Extenso Meter

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8/9/2019 Extenso Meter http://slidepdf.com/reader/full/extenso-meter 1/22 243 walter+bai Testing Machines Accessories for Materials Testing EXTENSOMETERS A B C D E F G H I J K L M N O P Q R S T Extensometers for Materials Testing

Transcript of Extenso Meter

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walter+bai  Testing Machines

Accessories for Materials Testing EXTENSOMETERS

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Extensometers

for Materials Testing

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walter+bai  Testing Machines

Accessories for Materials TestingEXTENSOMETERS

By using an extensometer for direct extension measurement all additional deformation as loadframe, load cell, grips or fixtures or strain in the non-parallel section of the specimen is ex-cluded. The w+b testing machines can be equipped with direct contact or non-contacting ex-

tensometers. To challenge the wide range of applications w+b offers a comprehensive line ofextensometers:

• Axial Extensometerssuch as clip-on, averaging, semi or fully automatic extensometers.

• High Elongation Axial Extensometersfor measuring the strain of high elongation materials such as rubber, polyurethane a.s.o.

• Diametral Extensometersfor measurement of the reduction in width, Poisson’s ratio, r-value (vertical anisotropy).

• Dynamic Extensometersfor measurement of cyclical and high frequency tests.

• Fracture Mechanics Displacement Gaugesfor determination of fracture toughness properties according to ASTM E1820 and for JICKIC and R-Curves according ASTM E813.

• Video Extensometersfor simultaneous measurement of both, axial and lateral deformation, ideal for plastics,rubber, textiles, wires and many more materials.

• High Temperatures Extensometers

for the measurement inside high temperature furnaces, environmental and vacuumchambers or in connection with induction heating systems.

• Axial / Torsional Extensometerfor simultaneous measuring of axial and torsional deflections on specimens tested inaxial / torsional machines.

An accurate determination and evaluation ofthe specimen deformation is a fundamental re-quirement in many material tests.

Extensometersfor Materials Testing

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Axial Extensometers Page

 Clip-On Type DD1 - 25 / 100 246Clip-On Type MINI MFA 2 246Clip-On Type MFA 2 / 0.5 247Clip-On Type MFA 20 247Clip-On Type MFA 25 / 12 248Clip-On Series EXA 248Clip-On Series 3542 249Clip-On Miniature Series 3442 249Clip-On Long Gauge Length Series MFI 250Clip-On Long Gauge Length Series 3543 250Clip-On Long Long Travel Series 3800 251Automatic Long Travel Series MFE 252Manual / Automatic Long Travel Series MFN 252Fully Automatic Series MFL 253Fully Automatic Series MFX 253 

Axial High Temperature Extensometer Page HT Axial up to 1200°C Series EXH 254HT Axial up to 1700°C Series MFHT 254HT Axial up to 1200°C / 1600°C Series 3548 255HT Axial up to 1000°C / 1200°C Series EXAE 255

HT Self-Supporting up to 1200°C Series 3448 256HT Un-Cooled up to 540°C Series 3555 256HT Capacitive up to 1200°C / 1600°C Series 3648 257HT Axial up to 1200°C / 1500°C Series HTV 257 

Transversal and Diametral Extensometers Page Clip-On Transversal Series MFQ - H / - R 258Clip-On Transversal Series 3575 258Clip-On Transversal Miniature Series 3475 259Clip-On Transversal Averaging Series 3575 AVG 259

Automatic Transversal Series MFQ - A 260HT Diametral up to 1000°C Series 3580 260 

Digital Video Extensometer Series VEX 261

Axial / Torsional Extensometer Series 3550 261

Fracture Mechanics Displacement Gauges Page Clip-On Gauges Series EXR 262

Clip-On Gauges Series 3541 262HT Gauges up to 1200°C / 1600°C Series 3548 COD 263HT Un-Cooled Gauges up to 540°C Series 3641 263Potential Drop Crack Growth Monitor Series DMC 264

Content - Section Q

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walter+bai  Testing Machines

Accessories for Materials TestingEXTENSOMETERS

This extensometer is temperature compensat-ed in the range of -10°C up to +60 °C. Stopsat both sides protect the measuring assemblyagainst mechanical overload if the forces arenot greater than 3 N. The displacement to bemeasured is converted into a proportional elec-trical signal, where the linearity error being lessthan 0.05% over the whole measuring range.The DD1-25/100 with its quick attachment fix-

tures for both flat and round samples can easilybe mounted on the samples with the possibilityto adjust the clamping force with a high degreeof sensitivity using the mounting clamps.

Clip-On Axial ExtensometerType DD1 – 25 / 100The DD1 – 25 / 100 is specially suitable for E-Modulus, Proof- and YieldStress with flat and round specimen. One of the most precise, durableand repeatable strain measurement devices. With fast gripping system.

Features• Versatile transducer with strain gauge

measuring system• High accuracy• Compact design

Technical Data Type DD1 - 25 / 100

EN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 20 / 25 / 50 / 100 mm

Optional Gauge Length 30 / 40 to 90 / 110 to 200 mm

Measuring Range ± 2.5 mm

Linearity Error incl. Hysteresis < 0.05 %

Dimensions Flat / Round Specimens ❏4 - 50 mm / Ø 5 - 50 mm

The extensometer permits quick and easyexamination of a large number of test sam-ples. Its low weight and minimal activatingforce make it especially suitable for small andnotch sensitive samples. The measurementrange amount to 2 mm in the positive (ten-sile) and 1 mm in the negative (compression)direction. The large adjustment range of theclamping force allows for the optimal adap-tation to the tested material and the sam-ple dimensions. Mechanical stoppers pro-tect against unintended overloads, even inthe case of premature breaking of the sam-

Clip-On Axial ExtensometerType MINI MFA 2Suitable for almost all types of samples up to Ø 25 mm or ❏25 x 25 mmand a gauge length Lo of 100 mm. Very high resolution and accuracy al-low the determination of Young’s modulus and the yield point RP0.2.

ple with the extensometer attached. The MINIMFA 2 has a gauge length Lo of 10 mm. Withthe basic model an extension arm for Lo 50mm is provided. Further extension arms forLo 10 to 100 mm can be supplied giving in-termediate lengths. The clamping device if theMINI MFA 2 permits fast and unproblemat-ic clamping and unclamping. Two MINI MFA2 can be used with the double clamping de-vice in order to average the strain for sample.For the double-side MINI MFA 2 as well asfor thin round samples rectangular edges arerecommended.

Technical Data Type MINI MFA 2

EN ISO 9513 Accuracy Class 0.5Standard Initial Gauge Length 10 mm

Optional Gauge Length 50 / 100 mm

Measuring Range + 2 mm / - 1 mm

Linearity Error incl. Hysteresis 0.05%

Dimensions Flat / Round Specimens ❏0 - 25 x 25 mm / Ø 0 - 25 mm

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Its measuring accuracy exceeds all requirementset down by standard EN ISO 9513. Its design,which has been tried and tested over manyyears of use, guarantees a high level of reliabil-ity and a long service life, even under difficultconditions. The MFA is fast, straightforward andeasy to use, and therefore enables large num-bers of tests to be carried out. A lever mountedin ball bearing, which have been tensioned to

prevent play, and housed in a casing of a highstrength aluminium ally is used to take up theclamping forces. The path of the test elongation

Clip-On Axial ExtensometerType MFA 2 / 0.5Particularly suitable for determining the module of elasticity, proofstress and ultimate strain. Suitable for all tests above an initial instru-ment length Lo of 25 mm.

is transferred to the measuring spring throughthis lever. If the measuring distance (path) isexceeded of the test piece breaks prematurelywhen the MFA is in use, the measuring spring isfully protected by stops. The Lo of the measur-ing instrument can be equipped for all requiredlengths from 25 to 300 mm. The extensionarms can be changed quickly and without tools.The basic equipment comprised the exten-

sions arms for Lo 30 (25) mm and Lo 50 mm.The clamping device facilities quick and easyclamping.

Technical Data Type MFA 2 Type MFA 0.5

EN ISO 9513 Accuracy Class 0.2 0.2

Standard Initial Gauge Length 30(25) and 50 mm 30(25) and 50 mm

Optional Gauge Length 30 - 300 mm 30 - 300 mm

Measuring Range 2 (3) mm 0.5 mm

Linearity Error incl. Hysteresis 0.05 % 0.05 %

Dimensions Flat SpecimensDimensions Round Specimens

❏0 - 30 x 30 mm / 0 - 60 x 60 mm with adapter

Ø 0 - 30 mm / 0 - 60 mm with adapter

Clip-On Axial ExtensometerType MFA 20Suitable for determining the yield point and uniform deformation for sam-ples above 4 mm diameter and 15 mm width. Extremely robust design forheavy duty service such as testing of construction steel and rough samples.

The MFA 20 consists of two casing halveswhich move parallel and easily towards eachother on play-free guidance bars. The uppercasing overlaps the lower casing for the to-tal extension so that the parallel guide andthe measuring system are protected fromdamage and dust. A measuring spring witha temperature compensated full bridge straingauge serves as the measuring system forthe MFA 20. The knife edge holders and theclamping device can be positioned easily byloosening just one knurled screw. Alignment

pins fix them in their exact position. In orderto achieve a symmetrical position of the coun-ter rollers with respect to the knife edges, thecounter roller fixture can be turned and theclamping device shifted in three steps. Open-ing width and clamping force are continuallyadjustable.

Features• parallel-guided• roller-bearing design, extremely robust

design

Technical Data Type MFA 20

EN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 50 - 100 mm (Steps of 10 (5) mm)Optional Gauge Length from 40 mm / up to 200 mm

Measuring Range + 20 mm

Linearity Error incl. Hysteresis 0.2%

Dimensions Flat Specimens ❏15 x 1 up to 30 x 30 mm (Option 60 x 60 mm)

Dimensions Round Specimens  Ø 4 - 30 mm (Option 60 mm)

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Accessories for Materials TestingEXTENSOMETERS

Dynamic Clip-On Axial ExtensometerSeries EXASpecially designed for testing new materials, such as carbon fibres, ce-ramics a.s.o. as well as organic materials. It is characterised by very lowweight, high natural frequency, and a high accuracy of ± 0.1 % of full scale.

It allows also dynamic endurance strength

tests on very small specimens to be per-formed without giving problems. Attachmentsprings supplied will ensure quick and safeattachment to the specimen. The standard60’ knife edges can be replaced when wornin a matter of minutes. Upon special request,knife edges are available with different an-gles and supports and/or in other materials.

Application Range

• Tension / Compression Tests - Young-Modulus and Elastic Limit• Low and High Cycle Fatigue Tests• Deformation of Bending Tests

Technical Data Series EXA

EN ISO 9513 Accuracy Class 0.5 - 1

Standard Initial Gauge Length 10 - 100 mm (in steps of 5 / 10 mm)

Measuring Range 0.25 - 10 mm

Linearity Error incl. Hysteresis 0.1 - 0.3 %

Operating Temperature - 80°C - +120°C or -270°C - +220°C

Dimensions Flat Specimens ❏1 - 18 mm

Dimensions Round Specimens Ø 1 - 18 mm

The measuring arms are made of a highstrength aluminium alloy. Along with ballbearings which have been tensioned to pre-vent play the measuring arms are placed onthe rotation point. This results in a simplebut stable design which being easy to op-erate is suitable for a rational testing of alarge number of test pieces. The measuringspring attached to the upper arm transfers

the movements of the measuring directiononly onto a fine, lapped surface of the lowerarm. This prevents any form of distortion from

Clip-On Axial ExtensometerType MFA 25 / 12Suitable for many specimens above an initial gauge length of Lo 25 mm.At a measuring path of 25 mm specially designed for metal and plastic.Specially the low tension causes only a little force on the specimen.

either the clamping force or any other kindof force. As each measuring arm has its owncounter roller the relative distance travelledby the backing rollers corresponds to themeasuring path. Due to this, only very slightcounter forces effect the test pieces. The non-linearity (< 0,5 % V.A) of the MFA 25 comesfrom its axis-suspension and its long meas-uring path of 25 mm. A special model of the

MFA can be supplied for tests in the tempera-ture range of +1°C to +220 °C.

Technical Data Type MFA 25 Type MFA 12

EN ISO 9513 Accuracy Class 0.5 0.2

Standard Initial Gauge Length 25 and 50 mm (20 mm) 25 and 50 mm (20 mm)

Optional Gauge Length 30, 80 and 100 mm 30, 80 and 100 mm

Measuring Range + 25 mm + 12 mm

Linearity Error incl. Hysteresis 0.25 % 0.10 %

Dimensions Flat Specimens ❏0 - 28 x 30 mm / 0 - 50 x 50 mm with adapter

Dimensions Round Specimens Ø 0 - 28 mm / 0 - 50 mm with adapter

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Accessories for Materials Testing EXTENSOMETERS

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These extensometers are designed for testing awide range of materials, including metals, plas-tics, composites and ceramics. All will work inboth tension and compression. The dual flex-ure design makes them very rugged and insen-sitive to vibrations, which permits higher fre-quency operation. They have quick attach kitto make it easy to mount the extensometer onthe test specimen in seconds with one hand.

The quick attach kit can be removed, allowingmounting of the extensometer with springs orrubber bands. Operating Force <30g.

Clip-On Axial ExtensometerSeries 3542For Axial Tensile, Compression and Cyclic Testing of a wide range of ma-terials, including metals, plastics, composites and ceramics. Optional withrubber or spring band attachment.

Features• May be left on through specimen failure.• All models can measure in both tension

and compression and can be used for cy-clic testing.

• Rugged, dual flexure design for strengthand improved performance. Muchstronger than single flexure designs,this also allows cyclic testing at higher

frequencies.• Options: adapter kits to change gauge

length and speciality knife edges.

Technical Data Series 3542

EN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 10, 12.5, 25, 50 mm

Measuring Range ±5, ± 10, ± 20, ± 25%, +50 / - 10%, +100 / - 5 %

Linearity Error incl. Hysteresis 0.10 % (for ± 5 and 10%), 0.15 % (rest)

Operating Temperature -265°C up to +175°C

Dimensions Flat Specimens ❏0 - 12 x 31 mm

Dimensions Round Specimens Ø 0 - 25 mm

Weighing as little as 8 grams, these tiny ex-

tensometers also have very low operat-ing force, resulting in low specimen contactforce and influence. All use a proprietary dualflexure design, which makes them very rug-ged for their size. Most are only 15.25 mmtall. These extensometers will fit in the smallspace between grips, which usually resultswhen small test samples are used. The 3442are strain gauged devices, making them com-patible with any electronics. Optional withsring or rubber band attachment.

Axial Miniature ExtensometerSeries 3442These units are widely used for testing small and delicate samples. Ide-al for biomedical tests, as well as for wire and thin sheet materials. Alsogreat for low cycle fatigue testing where short samples are used.

Features

• Mechanical over travel stops in bothdirections.• Hardened tool steel knife edges are easily

replaced. Optional special coatings andstainless steel knife edges available forbiomedical tests.

• Rugged, dual flexure design for strengthand improved performance. Much strong-er than single flexure designs, this also al-lows cyclic testing at higher frequencies.

Technical Data Series 3442

EN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 3, 4, 5, 6, 8, 10, 12 mmMeasuring Range ±5, ±10, +20 / - 10%, +50 / - 5%, +100 / - 5 %

Linearity Error incl. Hysteresis 0.10 % (for ± 5 and ± 10%), 0.15 % (rest)

Operating Temperature -265°C up to +175°C

Dimensions Flat Specimens ❏0 - 12 x 25 mm

Dimensions Round Specimens Ø 0 - 12 mm

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Accessories for Materials TestingEXTENSOMETERS

It can be operated in horizontal and verticaltesting machines. In spite of its sturdy con-struction and the large Lo variation, it is easyto operated due to its low weight. The MFIcomes in a tubular design that extends like atelescope. The measuring system, a well pro-tected inductive transducer, is mounted at itscentre. The clamping elements are arrangedat the ends of the instrument, so that Lo can

be utilised to almost the grips of the testingmachine. On the clamping elements five knifeedges are arranged in a circular arc, which at-tach firmly to round, twisted or plaited sam-

Axial Long Gauge Length ExtensometerSeries MFIParallel guided design measuring the deformations of samples with alarge gauge length Lo up to 1000 mm. Specially suitable for wire cables,chains, construction concrete and steel rods, belts, ropes a.s.o.

ples form 3 to 35 mm diameter. The edgesare circular and can be rotated. A long life isachieved by using the whole perimeter. Forfind adjustment of clamping a spindle with aspring loaded pressure plat is arranged facingthe knife edges. A combination of different ex-tension tubes allow the extension of the basicLo to any length up to 1 m. For a tensile test noadjustment or unbolting on the MFI is needed.

By setting the MFI to the gauge length , theclamping elements centre themselves in sucha way during clamping the instrument alignsitself parallel to the samples axis.

Technical Data MFI 20 MFI 40 MFI 100

EN ISO 9513 Accuracy Class 1 1 1

Standard Initial Gauge Length 225 mm 250 mm 300 mm

Optional Gauge Length 226 - 1000 mm 251 - 1000 mm 301 - 1000 mm

Measuring Range + 20 mm + 40 mm + 100 mm

Linearity Error incl. Hysteresis 0.2 % 0.2 % 0.2 %

Dimensions Round Specimens Ø 3 - 35 mm Ø 3 - 35 mm Ø 3 - 35 mm

The unique pull-apart design protects the ex-tensometer when the specimen fails. These aretension only units. During operation, the upperhalf of the extensometer pulls out of the mainbody. Tapered measuring beams activate straingauged flexures within the unit. This unique de-sign allows long measuring ranges, yet retainsthe compatibility with electronics for straingauged transducers. These models offer highaccuracy and are light weight but rugged, withlow operating force. The units have hardened

Axial Long Gauge Length ExtensometerSeries 3543These extensometers are specially designed for long samples are idealfor testing steel re-bar, weld joints, and wire materials. It is a uniquelydesigned unit that may be left on through specimen failure.

tool steel knife edges. Standard quick attachwires provided with the extensometer workon flat specimens up to 12 x 31 mm and onrounds up to 25 mm diameter. Optional quickattach kit wire forms are available for use onlarger samples. Specifically designed to be lefton through specimen failure. The unit is de-signed so that the two halves of the extensom-eter come apart to prevent damage at speci-men failure. The optional gauge length spacersallow the gauge length to be easily increased.

Technical Data Series 3543

EN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 50, 100, 150, 200 or 250 mm

Measuring Range +25, +50, or +100 mmLinearity Error incl. Hysteresis < 0.15%

Dimensions Flat Specimens ❏0 - 12 x 31 mm

Dimensions Round Specimens Ø 0 - 25 mm

Temperature Range ST -40°C - +100°C or HT -40°C - +1500°C

Typical Operating Force 125 g

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Axial Long Travel ExtensometerSeries 3800Designed for plastics, rubber and elastomer testing, these extensome-ters have very long measuring ranges. Their unique design allows test-ing to failure and minimizes interaction with the sample.

The main body of this unique extensometerremains stationary during testing, held in po-sition by the adjustable magnetic base includ-ed. Only the very light, small travelling headsmove as the sample elongates during a test.These attach to the sample with small springclips. Each head pulls a cord out from the ex-tensometer as the head moves. These mod-els use high precision, low friction potenti-

ometers, and, as a result, have a wide rangeof factory selectable outputs. The extensom-eter is driven by an excitation voltage and hasoutput proportional to the input. They canbe provided with high level outputs (approx-

imately 2-8 VDC) or ones that mimic straingauged devices (2-4 mV/V).

Features• May be left on through specimen fail-

ure. The main body is stationary withonly the lightweight travelling headsmoving.

• Comes with an adjustable magneticbase for easy mounting.

• Low cost, high accuracy elastomersstrain measurement.

Technical Data Series 3800

EN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 25 or 50 mm

Measuring Range +125, +250 or +500 mm

Linearity Error incl. Hysteresis < 0.15%

Typical Operating Force 20 g

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walter+bai  Testing Machines

Accessories for Materials TestingEXTENSOMETERS

Particular attention has been paid to priceand functional performance in the designand construction of the device. The MFE hasa smooth-running, near-frictionless guidancesystem (comparable to air-guidance), whichin conjunction with the newly designed meas-uring system, guarantees a robust and reli-able basis for measurement. The MFE workssemi-automatically, indicating position rel-

ative to a manually set initial gauge lengthand incorporating electric motors to open andclose the measuring arms. All of these func-tions are computer-controlled and in situa-

Automatic Long Travel ExtensometerSeries MFESpecially designed for highly lengthening materials such as plastics andrubber, incorporating long travel up to 900 mm. The MFE complementsrelatively low-cost instruments used for the testing of plastics.

tions where the initial gauge length and theposition of the sample are unchanged, nomanual adjustment is necessary. Elongationis recorded by means of an opto-incrementalmeasuring system. The MFE may be config-ured with either downward or upward meas-urement directions. The measuring arms maybe easily and quickly removed from the deviceby unlocking two screws with pin guidance.

Dual Range MFN - Aoffers both small (4 mm, achieves the highestmeasurement accuracy) and large measuring

range. MFN - A is highly suitable for determiningthe Young’s Modulus and for recording fractureelongation Lo+DL = 800 mm.

Long Path MFN - BOffers only the large measuring range. It servesin measuring large sample extensions as ob-served in elastomers.

Manual / Automatic Axial ExtensometerSeries MFNAvailable in 14 models with different measuring systems for differentelongation and in automatic or manual mode.

Short Path MFN - COffers only the small measuring range (4 mm).The guided length of 500 mm serves to move

the arms with respect to the sample centre andto adjust them for different clamping heights. Inthe manual version the measuring arms must beopened, closed and pushed to the Lo-stop byhand. In the automatic version the measuringarms are opened, closed and set at the manu-ally preset Lo and position by an electrical mo-tor. These functions may be controlled by a PC.

Technical Data MFN - A MFN - B MFN - C

Digital 4 + 300 mm 300 mm

Standard 4 + 500 mm 500 mm + 4 mm

Long 4 + 800 mm 800 mm

Technical Data Short Path Long Path Digital Long Path Analog

Measuring Ranges + 4 mm 300 mm 500 or 800 mm

EN ISO 9513 Accuracy Class 0.2 2 (0.5 for > 4 mm) 1 for > 4 mm

Standard Initial Gauge Length 50 (10 - 25 option) 10 - 100 mm 100 - 100 (250) mm

Linearity Error incl. Hysteresis 0.06 % 0.01 % 0.025%

Specimen Dimensions ❏0 - 30 x 70 mm / Ø 0 - 30 mm

Technical Data MFE 900

EN ISO 9513 Accuracy Class 2

Standard Initial Gauge Length 10 to 100 mm in steps of 10 mm

Measuring Range 910 mm minus Lo

Linearity Error incl. Hysteresis 0.20 %

Dimensions Flat Specimens ❏0 - 30 x 100 mm

Dimensions Round Specimens Ø 0 - 30 mm

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The MFL can be connected to partly or ful-ly automatic testing machines with hydrau-lic grips. The strain can be measured from theelastic range to fracture for almost all types ofsamples. When used in combination with theMFQ, the MFL is highly suitable for testing thedeep-drawing properties (vertical anisotropyr) of thin sheets. Each one of the four measur-ing arms of the MFL has a measuring spring

bonded with a full bridge strain gauge. Themeasuring springs of a right and left arm pair

Fully Automatic Axial ExtensometerSeries MFLFor use in connection with fully automatic testing machines. Low clamp-ing force combined with the high measurement accuracy makes it suita-ble even for small, notch sensitive test samples.

are connected in parallel to obtain an aver-age value, which is important if the sampledeforms non-homogeneously. DC- tacho mo-tors compensate the changes in the measur-ing spring signal initiated through the sampleelongation by a ball-bearing gear, ensuringthat the measuring heads move according tothe sample elongation and make the measur-ing heads follow the sample extension. The

elongation is recorded by an opto-incremen-tal measuring system.

Fully Automatic Axial ExtensometerSeries MFXFor use in connection with fully automatic testing machines. Because of itsrugged construction and the high accuracy the Series MFX nearly meets allapplications in measurement of linear strain.

The MFX is suitable for almost all samples ofa gauge length (Lo) from 10 mm. Becauseof its rugged construction and high accura-cy the MFX nearly meets all applications inmeasurement of linear strain (determinationof the E-modulus up to sample fracture). TheMFX works without restrictions in both theupper as well as the lower test area. Whenused in combination with the MFQ-A theMFX is highly suitable for testing the deep-drawing properties (vertical anisotropy r) ofthin sheets. The MFX has a smooth running

and nearly frictionless linear guidance of themeasuring heads. Due to the noncontact in-cremental gauge the MFX meets all require-ments of class 0.5 over the whole travel. Bymoving the upper measuring head manuallythe initial gauge length can be increased for100 mm without any restriction of the meas-uring travel. The MFX can be controlled via aPC. The built in measuring system is a non-contact type. Maximum resolution 0.1 µm.Clamping Force 50 - 100 cN. Activating Forcemax. 10 cN.

Technical Data MFX 900

EN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 10 - 200 minus travelMeasuring Range 200 minus Lo

Positioning Range 120 mm without restriction of travel

Linearity Error incl. Hysteresis 0.005 %

Dimensions Flat Specimens ❏0 - 50 x 150 mm

Dimensions Round Specimens Ø 0 - 50 mm

Technical Data MFL 300 MFL 500

EN ISO 9513 Accuracy Class 0.5 0.5

Standard Initial Gauge Length from 10 mm from 10 mm

Positioning Distance 200 mm 200 MM

Measuring Range 300 mm minus Lo 490 mm minus Lo

Linearity Error incl. Hysteresis 0.005 % 0.005 %

Dimensions Flat Specimens ❏0 - 30 x 50 mm ❏0 - 30 x 50 mm

Dimensions Round Specimens Ø 0 - 80 mm Ø 0 - 80 mm

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walter+bai  Testing Machines

Accessories for Materials TestingEXTENSOMETERS

The Extensometer is provided with a specialspring enabling it to be attached elastically tothe heat chamber or machine frame. Move-ments on the machine are thus not registeredas measurement errors at the extensometer.This spring, in conjunction with two knurlednuts, presses the transmission rods quicklyand securely to the specimen. If, when hardmaterials are tested, the ceramic rods should

slip, a special punching device, from therange of accessories, is available to preventthat this happens. This will provide on thespecimen two centring points on the speci-men to accommodate the rod tips. A heat

High Temperature Axial ExtensometerSeries EXHFor measurement in radiation or three-zone heating furnaces with up to1200 °C. Measurement data are transmitted from the specimen throughthe furnace to the extensometer via two ceramic rods fitted at both ends.

screen protects extensometers from excessiveheat. Ideal for accurate measuring strain inhigh-temperature tension, compression andthrough-zero fatigue testing applications. Foruse at temperatures up to 1’200°C and withoptional water cooling up to 1’800°C. Securestain measurement without slippage withelastically low contact force minimizes thepossibility of damage to the specimen. Acti-

vation force only 2 N.

Initial measuring lengths from 10 to 100 mmmay be set quickly and easily. Due to its ex-tremely low actuating force, the unit enablesthe testing of highly sensitive samples whichpermit only the lowest surface pressures.Built-in heating elements maintain an adjust-able constant temperature inside the measur-ing unit. The feeler arms are mounted on le-vers which are locked free from float in pivotbearings. Measuring springs which are appliedby full bridge resistance strain gauges are ac-tuated via these pivots. Coil springs press thefeeler arms which are driven by a motorizedspindle drive gently against the sample. In ad-

High Temperature Axial ExtensometerSeries MFHTConceived as a highly accurate, sturdy measuring device for hot tensiletests in a folding furnace up to 1700°C. The temperature range dependson the material of the feeler arms which are easy to exchange.

dition the drives release both L0 limit stopsprior to measuring in order to prevent the ap-plication of preload force to the feeler arms.The feeler arms can be controlled by means ofa control cassette which is part of the deviceor by a computer with relay board. The cas-sette also contains the programmable temper-ature control. A ventilator provides even tem-perature distribution within the MFHT.

Technical Data Series EXH

EN ISO 9513 Accuracy Class 1

Standard Initial Gauge Length 15, 20, 25, 30 or 50 mm (1.25 - 10 mm optional)

Measuring Range 0.75 - 10 mm

Linearity Error incl. Hysteresis 0.25 %

Operating Temperature up to 1200°C (with option up to 1800°C)

Technical Data Type MFHTEN ISO 9513 Accuracy Class 0.2

Standard Initial Gauge Length 15, 20, 25, 30 or 50 mm

Measuring Range 10 or 8 mm

Linearity Error incl. Hysteresis 0.05 %

Operating Temperature up to 1700°C

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These extensometers mount on a water-cooledbracket mounted on the furnace side cut-outor with other support brackets. The standardtemperature version (to 1200 °C) is suppliedwith high purity alumina rods. The high tem-perature option is furnished with alpha gradesilicon carbide rods. Rods are made to order tothe length required for your furnace. Mountingbrackets may be integrated with the furnace

cut-out. Optional load frame mounting brack-ets can be provided.

Features• May be left on through specimen failure.

High Temperature Axial ExtensometerSeries 3548High temperature extensometers for use in side cut-out, split type ma-terials testing furnaces. Water cooled and furnace bracket mounted foruse to 1200 °C. The high temperature option allows use up to 1600 °C.

• All models can measure in both tensionand compression and can be used forcyclic testing.

• Mechanical over travel stops in bothdirections.

• Rugged, dual flexure design for strengthand improved performance.

• Optional versions for use in vacuum en-vironment upon request!

Rod Tip Styles• Straight Chisel for flat & round specimens• Vee Chisel for round specimens only• Conical Tip for flat specimens only

High Temperature Axial ExtensometerSeries EXAESpecially designed for LCF (Tensile, Compression or Through-Zero), Creepor Relaxation Testing. Can be perfectly used in combination with dy-namic rated hydraulic or manual high temperature grips Series HTG.

The EXAE Extensometer with replaceable in-serts is available for testing different bars. Itis mechanically operated and features doubletelescoping rod and tube construction witha variable gauge length of 25 to 152.4 mm.Different specimen geometries can be ac-commodated with the appropriate replace-able knife-edges which are easy change orreplaced when they become dull. The two pre-cision displacement transducers are placedoutside of furnace with attachment to speci-men by means suspension arms. The EXAE ex-tensometers features excellent concentricitywith very low specimen bending and assure

no slippage-free testing. Zero TemperatureCoefficient ±0.01% F.S. /°C, Span Tempera-ture Coefficient ±0.01% F.S. /°C.

Features• Ideal for accurate measuring strain in

high-temperature tension, compres-

sion and through-zero LCF testing

applications.

• For use at temperatures up to 1200°C.

• Secure stain measurement without

slippage.

Technical Data Series EXAEEN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 25 - 152.4 mm

Measuring Range 5, 10, 15, 20, or 25 mm

Linearity Error incl. Hysteresis 0.10 %

Operating Temperature 1000°C, 1100°C or 1200°C

Technical Data Series 3548

EN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 10, 25 or 50 mm

Measuring Range ± 10 %, ± 20%, + 50 % / - 25 %, + 100 % / - 5 %

Linearity Error incl. Hysteresis < 0.15 mm

Operating Temperature Standard ST up to 1200°C, Option HT up to 1600°C

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These extensometers use a high tempera-ture capacitive sensor and do mot require anycooling. They will operate up to the maximumtemperature limit of most environmentalchambers used in material testing. The Series3555 is ideal for testing of composites, met-als and high temperature polymers in tensile,compression of cyclic testing. All units can bedisplayed in both compression and tension.The extensometer can also be used for straincontrolled tests like low cycle fatigue.

HT Un-Cooled Axial ExtensometerSeries 3555For use in environmental chambers where the entire extensometer mustbe exposed to elevated temperatures. These capacitive extensometersmay be used up to 540 °C without any cooling.

Features

• All models can measure in both tensionand compression and can be used forcyclic testing.

• Rugged, dual flexure design forstrength and improved performance.Much stronger than single flexure de-signs, this also allow cyclic testing athigher frequencies.

• Recommended for elevated tempera-ture testing in air or some other gases.

HT Self-Supporting Axial ExtensometerSeries 3448Designed for use with high temperature furnaces or induction heatingsystems. The units are held on the specimen by light, flexible ceramic fibercords. These make the extensometer self-supporting on the specimen.

The units are held on the specimen by light,flexible ceramic fiber cords. These make the ex-tensometer self-supporting on the specimen.No furnace mounting brackets are required.The side load on the test sample is mostlyeliminated because of the self-supporting de-sign and light weight of the sensor. The com-bination of radiant heat shields and convec-tion cooling fins allow this model to be used

up to 1200 °C without any cooling. High puri-ty alumina (min 99.7%) ceramic rods are usedwith either chisel, vee chisel or conical contactpoints as desired. Tensile, compression and cy-clic tests like low cycle fatigue can all be per-

formed with a single unit.

Features• May be left on through specimen failure.• Mechanical overtravel stops in both

directions.• Use without cooling to 1200 °C. Option-

al small fan improves stability at highesttemperatures.

• May be used on nearly any furnace withside entry cut-out for extensometers.

• Alternate configuration available forinsertion between coils of inductionheaters.

Technical Data Series 3448

EN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 10, 25 or 50 mm

Measuring Range ±5, ± 10, ± 20, +50 / - 20%

Linearity Error incl. Hysteresis < 0.15 %

Operating Temperature Ambient up to 1200°C

Technical Data Series 3555

EN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 10, 25 or 50 mmMeasuring Range ±5%, +10% / -5%, +20% / -10%, +50% / -10%

Linearity Error incl. Hysteresis 0.10 %

Operating Temperature Ambient up to 540°C

Dimensions Flat Specimens ❏0 - 12 x 19 mm

Dimensions Round Specimens Ø 0 - 12 mm

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These high-temperature extensometers fea-ture a plug-in module for stylus approachcontrol to the surface of the specimen withautomatic recognition of contact with thespecimen and with automatic stopping whenadequate contact force has been generatedat the specimen (module installed to the tem-perature controller’s electrical cabinet). Thisextensometer having a measuring travel of10 mm or 0 / +20 mm and adjustable gagelength from Lo 10 to 50 mm.Including extensometer mounting device forswivelling and movable installation of theHTV extensometer on the testing machine.

HT Axial ExtensometerSeries HTVSpecially designed for use with high temperature furnaces up to1200°C or 1500°C. Automatic recognition of contact with the specimen andautomatic stopping.

Series HTV – Awith MotorizedStylus Approach

to the surface of the specimen by electricmotor

Series HTV – Mwith ManualStylus Approach

to the surface of the specimen by hand-wheel

Technical Data Series HTVEN ISO 9513 Accuracy Class 1

Standard Initial Gauge Length 10 to 50 mm (10 to 70 mm optional)

Measuring Range ± 10 mm or 0 / + 20 mm

Linearity Error incl. Hysteresis 0.25 %

Operating Temperature up to 1200°C or up to 1500°C)

These extensometers use a high temperaturecapacitive sensor in combination with an in-novative design to achieve high accuracy strainmeasurements in low measuring ranges notpossible with other high temperature extensom-eters. These extensometers mount on a slidebracket that can attach to the load frame ofyour test system; optional load frame mountingbrackets are available. The standard tempera-

ture version is supplied with high purity aluminarods. The high temperature option is furnishedwith alpha grade silicon carbide rods. Option-al load frame mounting brackets. Rod tip stylesstandard chisel, vee-chisel or conical point.

HT Capacitive Axial ExtensometerSeries 3648Features very low specimen contact force and are available in low strainranges for use with induction heating systems. Water-cooled and mountedto a slide bracket, these are for use to 1200 °C, optional up to 1600 °C.

Features• All models can measure in both tension

and compression and can be used forcyclic testing.

• Mechanical over travel stops in bothdirections.

• Innovative slide mount allows the ex-tensometer to engage the specimenonce the test temperature has been

achieved.• Low strain range, high resolution ver-

sions available.• Typical operating force <10 g. Contact

force up to 150 g (30 - 50 g typically.)

Technical Data Series 3648

EN ISO 9513 Accuracy Class 0.5

Standard Initial Gauge Length 10 or 25 mm

Measuring Range between +0.25 and 2.5 mm upon request!

Linearity Error incl. Hysteresis 0.10 %

Operating Temperature Standard up to 1200°C. HT-Option up to 1600°C.

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Whereas the MFQ-R is infinitely variable toeach diameter of specimens the MFQ-H isequipped with fixed B0-stops for fixed initialwidth of metal sheets. The stoppers are easyand quick to change without any tools. MFQ-H and MFQ-R are both deliverable with twomeasuring locations (parallel switched for de-termination of the average value) as well aswith only one measuring location. Sensitivity

2 mV/V. Pressing force of the measuring pin4 N / 2 N.

Clip-On Transversal ExtensometerSeries MFQ - H and Series MFQ - RSeries MFQ - H: Determination of the ‘r-value’ (vertical anisotropy) on

metal sheetsSeries MFQ - R: Determination of the ‘Poisson’ value on round samples

Features• Low weight• Comfortable clamping• Easy adjustment to different diameters

of specimens• Maintenance of the position of the

measuring points also during the ten-sion test through a smooth-runningguide rail system (MFQ with two meas-

uring locations)

Self-supporting on the test sample, these ex-tensometers will work on any width or di-ameter specimen from 0 to 25 mm. They arecommonly used for measurement of Poisson’sratio, for transverse measurements with ani-sotropic materials like many composites andfor sheet metal testing such as r-value deter-mination. Most often they are used simulta-neously with axial extensometers. These unitseasily clip onto the sample, held in place withan integral spring. Rounded contact edgesmaintain the position on the specimen.

Clip-On Transversal ExtensometerSeries 3575Designed for general purpose transverse or diametral strain measure-ment on axially loaded specimens. This model may be used simultane-ously with the Model 3542 axial extensometer.

Features• May be left on through specimen failure.• All models will measure both positive

and negative displacements.• Rugged, dual flexure design for strength

and improved performance. Muchstronger than single flexure designs,this also allows cyclic testing at higherfrequencies.

• Easy to mount, with integral springs tokeep the extensometer on the sample.

• Self-supporting on the specimen.• Optional with speciality knife edges.

Technical Data Series 3575

EN ISO 9513 Accuracy Class 0.5Measuring Range ± 0.5, ± 1, ± 2.5, ± 3 or ± 5 mm

Linearity Error incl. Hysteresis < 0.15 mm

Operating Temperature - 265 °C up to +175°C

Dimensions Flat Specimens ❏0 - 25 mm

Dimensions Round Specimens Ø 0 - 25 mm

Technical Data MFQ - H MFQ - R

EN ISO 9513 Accuracy Class 0.2 0.2

Measuring Range 4 mm (6 mm optional) 4 mm (6 mm optional)

Linearity Error incl. Hysteresis 0.05 % 0.05 %

Measuring Range 300 mm minus Lo 490 mm minus Lo

Specimen Thickness Flat Samples 0.4 - 30 mm 0.4 - 30 mm

Specimen Widths Fixed Flat Samples 13, 20, 25, 30 mm 4 - 25 mm (50 mm)

Specimen Diameter Round Samples - 4 - 25 mm (4 - 50 mm)

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This extensometer is self-supporting on thesample. It has rounded contact edges whichmeasure the sample at two locations. As thetest sample is pulled, the contact edges fol-low the part of the sample they were mount-ed on, measuring lateral strain on the sam-ple at the same location throughout the test.The extensometer has a single output, whichis the average of the two lateral measure-ments. These extensometers are used with a50 mm gauge length Model 3542 extensom-eter, which measures the axial strain.

Transversal Averaging ExtensometerSeries 3575 AVGDesigned for measuring r-values in sheet metal testing, this extensom-eter averages the lateral strain at two locations. This model may be usedsimultaneously with the Model 3542 axial extensometer.

Features

• May be left on through specimenfailure.• Rugged, dual flexure design for strength

and improved performance. Muchstronger than single flexure designs.

• Self-supporting on the specimen• Measuring range of or 2 mm (specify).• Single clip-on unit directly measures

lateral strain as an average of twolocations.

• Greatly speeds up testing and allowsdigital data collection as compared tomanual measurements.

Technical Data Type 3575 AVGEN ISO 9513 Accuracy Class 0.5

Measuring Range 2 mm

Linearity Error incl. Hysteresis < 0.15 %

Operating Temperature - 265 °C up to +175°C

Dimensions Flat Specimens ❏9.5 - 25 mm

Miniature Transversal ExtensometerSeries 3475A miniature extensometer designed for general purpose transverse ordiametral strain measurements on small or thin specimens. May be usedsimultaneously with the Model 3442 or Model 3542 axial extensometers.

These very lightweight extensometers are self-supporting on the test sample. They are used formeasuring the transverse or diametral strain. Of-ten they are used simultaneously with an axi-al strain measuring extensometer to determinePoisson’s ratio. They also are used for character-izing materials with anisotropic properties, suchas with many composite materials. This modelclips easily onto the sample with an integral

spring to hold the unit in place. It can be adjust-ed to work on any size sample from 0 to 25 mmwidth or diameter. The Model 3475 has an armthickness of only 3.81 mm, and will work simul-

taneously with any axial extensometer havingsufficient clearance between arms (not all ver-sions of the 3442 miniature extensometer canbe used). Large radius contacts prevent the unitfrom digging into the samples. This model utiliz-es a dual flexure design, allowing use in dynam-ic applications. All units have measuring rangesin both directions.

Features• May be left on through specimen failure.• Rugged, dual flexure design for also cyclic

testing at higher frequencies.

Technical Data Series 3475

EN ISO 9513 Accuracy Class 0.5

Measuring Range ± 0.25, ± 0.50, ±1.00, ± 1.25 mm

Linearity Error incl. Hysteresis 0.15 % (± 1.25 mm 0.20 %)

Operating Temperature - 265 °C up to +175°C

Dimensions Flat Specimens ❏0 - 25 mm

Dimensions Round Specimens Ø 0 - 25 mm

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They are weight-compensated and mountedin smooth-running guides. The two measuringarms apply the lateral change to the measur-ing springs with their integrated full bridgestrain gauges. Pneumatic cylinders allow toretract and swing them out of the way. Theposition of the measuring arms remains con-stant during the equally applied extension ofthe specimen. The position of the measur-

ing arms remains stationary relative to thespecimen during the uniform elongation. Themeasuring arms are always dragged togeth-er with the specimen. The pressing force ofthe measuring arms is very faint, and a hinge

Automatic Transversal ExtensometerSeries MFQ - A

Specially designed for the determination of the r-value (vertical ani-sotropy) of fine sheet metal specimens. Equipped with two measuringclamps, forming the average value of two separate measuring locations.

mechanism with all degrees of freedom linesitself up very gently, therefore very thin sheetmetal, down to 0.2 mm can be measured. TheMFQ-A is automatically brought into con-tact with the specimen utilising a pneumaticsled. When uniform stretching is completed,this movement is reversed, to swing the unitout of the way. An electronic controller boarddrives the MFQ-A from the PC.

Pressure of the measuring pins 2N. Pressu-rised air consumption ca. 1 l / min. Pneumaticworking pressure ca. 4 bar.

This model is for general purpose diametralstrain measurement and is often used onhourglass specimens where a normal axialextensometer won’t work. Quartz rods andwater cooling allow the unit to be used forhigh temperature testing of metals, ceramicsand composites. With induction heating, thismodel often can be used without water cool-ing. When used in furnaces, the extensome-ter is often mounted directly on a flat on theside of materials testing furnaces. Alternately,load frame mounting brackets are optional-ly available for supporting the extensometer.Quartz rod lengths are made to fit furnaces

High Temperature Diametral ExtensometerSeries 3580Designed for transverse or diametral strain measurements at temperaturesup to 1000°C. For use with furnaces having a side entry slot or with induc-tion heating systems. They utilize a proprietary, rugged dual flexure design.

as required.

Features• May be left on through specimen

failure.• Rugged, dual flexure design for

strength and improved performance.Much stronger than single flexure de-signs, this also allows cyclic testing athigher frequencies.

• Optional versions for use in vacuumenvironment.

• Special rods for large specimens.

Technical Data Series 3580EN ISO 9513 Accuracy Class 0.5

Measuring Range ± 0.5, ± 0.75, ± 1.5, ± 2 or ± 5 mm

Linearity Error incl. Hysteresis < 0.15 mm

Operating Temperature - 40 °C up to +1000°C

Dimensions Round Specimens Ø 4.5 - 16 mm

Technical Data Type MFQ - A

EN ISO 9513 Accuracy Class 0.2

Measuring Range 4 mm (6 mm optional)

Linearity Error incl. Hysteresis 0.05 %

Dimensions Flat Specimens Width 13, 20, 25, 30 mm

Dimensions Flat Specimens Thickness 0.2 - 10 mm

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Specially suitable for measurements during dy-namic tests, particularly on polymers and othermaterials with relatively large strain. The SeriesVEX Video Extensometers are contact-less op-tical measurement systems based on a singlecamera and real time image processing.

High Resolution Type VEX 50for the simultaneous measurement of longitu-

dinal and transversal strain in tension e.g. tests.It measures the strain between two appliedlines with a rate of up to 50 Hz. The specimen’sdeformation is measured contact less and e.g.stress-strain curves, E-Modulus and Poisson’s

Digital Video ExtensometersSeries VEXFor the simultaneous measurement of longitudinal and transversalstrain in tension e.g. tests or as high speed version with 4000 Hz (4 kHz)measuring range.

ratio are determined. The strain data is trans-ferred to the digital controller for closed loopstrain control or data acquisition.

High Speed Type VEX 4000High speed version with 4000 Hz (4 kHz)measuring range. This unit is specially suitablefor measurements during dynamic tests, par-ticularly on polymers and other materials withrelatively large strain.

AccessoriesSample marking machine, backlight, mountingbracket for testing machine and portable tripod.

Technical Data VEX 50 VEX 4000

EN ISO 9513 Accuracy Class 0.5 0.5

Strain Range max. 500% 500%

Strain Resolution 0.002 % 0.02 %

Measurement Rate max. 50 Hz 4000 Hz

Spatial Resolution of measuring field max. 1x10-6 1x10-6

The Model 3550 extensometer is most often

used on round specimens tested in bi-axialtest machines capable of simultaneous axialand torsional loading. The extensometer is of-ten customized for particular applications. Allunits are capable of bi-directional displace-ment, so they may be used for cyclic testingunder fully reversed loading conditions. Thestandard sized model is self-supporting on thespecimen, and works on specimens from 9.5to 25.4 mm. The included conical point con-tacts are made from tungsten carbide. Their

Axial / Torsional ExtensometerSeries 3550For simultaneous measuring axial and torsional deflections on specimenstested in axial / torsional machines. All units are capable of bidirectionaltravel, so they may be used for cyclic testing under fully reversed loads.

unique design directly measures the surface

shear strain angle, which allows operation ona wide range of specimen diameters withoutchanging calibration. All models are designedspecifically to minimize crosstalk between axesand to provide high accuracy measurements.A wide range of gauge length and measuringranges are available. Because these transduc-ers are often used for specialized tests, contactus with specific test needs.Operating force < 30g typical.Crosstalk <0.5%.

Technical Data 10-05-04 12-20-02 25-05-02 25-05-03 25-10-02

EN ISO 9513 Accuracy Class 0.5

Axial Gauge Length 10 mm 12.5 mm 25 mm 25 mm 25 mmAxial Measuring Range ±5% ±20% ±5% ±5% ±10%

Torsional Shear Strain Angle ±4° ±2° ±2° ±3° ±2°

Linearity Error incl. Hysteresis <0.15

Operating Temperature -40°C up to +100°C or Option - 265 °C up to +175°C

Dimensions Round Specimens Ø 9.5 - 25.4 mm

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For fracture mechanics studies, these gaugesare in compliance with standardized test meth-ods, such as ASTM E1820 for determination offracture toughness properties of metallic ma-terials. These gages conform to the require-ments of ASTM E399 for fracture toughnessand E1820 and E813 for JIC and R-curve de-termination. In addition, the modified groovedesign complies with E1820 tests where great-er stability and accuracy results from the sharp-er groove root. Clip-on gauges are used for avariety of fracture mechanics tests, includingcompact tension, arc shaped, disk shaped,bend specimens or other specimen geometriesin compliance with ASTM and other standards

Fracture Mechanics Clip-On GaugesSeries 3541For fracture toughness testing according to ASTM E1820 & ASTM E813.Used for a variety of fracture mechanics tests, including compact tension,arc shaped, disk shaped, bend specimens or other specimen geometries.

organization’s test methods. Clip-on gages canbe used directly on test specimens where theknife edges are integral with the test specimenor, alternately, with optional bolt-on knife edg-es mounted on the test specimen.

Features• Accuracy according to ASTM• Fully enclosed gages to protect from

accidental damage.• Sharp grooves per ASTM E1820, E813,

and E399 for improved stability whenmounted.

• All capable of high frequency operation(50 Hz or faster, depending on version).

Crack Mouth Opening ExtensometerSeries EXRUsed to determine material characteristics R-Value, JIC and KIC. Suitablefor tensile, bending, and fracture mechanical tests on specimens, originalcomponent parts, and assemblies of any configuration.

Crack mouth opening values are assigned viacalibration curve, crack length values used todeter- mine material characteristics R-curve,JIC, and KIC. EXR - Extensometers are suitablefor tensile, bending, and fracture mechanicaltests on specimens, original component parts,and assemblies of any configuration.It is ideally suited for J-integral tests withlarge gauge length and range of measuring

displacement. Adjustment to the specimen issimple but precisely. The extensometer can beclip on to either knife edges screwed to speci-men or to machined specimen edges.

Technical Data Series EXR

Standard Initial Gauge Length 5 - 30 mm (in steps of 5 mm)

Measuring Range 0.25 - 10 mm

Linearity Error incl. Hysteresis 0.25 - 0.3%

Technical Data Series 3541

Standard Initial Gauge Length 3, 5, 8, 10, 12 or 20 mm

Measuring Range +2.5/-1, +4/-1, +7/-1, +10/-1, +12/-2 mm

Linearity Error incl. Hysteresis 0.15 (for < 6 mm), 0.20 (rest)

Operating Temperature -265°C up to +175°C

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Water-cooled and furnace bracket mount-ed, these are for use to 1200 °C . The hightemperature option allows use to 1600 °C .These COD gages mount on a water-cooledbracket which is mounted on the furnace sidecut-out or with optional load frame supportbrackets. The standard temperature version(to 1200 °C) is supplied with high purity alu-mina rods. The high temperature option is fur-

nished with alpha grade silicon carbide rods.Rods are made to order to the length requiredfor your furnace. Mounting brackets may beintegrated with the furnace cut-out. w+b canalso provide optional load frame mountingbrackets to fit your test frame. Contact edg-

HT Fracture Mechanics Clip-On GaugesSeries 3548 CODFor fracture toughness testing according to ASTM E1820 and ASTM E813.For use in split type materials testing furnaces with a slot for the ceram-ic rods for temperatures up to 1200 °C, optional up to 1600°C.

es on the test sample should be somewhatrounded (not sharp knife edges) for best per-formance with this model.

Features• Accuracy according to ASTM• Rugged, dual flexure design for strength

and improved performance.• All units operate in tension and

compression.• Includes high quality foam lined case

and a spare set of ceramic rods.• Optional load frame mounting brackets

These gages are designed for testing at ele-vated temperatures, much higher than straingage based clip-on designs. They can be usedfor several standardized fracture test meth-ods, including ASTM E399 for fracture tough-ness or E1820 and E813 for JIC and R-curvedetermination. The Model 3641 uses a hightemperature capacitive sensor and can oper-ate without any cooling at the upper temper-ature limit of most environmental chambersused in materials testing. High temperaturenickel alloy springs are used to create theforce to hold the gage in place on the knifeedge contacts. Stiff arms with a flexure de-sign at the rear eliminates potential problems

HT Un-Cooled Fracture Mechanics GaugesSeries 3641HT clip-on gauges for fracture mechanics tests in environmental chamberswhere the entire gauge must be exposed to the heat. These capacitive sen-sor based clip-on gauges may be used up to 540°C without any cooling.

of high temperature creep experienced withother designs.

Features• Accuracy according to ASTM

requirements.• Sharp grooves per ASTM E1820, E813,

and E399 for improved stability whenmounted.

• Rugged design provides dynamic test-ing capability to 20 Hz or faster de-pending on version.

• Recommended for elevated tempera-ture testing in air or some other gases

• Operating force 9 - 14 N.

Technical Data Series 3548 COD

Standard Initial Gauge Length 5, 8, 10, 12 or 20 mm

Measuring Range ±2.5, ±4, ±7, ±10 or ±12 mm

Linearity Error incl. Hysteresis < 0.15%

Operating Temperature Ambient up to 1200°C or up to 1600°C as Option

Technical Data Series 3641

Standard Initial Gauge Length 3, 6, 10, 12 or 12.5 mm

Measuring Range +3, +6, +10, +12 or +12.5 mm

Linearity Error incl. Hysteresis < 0.10%

Operating Temperature Ambient up to 540°C

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64 Accessories for Materials TestingEXTENSOMETERS

The electric potential growth technique is noncontaminating and can be used in most en-vironments specially inside an environmentaltest chamber. Visual method generally are notpractical, often, the crack and the test speci-men are obscured by the test chamber or amicroscope with a long facial length needed.The technique involves passing a constantcurrent through the metal under test and

measuring the resultant voltage drop that iscreated across the specimen. The presence ofa growing defect will alter this voltage and by

Potential Drop Crack Growth MonitorSeries DMCMicroprocessor based instrument for measuring crack depth in metals un-dergoing materials testing. Uses the Pulsed Direct Current Potential DropMethod (DCPD) which is an established technique covered by ASTM 647.

suitable calibration, a measure of the defectdepth can be obtained.

Features• Capable of reverse and pulsed DCPD.• Advanced filtering and sampling, trig-

gering including peak, trough, and mid-point of load cycle waveform input.

• Variable DC offsets for the removal of

standing voltage.• Two channels as standard, reference

and specimen.