GEInspection TechnologiesUltrasonicsKrautkramer DM4 SeriesOperating

DM4E, DM4, DM4 DLTechnical Reference and Operating ManualIdent-Nr. 28 593084-028-593

You will find a function overview of the DM4E, DM4 and DM4 DL as well as an illustration of the instrument displayincluding all display symbols and their meaning.This will help you to find information a great deal faster when reading the operating manual.This issue 05, 01/01 applies to the following software version:V 4.16All rights reserved for technical changes.

InhaltsverzeichnisTHK measurement modeor THK SPEC:DUAL MULTI PEC menu:SensitivityDisplaybacklightLanguageDM4EDM4DM4 DLTHK-measurement mode2-point calibrationVelocityMIN-measurement modeDisplay backlightlower alarm limitBaud rateDUAL MULTI measurement modeSPEC-Menü:Sensitivitylower alarm limitupper alarm limitDIF-measurement modeBandpass filterSPEC menu:LanguageBaud rateStatisticsFile headerPrinter driver0-2upper alarm limitStatisticsDIF measurementmodeFile headerBandpass filterPrinterdriverAusgabe 01, 01/99Function overviewKrautkrämer USM 25

0-2Ausgabe 01, 01/99Krautkrämer USM 25Function overviewTHK measurement modeorTHK SPEC: DUAL MULTI mode2-pointcallibrationVelocityMinimummeasurement modeSPEC menu:SensitivityDisplay backlightBattery voltageStatus symbols: over/under-limit conditions anddifferential valuesautomaticprobe recognition(Dialog probes)Calibration/SettingvaluesProbe contactMeasurementunitsDisplay overview

Content1 Introduction . 1 -12 Scope of supply and accessories. 2 -11.1 DM4E, DM4 and DM4 DL . 1 -22.1 Scope of delivery . 2 -31.2 Information about this manual . 1 -52.2 Required accessories . 2 -41.3 Layout and presentationof this manual . 1 -62.3 Recommended accessories . 2 -41.4 Important remarksabout thickness testing . 1 -7Conditions for application ofultrasonic thickness gauges . 1 -7Operator training . 1 -8Limits of ultrasonic testing . 1 -8Ultrasonic thickness measurement . 1 -9Influence of the test material . 1 -91.5 Important notes onthickness testing with the DM4 . 1 -11Probe Zero Adjustment. 1 -11Couplant rests . 1 -12Measurement precision . 1 -12Probes . 1 -12DM4 DL Data Logger . 1 -13Krautkramer DM4E / DM4 / DM4 DL2.4 Recommended outside products . 2 -63 Preparation for operation . 3 -13.1 Battery supply . 3 -2Inserting batteries . 3 -23.2 Connecting the probe . 3 -44 Basics of operation . 4 -14.1 Display . 4 -2Display indications . 4 -24.2 Keys . 4 -44.3 Switching the instrument on and off . 4 -5Indications after switching on . 4 -5Dialog probes . 4 -5Issue 05, 01/010-3

ContentNon-dialog probes: DA3 modeor AUTO mode . 4 -6Switching the instrument off . 4 -74.4 Automatic instrument switch-off . 4 -74.5 Operation concept . 4 -8Selecting operation modes/functions . 4 -8Changing settings/values . 4 -85.2 Calibrating the instrument . 5 -4Calibration with a known sound velocity . 5 -51-point calibration . 5 -62-point calibration . 5 -75.3 Thickness measurement. 5 -10Standard measurement: THK mode . 5 -10Minimum capture measurement:MIN mode . 5 -114.6 Automatic probe zero adjustment . 4 -94.7 Automatic probe recognition . 4 -104.8 Handling the probe . 4 -105 Operation . 5 -15.1 Basic settings . 5 -2Setting the display backlight . 5 -2Setting the units of measureand resolution . 5 -2Setting the unit for sound velocity . 5 -30-45.4 Additional functionsin the DM4 and DM4 DL . 5 -13Setting the sensitivity GAIN . 5 -13Setting the alarm limits . 5 -14Switching the alarm off again . 5 -15Difference mode: DIF . 5 -15Setting the bandpass filter:FLTR . 5 -16Measuring through coatings:operating mode DUAL MULTI . 5 -175.5 Activating and deactivating functions 5 -19Issue 05, 01/01Krautkramer DM4E / DM4 / DM4 DL

Content6 Operation of the Data Logger(DM4 DL only) . 6 -17 Documenting measurement values(DM4 DL only) . 7 -16.1 Data Logger . 6 -27.1 Printing data . 7 -2Preparing the printer . 7 -2Selecting the baud rate . 7 -3Selecting the report language . 7 -3Selecting the printer driver . 7 -4Selection of file header printout . 7 -5Selection of statistics printout . 7 -5Printing the measurement report . 7 -66.2 Setting the number of files . 6 -36.3 Storing the measurement values . 6 -5File selection . 6 -5Storing measurement valuesin the selected file . 6 -6Inhibiting a memory location . 6 -8Selecting a memory location . 6 -86.4 Viewing stored measurement values . 6 -96.5 Deleting stored measurement values . 6 -11Deleting and replacingindividual measurement values . 6 -11Deleting a file . 6 -11Clearing the complete memory. 6 -127.2 Transferring data to a PC . 7 -8Connnecting a PC . 7 -8Transferring data . 7 -88 Care and maintenance . 8 -18.1 Care . 8 -2Care of the instrument . 8 -2Handling AlMn batteries . 8 -28.2 Maintenance . 8 -3Krautkramer DM4E / DM4 / DM4 DLIssue 05, 01/010-5

Content9 Specifications . 9 -112 Changes . 12 -110 Interfaces and peripherals . 10 -113 Index . 13 -110.1 Interface RS 232 . 10 -2Data format . 10 -210.2 Pin layout of the 7 pinLemo socket (RS 232) . 10 -311 Appendix . 11 -111.1 Application information . 11 -2General information . 11 -2Foreign inclusions inside the material . 11 -2Surface quality . 11 -2Curved surfaces . 11 -3Thickness measurementon hot test objects . 11 -311.2 Sound velocity table . 11 -511.3 Configuration of the Data Logger . 11 -711.4 EU declaration of conformity . 11 -911.5 Service addresses . 11 -100-6Issue 05, 01/01Krautkramer DM4E / DM4 / DM4 DL

IntroductionKrautkramer DM4E / DM4 / DM4 DLIssue 05, 01/0111-1

Introduction1.1DM4E, DM4 and DM4 DLDM4E, DM4 and DM4 DLInstruments belonging to the DM 4 family are thickness gauges which are light, compact and easy touse. They are suitable for measuring wall thicknessesand remaining wall thicknesses, especially on partswhich are susceptible to corrosion and erosion (tubes,pressure vessels etc.). The great advantage with thisthickness gauge is that the test object need only beaccessible from one side.There are three versions of the DM4: DM4E DM4 DM4 DLMODEThe DM4E and DM4 have different keypads and functions; as opposed to the DM4E the DM4 has extendedfunctions. The DM4 DL is additionally equipped with adata logger which enables storage and transfer ofmeasurement data.CALONDM4EDM4E(with 4 keys)1-2Issue 05, 01/01Krautkramer DM4E / DM4 / DM4 DL

IntroductionDM4E, DM4 and DM4 DLDM4(with 5 keys)Krautkramer DM4E / DM4 / DM4 DLIssue 05, 01/01DM4 DL(with 9 keys)1-3

IntroductionDM4E, DM4 and DM4 DLExtended functions for DM4 and DM4 DL:Special features of all three versions(DM4E, DM4, DM4 DL): Automatic probe recognition; with DIALOG probesoptimum setting and performance of the instrument;especially for a higher measurement accuracy byindividually stored correction data in the probe Operating mode DUAL MULTI - measurementthrough coatings Manual gain adjustment Automatic probe zero for quick calibration Programmable minimum and maximum limits withLED alarm Automatic V-path correction for measurementlinearity over the complete measurement range Difference mode for comparing the measuredthickness with a variable nominal value Digital resolution of 0.01 mm (for thicknesses up to99.99 mm) and 0.1 mm (for thicknesses 99.99 mm)Special features of the DM4 DL (Data Logger): MIN mode with increased pulse repetition frequencyfor detection of the smallest measurement value Up to 200 hours operation with AlMn batteries Integrated Data Logger with a capacity for 5390values which can be divided into 999 files Automatic gain adjustment Access to the individual measurement values andfiles (viewing, editing and deleting), Large, easy to read digital display with switchablebacklight RS 232 interface for data transfer to a printer or PC(with special software) Lightweight, ergonomic and rugged housing1-4Issue 05, 01/01Krautkramer DM4E / DM4 / DM4 DL

IntroductionInformation about this manual1.2Information about this manualIn the following you will find information about how touse this manual. Please read these instructions carefully in order to operate all DM4 functions quickly andreliably.This will enable you to take full advantage of the instruments function range. At the same time, you willalso avoid malfunction and operating errors which, inturn, would cause incorrect test results. In the longrun, these errors could lead to injuries to persons ormaterial damage.Instrument operation is easy and quick to learn. Inorder to use the instrument as quickly as possible, youshould become acquainted with the preparation aswell as with the basic functions. Therefore, carefullyread the following chapters:Chapter 3 Preparations for operationHere you will find all the preparatory steps necessaryfor the application of the instrument.Important informationEven if you have experience in ultrasonic testing it isimperative that you observe the information containedin Chapter 1.4. Here you will find important limitationsand general conditions for thickness testing (training,knowledge of the special testing requirements, selection of the most suitable test setup). In addition to thisyou will find information about ultrasonic testing withthe DM4 in Chapter 1.5 which must be observed sothat correct readings can be guaranteed.Krautkramer DM4E / DM4 / DM4 DLPlease always look up in Chapter 12 to see if thereare any current changes. This chapter describes corrections which have been added at short notice andwhich are not yet included in the general manual. Ifthere are no additional corrections, the chapter remains empty.Chapter 4 Basics of operationThis gives you an overlook into the operation conceptof the instrument as well as about the basic operation.Chapter 5 OperationThis shows you the adjustments you can carry out andthe operation steps necessary for the measurement. Italso shows further possibilities and functions offeredby the DM4 instruments.Issue 05, 01/011-5

IntroductionLayout and presentation of this manual1.3Chapter 6 Operation of the Data Logger(DM4 DL only)The DM4 DL has the same functions as the DM4.However, it has a Data Logger (data storage) in addition to offering extra functions. Here you will learn howto store as well as to view, change and delete storeddata.Layout and presentation of thismanualIn order to make things easier for you to use thismanual, the operation steps, notes etc. are always putin the same form. In this way you will be able to quicklyfind individual information.Chapter 7 Documentation of measurement readings(DM4 DL only)Operation stepsYou can document the measurement readings via aprinter or, using a normal terminal program, transferthem to a PC and evaluate them. There are variouspossibilities available for your report.Additional information about the DM4 DL interface canbe obtained in Chapter 10. The appendix (Chapter 11)contains application information as well as sound velocity tables for materials and the distribution of files inthe Data Logger.The operation sequences are always explained insteps so that you will be able to immediately work withthe function you require.The operation steps are presented as shown in thefollowing example:– Select the function DIF with m.– .– .1-6Issue 05, 01/01Krautkramer DM4E / DM4 / DM4 DL

IntroductionImportant remarks about thickness testing1.4Note and Attention symbolsA Attention:The Attention symbol indicates peculiarities and special aspects in the operation which could affect theaccuracy of the results.H Note:Note contains e.g. references to other chapters orspecial recommendations for a function.Important remarks aboutthickness testingA Attention:Please read the following information before you useyour thickness gauge. It is very important that youunderstand and observe this information in order thatyou do not make any errors during thickness measurement which could lead to wrong measurementreadings. Decisions based on wrong measurementreadings can cause injury to people and damage toproperty.Conditions for application of ultrasonicthickness gaugesThis operating manual provides you with essentialinformation for operation of the Thickness Gauge. Inaddition to this there are a series of factors which effect the measurement readings. Description of thesefactors would go beyond the bounds of an operatingmanual. Therefore only the three most important con-Krautkramer DM4E / DM4 / DM4 DLIssue 05, 01/011-7

IntroductionImportant remarks about thickness testingditions are listed for a reliable thickness measurement: Operator training Knowledge of the special technical requirementsand limits of testing Selection of the most suitable test setupOperator trainingFor operation of an ultrasonic measurement instrument adequate training is required in the field of ultrasonic thickness measurement. Appropriate trainingincludes, for example, knowledge of the following:Insufficient knowledge of the above mentioned fieldscan cause incorrect test results and could thus haveunforseeable consequences. Information about existing possibilities with regard to ultrasonic operator training as well as qualifications and certificates can beobtained from the national NDT organizations, e.g. inGermany: the Deutschen Gesellschaft für Zerstörungsfreie Prüfung e.V., Motardstrasse 54, D-13629Berlin; or from Krautkrämer GmbH & Co., TrainingDepartment.Krautkrämer holds courses at regular intervals fortraining specialists in the field of ultrasonic testing.Dates will be given on request. Theory of sound propagation in materialsLimits of ultrasonic testing The effects of material sound velocityThe ultrasonic test information only concerns the areaof the test object which is covered by the sound beamof the probe being used. Therefore care should be takenin case conclusions from the results of the tested areaare drawn from the untested areas of the test object.Such conclusions are normally only allowed whenextensive experience exists with regard to the testobject and proven methods of statistical data acquisition are available. Behavior of sound waves at interfaces betweendifferent materials Propagation of the sound beam in the material Effect of the materials surface quality.1-8Issue 05, 01/01Krautkramer DM4E / DM4 / DM4 DL

IntroductionImportant remarks about thickness testingInterfaces within the test object can completely reflectthe sound beam so that deeper reflection positions,e.g. backwall of the test object, can no longer bereached by the sound beam. Therefore it must be ensured that the area to be tested is able to be coveredby the sound beam.Ultrasonic thickness measurementEach thickness measurement with ultrasonics isbased on a time of flight measurement of the soundpulse in the test object. The condition for exact measurement results is therefore a constant sound velocity in the test object. Normally this condition is fulfilledwith steel objects, even with different alloy contents.The sound velocity changes so little that it is only noticeable with precision measurements. In other materials, e.g. nonferrous heavy metal or plastics, the soundvelocity is subject to greater changes. Due to this, themeasurement accuracy can be effected.Krautkramer DM4E / DM4 / DM4 DLInfluence of the test materialIf the material is not homogeneous different soundvelocities can exist in various areas of the test object.Therefore an average sound velocity is to be takeninto account when calibrating the instrument.The best results are however achieved when the instrument is calibrated on a reference block made ofthe same material as the test object. This calibrationblock should have plane-parallel surfaces and have athickness which corresponds to the thickness of thetest object. In addition to this, the operator should understand that changes to the sound velocity occurwhen material is heat treated. This must be taken intoaccount with the evaluation of the thickness accuracymeasured by the instrument.If substantial sound velocity changes are to be reckoned with then the instrument calibration should bemade at shorter intervals to the existing sound velocity. If this is not made, wrong thickness readings willoccur.Issue 05, 01/011-9

IntroductionImportant remarks about thickness testingEffects of temperature changesProbe selectionThe sound velocity in the test object changes with thetemperature of the material. Therefore, under certainconditions, larger measurement errors will be produced if instrument calibration is made on a cold reference block and then the thickness measurement carried out on a warm test object. Such measurementerrors can be avoided when calibration is made with atempered reference block or when the temperatureeffect on the sound velocity is taken into account usinga correction table.The probe used for the measurement must be in agood condition, i.e. it should not have any appreciablecoupling or delay line surface wear. The measurementrange (application range) stated in the probe datasheets must cover the total thickness range to betested. The temperature of the test object must bewithin the permitted limits for the selected probe.