Dakota Digital MMX-6 manuel d'utilisation

OPERATION MANUAL DAKOTA ULTRASONICS MMX-6 DL MULTI-MODE ULTRASONIC THICKNESS GAUGE P/N P-143-0002 Rev 1.05 , SEPT. 2002[...]

Dakota Ultrasonics Copyright  2002 Dakota Ultrasonic s. All rights reserved. No part of this publication may be reproduced, translated into another language, stored in a retrie val system, or transmitted in any form or by any means; electronic, mechanical, photocopying, recording, or otherwise, without the prior written consent of Dakota Ultraso[...]

MMX-6 DL Ultrasonic Thickness Gauge CONTENTS I NTRODUCTION O PERATION T HE K EYPAD T HE D ISPLAY T HE T RANSDUCER M AKING M EASUREMENT S C ONDITION AND P REPARATION OF S URF ACES P ROBE Z ERO C ALIBRATION U NITS , B ACKLIGHT , S CAN M ODE , A LARM M ODE , D UAL - M ULTI M ODE , B EEPER , RS232 P ORT & D ATA L OGGER T RANSDUCER S ELECTION A PPEN[...]

Dakota Ultrasonics DISCLAIMER – Very Important! Inherent in ultrasonic thickness meas urement is the po ssibility that the instrument will use the se cond rather than the first echo from the back surface of the material being measure d while in standard pulse-echo mode. This may result in a thickness readi ng that is TWICE what it should be. In a[...]

MMX-6 DL Ultrasonic Thickness Gauge 1 INTRODUCTION The Dakota Ultrasonics model MMX- 6 DL is a precision Ultrasonic Micrometer. Based on the same oper ating principles as SONAR, the MMX-6 DL is capable of measuring the thic kness of various materials with accuracy as high as ± 0.001 inches, or ± 0.01 millimeters. The principle advantage of ultras[...]

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MMX-6 DL Ultrasonic Thickness Gauge 3 OPERATION The MMX-6 DL interacts with the operator through the membrane keypad and the LCD display. The functions of the various keys on the keypad are detailed below, followed by an explanation of t he display and its various symbols. The Keypad This key is used to turn the MMX- 6 DL on and off. When the tool [...]

Dakota Ultrasonics 4 The PRB-0 key is used to "zero" the MMX-6 D L in much the same way that a mechanical micrometer is zeroed. If the tool is not zeroed correctly, all of the measurements that the tool makes may be in error by some fixed value. Refer to page 14 for an expl anation of this important procedure. The CAL key is used to enter[...]

MMX-6 DL Ultrasonic Thickness Gauge 5 The UP arrow key has three functions. When the MMX-6 DL is in calibration mode, this key is used to increase numeric values on the display. An auto-repeat function is built in, so that when the key is held down, numeric values will in crement at an increasi ng rate. When MODE is activated, the UP arrow key scro[...]

Dakota Ultrasonics 6 The MEM key enables/disables the data logging feature of the MMX-6 DL. This key is used in conjun ction with the UP/DOWN arrows, SEND, AND CLR keys (hi-lighted in green). The combination of these keys control the data loggi ng features of the MMX- 6 D L . Re fer to the section on data logging page 28. The CLR key is specificall[...]

MMX-6 DL Ultrasonic Thickness Gauge 7 The Display The numeric portion of the display consists of 4 complete digits preceded by a leading "1", and is used to display numeric values, as well as occasional simple words, to indi cate the status of various settings. When the MMX-6 DL is displaying thickness measurements, the display will hold [...]

Dakota Ultrasonics 8 When the IN symbol is on, the MMX - 6 D L is displaying a thickness value in inches. The maximum thick ness that can be displayed is 19.999 inches. When the MM symbol is on, the MMX- 6 DL is displaying a thickness value in millimeters. If t he displayed thickness e xceeds 199.99 millimeters, the decimal point will shift automat[...]

MMX-6 DL Ultrasonic Thickness Gauge 9 When the + symbol is on and blinking , this indicates that the MMX- 6 D L is currently operating in echo-echo ( Thru-paint/coating ) mode .[...]

Dakota Ultrasonics 10 The Transducer The transducer is the " business end" of the MMX- 6 D L . It transmits and receives ultrasonic sound waves that the MMX-6 D L uses to calculate the thickness of the material being measured. The tran sducer connects to the MMX-6 DL via the attached cable, and two coaxial connectors. When using transduce[...]

MMX-6 DL Ultrasonic Thickness Gauge 11 This is a top view of a typical transd ucer. Press against the top with the thumb or index finger to hold the transd ucer in place. Moderate pressure is sufficient, as it is only necessary to keep the transducer st ationary, and the wearface seated flat against the surf ace of the material being measured. Maki[...]

Dakota Ultrasonics 12 If the Stability Indicator has fewer than five bars darkened, or the numbers on the display seem erratic, fi rst check to make sure that there is an adequate film of couplant beneat h the transducer, and that the transducer is seated flat against the ma terial. If the condition persists, it may be necessary to select a differe[...]

MMX-6 DL Ultrasonic Thickness Gauge 13 Condition and Preparation of Surfaces In any ultrasonic measurement scenario, the s hape and roughness of the test surface are of paramount importance. Rough, uneven surfaces may limit the penetration of ultras ound through the materi al, and result in unstable, and therefore unreliable, measurements. The surf[...]

Dakota Ultrasonics 14 Probe Zero Setting the Zero Point of the MMX- 6 DL is important for the same reason that setting the zero on a mech anical micrometer is important. If the tool is not "zeroed" correctly, a ll of the measurements the tool makes will be in error by some fixed number. When the MMX- 6 D L is "z eroed", this fix[...]

MMX-6 DL Ultrasonic Thickness Gauge 15 6) While the transducer is firmly c oupled to the probe -disc, press the PRB-0 key on the keypad. The MMX- 6 DL will display "Prb0" while it is calculating its zero point. 7) Remove the transducer from the probe-disc. At this point, the MMX-6 DL has successfully calculated it's internal error fa[...]

Dakota Ultrasonics 16 calibration is the simplest and most commonly used calibration procedure - optimizing linearity over large ranges. The two point calibration allows for greater accuracy over small ranges by calculating the probe zero and velocity. The MMX-6 DL provides three simple methods for setting the sound-velocity, described in the follo[...]

MMX-6 DL Ultrasonic Thickness Gauge 17 Calibration to a known thickness Note: This procedure requires a sample piece of the specific material to be measured, the exact thicknes s of which is known, e.g. from having been measured by some other means. 1) 1) Make sure the MMX-6 DL is on and switched to P-E (pulse- echo) mode. Press the Dual-Multi key [...]

Dakota Ultrasonics 18 velocity value it has calculated based on the thickness value that was entered in step 7. 9) Press the CAL key once more to exit the calibration mode. The MMX-6 DL is now ready to perform measurements.[...]

MMX-6 DL Ultrasonic Thickness Gauge 19 Calibration to a known velocity Note: This procedure requires that the operator know the sound- velocity of the material to be measured. A table of common materials and their sound-velocities can be found in Appendix C . 1) Make sure the MMX-6 DL is on and switched to P-E (pulse-echo) mode. Press the Dual-Mult[...]

Dakota Ultrasonics 20 varies from lot to lot and from manuf acturer to manufacturer. Calibration to a sample of known thickn ess will ensure that the tool is set as closely as possible to the sound velocity of the material to be measured.[...]

MMX-6 DL Ultrasonic Thickness Gauge 21 Two Point Calibration Note: This procedure requires t hat the operator has two known thickness points on the test piec e that are representative of the range to be measured. 1) Make sure the MMX-6 DL is on and switched to P-E (pulse-echo) mode. Press the Dual-Multi key to toggle modes. Note: The calibration fu[...]

Dakota Ultrasonics 22 8) Press the Probe key. The display will flash 1OF2 . Repeat steps 3 through 7 on the second calibration point. The MMX-6 DL will n ow display the sound velocity value it has calculated based on the thickness values that were entered in step 7. The MMX-6 DL is now ready to perform measurements within this range. MMX-6 DL Modes[...]

MMX-6 DL Ultrasonic Thickness Gauge 23 The Back light The back light of the MMX-6 DL can be set to three different positions on/off/auto. The followi ng steps outline the proc edure for changing the settings of the back light: Using The Back Light 1) Press ON/OFF key to power up the MMX-6 DL . 2) Press the MODE key to activate features and settings[...]

Dakota Ultrasonics 24 measurements every second. While the transducer is in contact with the material being measured, the MMX - 6 D L is keeping track of the lowest measurement it finds. The transducer may be "scrubbed" across a surface, and any brief interruptions in the signal will be ignored. When the transducer loses contact with the [...]

MMX-6 DL Ultrasonic Thickness Gauge 25 Using the Beeper 1) Press ON/OFF key to power up the unit. 2) Press MODE key to activate features and settings. 3) Press the UP or DOWN arrow keys to scroll to bEEP . 4) Press the SEND key to toggle the stat us of the beeper on/off. 5) Press the MODE key once again to re turn to measurement mode. Alarm Mode 1)[...]

Dakota Ultrasonics 26 Dual-Multi Mode Often times users and inspectors in the field are faced with coated materials such as pipes and tanks. Typically inspectors will need to remove the paint or coating prior to measuring, or allow for some fixed amount of error introduced by the paint or coating thickness and velocity. An A-Scan scope with a speci[...]

MMX-6 DL Ultrasonic Thickness Gauge 27 RS232 Serial Port & The Data Logger The MMX-6 DL is equipped with an RS232 serial port. Using the accessory cable (part# N-306-0010), the MMX-6 DL has the ability to connect to a computer, or external st orage device. The following section outlines the procedure f or connecting the MMX-6 DL to a computer, [...]

Dakota Ultrasonics 28 Note: Communications software packages generally have the ability to capture the screen data to a comm on text file. This text file, containing the measurements, c an then be imported into any common spreadsheet prog ram (i.e. Excel  , Quattro Pro  , Lotus123  ) for further reporting requirements. Using The Data Logge[...]

MMX-6 DL Ultrasonic Thickness Gauge 29 Using the Data Logger (con't) • The current file will be dipl ayed ( F-01, F-03, etc. ) 4) Press the UP / DOWN arrow keys to scroll to the file ( 1-10 ) that will be used to record the measurements. 5) Press the SEND key once again to select the file. Note: • The display will flash the FILE / F-04 ( T[...]

Dakota Ultrasonics 30 Clearing a Storage Location The user may require a storage locati on, that is currently full, be over written. This procedure is ou tlined in the following steps: Note:  Assuming the steps in Using The Data Logger have been completed , and step 8 is being repeated. 1) Press the UP / DOWN arrow keys to move to the location t[...]

MMX-6 DL Ultrasonic Thickness Gauge 31 Clearing an Entire File The user may require the contents of an entire file be completely cleared of all measurements. This would allow the user to start a new list of measurements starting at storage location L001. The procedure is outlined in the following steps: 1) Press the ON/OFF key to power up the MMX- [...]

Dakota Ultrasonics 32 Clearing all Files 1) Press the ON/OFF key to power up the MMX- 6 DL . 2) Immediately press the CLR key. CLr? Will be displayed. 3) Press the CLR key once again to clear all files. Sending All Files to a Computer At the end of the inspection process, or end of the day, the user may require the readings be transferred to a comp[...]

MMX-6 DL Ultrasonic Thickness Gauge 33 Printing a File The user may wish to print an indi vidual file to a serial pri nter or computer. A file can, very simply, be printed to a communications program on a PC ( i.e. Windows 3. 1 - Terminal, Window 95/98/Me/XP - HyperTerminal ), and then printed. The procedure for printing a file is outlined below: 1[...]

Dakota Ultrasonics 34 TRANSDUCER SELECTION The MMX-6 DL is inherently capable of performing measurements on a wide range of materials, from variou s metals to glass and plastics. Different types of material, however, will require the use of different transducers. Choosing the correct transd ucer for a job is critical to being able to easily perform[...]

MMX-6 DL Ultrasonic Thickness Gauge 35 reduce the strength of the waves, and thus, the MMX-6 DL 's ability to detect the returning echo. Higher frequency ultrasound is absorbed and scattered more than ultrasound of a lower frequency. Whil e it may seem that using a lower frequency transducer might be better in every instance, low frequencies a[...]

Dakota Ultrasonics 36 Selection of the proper transducer is often a matter of tradeoffs between various characteristics. It may be necess ary to experiment with a variety of transducers in order to find one that works well for a given job. Dakota Ultrasonics can provide assistance in choosing a transduc er, and offers a broad selection of transduc [...]

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Dakota Ultrasonics 38 APPENDIX A Product Specifications Physical Weight: 10 ounces Size: 2.5W x 4.75H x 1.25D inches (63.5W x 120.6H x 31.75D mm). Operating Temperat ure: -20 to 120 ° F (-20 to 50 ° C) Case: Extruded aluminum body / nickel plated aluminum end caps. Keypad Sealed membrane, resistant to water and petroleum products. Power Source Tw[...]

MMX-6 DL Ultrasonic Thickness Gauge 39 APPENDIX B Application Notes • Measuring pipe and tubing When measuring a piece of pipe to determine the thickness of the pipe wall, orientation of the tran sducers is important. If the diameter of the pipe is larger than approximatel y 4 inches, measurement s should be made with the transducer oriented so t[...]

Dakota Ultrasonics 40 above this point, the change in sound velocity of the material being measured starts to have a noticeable effect upon ultrasonic measurement. At such elevated temperatures, it is recommended that the user perform a calibration procedure (refer to pag e 15) on a sample piece of known thickness, which is at or near the temperatu[...]

MMX-6 DL Ultrasonic Thickness Gauge 41 An additional important considerati on when measuring laminates, is that any included air gaps or pockets w ill cause an early reflection of the ultrasound beam. This effect will be noticed as a sudden decrease in thickness in an otherwise regular surf ace. While this may impede accurate measurement of total m[...]

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MMX-6 DL Ultrasonic Thickness Gauge 43 APPENDIX C Sound Velocities of some Common Materials M at er i al sound v el oc i t y in /u s m /s A l um i num 0. 250 6350 B i sm ut h 0. 086 2184 B r ass 0. 173 4394 C adm i um 0. 109 2769 C ast I r on 0. 180 ( appr x) 4572 C onst ant an 0. 206 5232 C opper 0. 184 4674 E pox y r esi n 0. 100 ( appr x) 2540 G[...]

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MMX-6 DL Ultrasonic Thickness Gauge 45 WARRANTY INFORMATION • Warranty Statement • Dakota Ultrasonics warrants the MMX-6 DL against defects in materials and workmanship for a period of five years fr om receipt by the end user. Additionally, Dakota Ultrasonics warrants transducers and accessories against such defects for a period of 90 days from[...]