Medium 200 v 20 e High 300 v 20 e Max 400 v 20 Tip Generally the lower pulse
109. ured from the normal to the reflected sound beam Registration The minimum detectable flaw size Reject Control Also known as suppression it limits the input sensitivity of the amplifier in the receiver Grass or scattering noise can be reduced or eliminated from the screen by its use On most analog instruments it also destroys the vertical linearity relationship between echo heights Resolution The ability of the test system instrument and transducer to distinguish reflectors at slightly different depths Scanning Level The number of dBs of calibrated gain above the reference level added to insure seeing potentially significant reflectors at the end of the V path in a weld inspection Second Critical Angle The minimum incident angle in the first medium at which the refracted shear wave leaves the body of the test specimen Sensitivity The ability of the test system instrument and transducer to detect a given size reflector at a given distance Signal to Noise Ratio The ratio of amplitudes and indications from the smallest defect considered significant and those caused by random factors such as grain scattering or instrument noise Single Element Probe A probe containing only one piezoelectric element which is used to both transmit and receive sound Skip Distance In angle beam testing the surface distance that represents one V path of sound in the material Te
110. urve set The purpose of this feature is to facilitate construction of additional curves when testing at longer ranges Once construction of the curve set has begun add up to 24 dB of additional gain through repeated presses of the GAIN key In order to make clear that gain has been added while constructing the curve the gain appears as follows GAIN 46 2 dB 6 GAIN 46 2 dB 12 etc Once the curve set is completed the gain is reset to its original level 46 2 dB in this example e It is possible to change Angle Material Thickness Zero Offset and Gain in the normal manner when in the JIS DAC mode Be careful when adjusting these parameters to ensure that the relationship of DAC curves to material thickness or distance is not unintentionally altered e Any of the six curves can be used to trip the alarm when in the JIS DAC mode Additionally you can set the alarm to positive or negative To select which curve will be used as the alarm reference level first activate JIS DAC and then use the F4 and F5 function keys to select which curve to use for the alarm threshold The selected curve appears as a double thickness line Once a curve has been selected an alarm can be activated and set to be either positive or negative threshold detection by pressing 2nd F GATE 1 ALARM 1 and following the prompts e When the JIS DAC mode is active the amplitude level of a gated signal is always displayed as a percentage DAC or d
111. usted accordingly when using an angle beam probe to inspect the circumference of the curved surface 85 EPOCH LT 9 9 86 1 Press OPTION 2 Use the slewing keys to highlight CSC from the menu and press ENTER An KX appears indicating that the CSC option is active A cursor will appear over the outer diameter value Use the slewing keys to enter the desired diameter 4 Press F1 and then OPTION to return to the live screen ACSC promptis displayed to the right of the A Scan whenever the EPOCH LT is in CSC mode 5 Calibrate the EPOCH LT and be sure to enter the appropriate shear wave angle Correct soundpath information is displayed when an echo breaks a gate Note The CSC option is linked to the EPOCH LT memory If a calibration or waveform is saved in CSC mode the instrument will be in CSC mode when that data set is recalled A c is displayed in the Memory screen after the ID to signify the calibration or waveform was saved in CSC mode Press OPTION and highlight CSC to exit CSC mode Press ENTER to bring up the CSC setup menu Press ENTER to disable the option and deselect the check box OP Os E A Press F1 to return to the Option menu AWS D1 1 D1 5 The AWS D1 1 D1 5 software option for the EPOCH LT assists with performing inspections covered under the American Welding Society D1 1 Structural Welding Code for steel This code provides inspectors with a method to classify discontinuities found
112. ve occurred during shipment Notify the carrier making the delivery immediately of any damage since the carrier is normally liable for damage in shipment Preserve packing materials waybills and other shipping documentation in order to establish damage claims After notifying the carrier contact Olympus NDT so that we may assist in the damage claims and provide replacement equipment if necessary Your shipping container is re usable and may be used in the future when returning the unit for recalibration or repair Olympus NDT guarantees the EPOCH LT to be free from defects in materials and workmanship for a period of one year twelve months from date of shipment This warranty only covers equipment that has been used in a proper manner as described in this instruction manual and has not been subjected to excessive abuse attempted unauthorized repair or modification DURING THIS WARRANTY PERIOD Olympus NDT LIABILITY IS STRICTLY LIMITED TO REPAIR OR REPLACEMENT OF A DEFECTIVE UNIT ATITS OPTION Olympus NDT does not warrant the EPOCH LT to be suitable of intended use or fitness for any particular application or purpose Olympus NDT accepts no liability for consequential or incidental damages including damage to property and or personal injury In addition to our standard one year warranty Olympus NDT also offers an optional two year warranty call for further details This warranty does not include transducers transducer cables or battery
113. vision Disregard this echo as it is usually the result of beam 7 5 4 Part 910 258 Calibrating the EPOCH LT spreading and sound bouncing off the side of the block Make sure Gate 1 is not over this echo 2 VEL 1288in us ZER 3 437 us ANGLE 0 0 THICK 6 668 in GATE START 1 8 789 2 8 872 AdB Figure34 Adjusting the Gain 4 6 8 18 FULLWAVE DATE 89 18 64 ENERGY MED TIME 09 37 DAMP 5 DELAY 4 888 in PULSE ECHO CAL WIDTH LEVEL ALARM 1 523 192 4 328 OFF 8 Press VEL once the reading is steady The screen freezes and a pop up box appears again on the screen Use the 4 and slewing keys to enter the exact known thickness of the test sample ENTER VALUE FOR THICK STANDARD 009 001 Figure 35 Entering a Thick Standard Value 9 Press ENTER to complete the Auto Calibration The Zero Offset and Velocity parameters adjust automatically and the correct soundpath readings of any gated echoes are displayed on the screen Calibrating for Sensitivity The final step in the angle beam calibration is to calibrate for sensitivity This lets you set up areference gain level 1 Couple the probe to the IIW calibration block so that the transducer is aimed at the 0 060 diameter side drilled hole which is used as a reference reflector 69 EPOCH LT 2 INV TYPE 1 REFERENCE BLOCK Figure 36 IIW Calibration Block with 0 060 Diameter Drilled Hole 2 Move the probe f
114. y of the _ refracted angle of sound energy in atest piece when using angle beam transducers Use the function keys to select preset values and the slewing keys to fine tune this setting White Thickness Allows the entry of material thickness for the test piece when using angle beam transducers THICKNESS TH Use the function keys to select preset Yellow values and the slewing keys to fine tune this setting Table 3 Keypad Functions Continued 25 EPOCH LT English Int Color Function Blue ID Entry Allows entry of an ID Identifier location code This ID could be a new location code or a current one Blue Open Datalogger Opens the EPOCH LT datalogger memory screen White Option This menu allows the user to OPTION access the EPOCH LT s main setup menu This menu contains selections for language units software functions etc Pressing the OPTION key again exits the menu and returns the EPOCH LT to the live screen Green ON OFF Turns the EPOCH LT on or off N e Table 3 Keypad Functions Continued 26 Managing Basic Operations 3 4 Editable Parameters Software The Editable Parameters feature lets you customize some of the values that appear above the F1 to F5 keys These are the values that the EPOCH LT recalls automatically when the corresponding F key is pressed You can edit the following parameters Gain Reject Zero Offset Angle Frequ
115. ymbol on the display will continuously cycle from empty to full to indicate the battery is charging Once the battery reaches approximately 85 capacity the symbol will stop cycling and remain full Part 910 258 Operating the Power Supply 3 Charge the unit for another hour after it reaches 85 capacity in order to achieve full capacity You can also charge the EPOCH LT battery outside the instrument using an external stand alone charger This option is available through Panametrics NDT If the battery is used daily or frequently connect it to the charger adapter when not in use Whenever possible the battery should remain connected to the charger adapter overnight or over a weekend so that it achieves 100 of full charge The battery must reach full charge on a regular basis for the proper capacity and cycle life maintenance Recharge discharged batteries as soon as possible after use Give a full recharge as described above Note Never place discharged batteries in storage without the batteries having received a full recharge Store batteries in a cool dry environment Avoid long term storage under sunlight or in other excessively hot places such as an automobile trunk While in storage fully recharge batteries at least once every two 2 months EPOCH LT 18 3 1 Part 910 258 Managing Basic Operations Managing Basic Operations This chapter describes how to get started with basic EPOCH LT operations

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