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The condition monitoring magazine of PRÜFTECHNIK AG and Flender Service GmbH

No. 06 - April 2004

Condition monitoring application in Brazil:

Housing crack on a bucket-wheel excavatorDr. Edwin Becker, Flender Service

Future issues of telediagnose.com willbe dedicated to a particular industry.The last issue dealt with the subject of“Wind power”. This issue focusses onstrip mining and material moving tech-nology. Increasingly, this industry is us-ing variable speed drives which in turnrequire modern and high performancediagnostic algorithms.

PRÜFTECHNIK and Flender Servicehave obtained techniques, methods anddiagnosis algorithms after intensive de-velopment work for Condition Monitor-ing of dynamic speed wind energyplants, which in future will provide newinnovative diagnosis possibilities in oth-er industry branches. ■

A gearbox of a bucket-wheelexcavator suddenly lost oil aftermany years of trouble-free op-eration due to cracks in thehousing. Attempts were madeto weld the cracks and to carryout vibration analysis, all with-out success. The cracks in-creased and more oil leakedout. An identical replacementgearbox was mounted. The un-usual cracks also appeared inthe output area of the housingof the replacement gear. Flend-er Service was commissioned tosearch for the cause of thesehousing cracks in the largest iron oremine in the world. Mobile torque mea-surements and targeted system analysison site identified overloads and housingtensions as the cause. The recommend-ed measures to strengthen the excava-tor and gear were carried out togetherwith Flender Brasil.

But one step at a time: Bucket-wheelexcavators are being used around theworld for strip mining and materialmoving technology to continuously ex-cavate and load material and bulkgoods. In bucket-wheel excavators, thegears mostly “ride” on the bucket wheeland, as well as matching the motorspeed to the bucket-wheel speed, havethe task of directing the torque safely tothe supporting structure.

The motor is directly mounted on thetorque support of the gear. The activeforces on the bucket wheel from theswivel motion have to be taken up by thegear housing.

The excavator performancethat is achieved increases inthe case of loading excavatorsif the bucket-wheel speed and/or the bucket-wheel volume isincreased. This results in in-creased static load for the ex-cavator and also additional de-formation, tilting and strain inthe entire bucket-wheel head.Sometimes there can be ex-tremely high dynamic addi-tional loads which can only beproven by highly sensitive

torque measurements. Based ontheir experience, Flender ServiceCondition Monitoring immedi-ately offered the Brazilian mineoperator systematic torque mea-surements to identify the sourceof the problem.

The figure on the left showsthe installation of a torque mea-surement location on the bucket-wheel shaft in the Brazilian rain-forest. Despite extreme iron orecontamination, strain gageswere carefully mounted and themounting of a telemetry for thetransmission of non-contact

measured values including the Drive-Analysator® continued until late in thenight. The measurement cables werethen fed into the driver’s cab and con-nected to the notebook computer for

Use the synergy of telediagnosis

telediagnose.com magazinenow always industry-specific

In this issue:telediagnose.com magazine nowalways industry-specific

Housing crack on a bucket-wheelexcavator

Online vibration diagn. & load mon-itoring on bucket-wheel excavators

Uniting information systems withWeb services

Easy: Monitoring contact patternson bevel gear stages

Incredible: Resonances and theirenormous power

News & fair dates

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The condition monitoring magazine

evaluation. The torque measurement lo-cation itself was calibrated using a shuntresistor (Figure 2).

Before taking the measurements, itwas agreed to mount a new gear inorder to exclude the effects on the mea-surement signals of any preliminarydamage to the gear. Figure 1 shows themounting of the gear.

The following day, the first measure-ment results already showed extremelyhigh loads which, during excavation inthe upper crust, even exceeded the safe-ty torque (picture 3). The hydrauliccoupling mounted as a safety couplingdid not separate; Here, the oil filling wasincreased after employment of new larg-er buckets. However, what was the useof detecting increased loads? The causeof the cracks had to be found and thestabilization measures determined. Afterall, the delivery rate of the excavatorwas supposed to be increased.

The disassembled bucket wheel gearwas examined more closely. A red-whitetest on the housing revealed that therewere further cracks in the area of theinternal gear of the drive planetarystage. The planetary stage of the oldgear was targeted for inspection as thenext step. Unbalanced tooth damage onthe internal gear of the planetary stagewas a visible indicator of uneven lateralsupport in the planetary stage. Figure 5shows an FEM model from the BochumRuhr University of how tilting can occurin bucket-wheel gears of this type as aresult of the intrinsic weight and as aresult of lateral forces during excava-tion. This tilting causes local overloadswhich, in Brazil, led not just to unevenlateral support, but also to housingcracks. In the past, Flender Service hasgathered extensive experience, especial-ly in bucket-wheel excavators for browncoal technology.

The operator was recommended tostrengthen the gear in the vicinity of theplanetary stage. The integration of atorque support in the bucket-wheel ex-cavator should be constructed so that,during the swivel action, there are nowarping or tipping forces on the gearhousing and, particularly, on the teeth ofthe planetary stage.

®

Since then, a year has passed. Themodifications were implemented andhousing cracks no longer appear. Thelarger shovels used by the operator haveincreased the delivery rate as desired. ■

Figure 1: Mounting the replacement gearon the Brazilian bucket-wheel excavator

Figure 3: Example oftorque measurementover 2 minutes

Figure 2: Calibration of the strain gagesmeasurement location

Figure 4: Unbalanced tooth damage onthe internal gear

Figure 5:FEM model of bucket-wheel gear

Planetarystage

Bucket-wheel shaft

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The condition monitoring magazine

PRÜFTECHNIK Technologie

Online vibration diagnosisand load monitoring on bucket-wheel excavatorsMathias Luft, PRÜFTECHNIK

In four active surface mines in theLausitzer brown coal mining district, theVattenfall Europe Mining AG mines 59.3million tons of raw brown coal (status31.12.2002). This represents 33% of theGerman brown coal requirement.

For years, the main aggregates such asbucket-wheel excavators, belt stackersand belt drive stations have beenequipped with systems for operative di-agnosis in the early detection of prob-lems in mechanical and electrical units.

Currently, the main drives of buck-et-wheel excavators are changingover to a standardized concept.This opportunity can also be usedto upgrade the systems for onlinevibration monitoring as an integralpart of the operational diagnosis.

The practical implementation onone of the two largest bucket-wheel excavators is described atthis point.

Operating conditionsIn the part cut, bucket-wheel ex-

cavators are used for the removalof the first tailing stage. The ag-gressive loads on the bucket wheelcan be particularly problematic,e.g. if the soil properties changefrom sandy soil to a strong loamysoil or larger boulders are excavat-ed. In addition to the monitoring ofthe rolling bearings and meshingsof the main bucket-wheel drive,therefore, the acquisition and mon-

itoring of the highly dynamic changingloads has special significance.

The main drive of the bucket wheel ofthe large excavator being monitored hastwo drive motors, each with 1250 kWdrive power and gear which weighs ap-prox. 80 tons (Fig. 1). The gear reduc-tion of each drive is realized by a bevelgear stage and subsequent planet gearstage with load distribution via a turningstage. This transfers the drive torque tothe gear via four pinions and further to

the bucket-wheel shaft via the hollowshaft (Fig. 2).

Torque monitoringon the displacement bolts:

The digging forces place a strain onthe buckets and, thus, the drive torquesof the gear which are supported on thebucket wheel bearing and on the dis-placement bolt that acts as the torquearm of the gear. A feature of the onlinemonitoring installed is the measurementof this torque on the displacement boltwith the aid of a strain gage measure-ment bridge (Fig. 3).

As soon as larger or even unacceptablyhigh torque peaks occur, the correspond-ing time domain of the torque signal ispre-triggered and post-triggered, and

saved together with the curve of theload, speed and the displacements withprehistory and posthistory. This is car-ried out by an automatic event recordingfunction. If necessary, the saved eventcan be examined more closely (Fig. 4).

Wear monitoringon the bearings

of the driven shaftThe main monitoring task on the very

slow-speed roller bearing drive shaft(3.6 rpm) is the detection of criticalwear limits. For this, two inductive dis-placement sensors were installed at lessthan 90 degrees on each of the two sidesto directly monitor displacements due tochanges in load and increased amountsof play.

Bucket wheelshaft

Figure 2: Bucket wheel main drive 2x 1250 kW

Bucket wheel

Displacementbolts

Hollow shaftgear

Figure 1: 80 ton gear on the main drive of thebucket wheel

Fig. 3: Torque measurement

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Glossary of termsDid you know?

Web serviceA Web service provides services via networks(LAN, Intranet, Internet). W3C protocols areused for communication and support. Thespecial feature of Web services is that theyare generically compatible and mesh withone another because they all use the sameopen standards for communication.

W3C (World Wide Web Consortium)The definition of the Internet protocol ismade by the independent World Wide WebConsortium (W3C), which, in addition to Sun,IBM, Microsoft and Apple, includes a further400 companies and institutions.

W3C Web Service UDDI protocol(Universal Description, Discover, Integration)for the publication, finding and integrationof Web services.WSDL (Web Service Description Language)For the descriptions of Web services.XML (EXtensible Markup Language) is thenotation for the transport of data.SOAP (Simple Object Access Protocol) forXML-coded calls of Web services.HTTP / SMTP (HyperText Transmission Proto-col / Simple Mail Transmission Protocol) is thetransport protocol of the Internet.TCP/IP (Transmission Control Protocol / Inte-net Protocol) is the network protocol of theInternet.

Web service securityFor the transport security of Web serviceswithout additional hardware costs, SSL (Se-cure Socket Layer) encoding with codelengths of up to 1024 bits is available. Fire-walls and VPN routers can also be usedwithout any problem. Access to Web servicescan be individually restricted according touser or user group.

JAVAJava is an object-oriented and platform-inde-pendent programming language that wasintroduced by Sun Microsystems in 1995.Meanwhile, it has become the standard pro-gramming language for web-capable soft-ware. Meanwhile, leading software co-mpanies such as SAP and MRO (MAXIMO)have changed over to JAVA.

JAVA WebstartJava Webstart is a new technology by whichJava software can be distributed from a cen-tral location (Server) to the user PCs (Clients)where they can be continuously updated. Assoon as a user connects with the server, JAVAWebstart automatically checks that all neces-sary program parts are available and wheth-er they are up to date. If necessary, therelevant parts of the program are automati-cally transferred to the client and storedthere.

Monitoring of the rollingbearings and meshings

Vibration transducers have been in-stalled on the motors, gear input stagesand intermediate shafts to monitorthem.

In addition to frequency-selectivecharacteristic vibration values, the on-line system at regular intervals alsosaves a complete set of in-depth diag-nostic signals (time signals, amplitudespectra, envelope spectra) that are onlymeasured at representative load andspeed. This furnishes the diagnostic spe-cialist with a current set of data at anypoint in time, even when the bucketwheel excavator is not currently in oper-ation.

If an alarm occurs, the operation mon-itoring is automatically immediately no-tified. A complete set of in-depth diag-nostic signals is also measured at theaffected measurement points in order tolater evaluate the cause of the alarmwith the details of the event.

System connectionThe central measurement system is

located in the VIBRONET® control cabi-net immediately behind the main driveand connected via fiber optic cable withthe factory-wide Vattenfall network.This network also enables PRÜFTECH-NIK to access the online system at anytime. ■

Figure 4: (1) Period for a revolution of the bucket wheel(2) Periodic engagement of the buckets at negligible load(3) Transient drop in speed due to heavier torque loads

DisplacementInductive displacement sensors on thehollow shaft

VibrationAccelerometers on rolling bearings

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The condition monitoring magazine

New technology

Uniting information systems with Web services

PreviewOur next edition covers the main fieldof extruder technology:

CM application: Reducing vibrations ontwin-shaft extruders

CM technology: (Remote) Monitoringof oil qualities

CM application: Vibration monitoringvia the Internet on the world’s largestsingle-shaft extruder in Malaysia

CM application: Alignment of high-speed extruder drives

Roland Schühle, PRÜFTECHNIK

Firstly, in order to understand theadvantages of this new technology, theuser must be aware of the problem:

For example, in many of today’s main-

tenance departments, machine and sys-tem data are still entered in Asset Man-agement systems and in Condition Mon-itoring systems. In addition to the highexpense of maintaining both sets ofdata, the responsible maintenance engi-neer must also be trained in the respec-tive software packages. However, net-working both systems can only be real-ized with high programming expensesand covers only a small part of thenecessary functionality.

Then if external diagnostic specialistsare also integrated, it is difficult for themaintenance engineer to integrate mea-surement results and reports (which aremostly supplied on paper) into the exist-ing data systems.

A solution to this problemcould be as follows

The maintenance engineer works withone software program, and data whichare entered only once such as assetnames, bearing data, measurement re-sults or diagnostic reports are availablein all systems. In the ideal case, themanufacturer, operators, maintenanceengineers and service all use the avail-able machine, service and diagnosticinformation for their planning and deci-sion-making. For the respective subareasof a company, there is a multitude ofspecialized information systems• Condition Monitoring Database Sys-

tems (CMDS)• Operating Data Recording Systems

(ODRS)• Condition-Based Maintenance Sys-

tems (CBM)• Service Management Systems (SMS)

• Maintenance Planning and ControlSystems (MPCS)

• Production Planning Systems (PPS)• Asset Management Systems (AMS)• Enterprise Resource Planning Systems

(ERP)• Knowledge databases and expert

systemsHowever, any interdepartmental or

site-wide integration of the informationsystems mostly fails due to the hightechnical demands and the negligibledegree of standardization. In some cas-es, data must be transferred manuallybetween the systems so that the respec-tive projects frequently fail due to a lackof acceptance by the users.

Naturally, these problems are not newand in the past there were a number ofsolution approaches such as Corba.However, unlike the Internet, none ofthese solutions became a general stan-dard.

In the Internet,the most varied in-formation can becalled in the formof HTML pages. In-formation such asimages, tables andtexts can be easilyabsorbed by theuser, even if some-thing changes inthe design of thepage in the mean-time. However, forcomputers, suchchanges would have been fatal until nowas their software would first have to beadapted.

To solve this problem, the new Inter-net protocols SOAP, WSDL and UDDIwere defined by the World Wide WebConsortium (W3C) that together withTCP/IP, HTTP, SMTP and XML form thebasis of Web services.

Web services create a system-indepen-dent communication level on which themost varied databases and services canbe linked via existing network comput-ers to form an information system. Atthe same time, it does not matter howthe data are saved on the individualsystems and in which programming lan-

guage the system is realized.Meanwhile, Web services are available

in all common programming languagesand already integrated in several datamanagement systems. Web services canbe realized at low cost as the technicalrequirements are low, and the hardwarefor it does not have to be renewed andmost systems are networked anyway.

In the areas of Asset Management,Resource Planning and Condition BasedManagement, Web services are also al-ready integrated in the following prod-ucts:• MAXIMO® from MRO,• mySAP ERP® from SAP• FLEDAS® from FLENDER• OMNITREND® from PRÜFTECHNIK

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The condition monitoring magazine

6Fig. 4 Contact patterns of bevel drives can be adjustedFig. 3 Ideal result of the contact

pattern check

Level 1 Condition monitoring experiences

Easy: Monitoring contact patterns in bevel gear stages

Bevel gears are readily used in materi-als handling technology if the crossedbearing of the drive and output shaftsoffers advantages over the parallel ar-rangement. In the case of bucket wheelmain drives, the so-called shear angle isgreater and, in belt drive stations, verycompact belt drives with drive powersup to several MW can be constructedusing bevel/helical gears as shown inFig. 1. The disadvantage of bevel gearsis that the bevel pinion is mostly cantile-vered, reducing the contact pattern,transmission performance and balance.Consequently, in the case of gears withbevel gear stages, the meshing fre-quency of the bevel gear stage oftendominates the vibration and noise spec-tra which also means, however, that therunning and operating characteristics ofbevel gear stages can be very well moni-tored with regard to vibration.

Fig. 1 shows the three typical mea-surement points required to estimateinformation on the current operatingand vibration response of bevel gearstages. Naturally, a stable sensor con-nection and the use of sufficiently highmeasurement times are important.Therefore, before making any mobilemeasurements, check the adhesive forceof your magnets. Any dirt must be re-moved and the sensor must not tilt.Both amplitude spectra of the vibrationvelocity and envelope spectra should beused as diagnostic procedures. A mini-mum measurement time of 10 secondsand a frequency resolution of 8100 linesin the frequency range up to 3 kHz mustbe used to also safely resolve sidebands.If the amplitudes in the meshingfrequency and/or in the harmonics thenchange over the operating time of thebevel drives, the contact pattern hasmost certainly shifted to the bevel drive.However, in bevel gears, a good contactpattern is the crucial requirement for along lifetime. So if there are changes inthe vibration spectra, the vibration diag-nosis should be complemented by aninspection of the contact patterns and, ifnecessary, the flank clearances in-creased. Fig. 3 and Fig. 4 show correctcontact patterns of bevel drives. If thetooth patterns in the bevel drive do not

Dr. Edwin Becker, Flender Service

look like this, actions such as axle posi-tional corrections on the bevel pinionand on the ring gear can still be taken toreset the contact pattern. Fig. 4 showsexamples of the measures which can betaken to longitudinally displace the con-tact pattern. The arrows in the middleshow the corrective measures requiredto achieve the optimum contact patternas shown on the right. Before carryingout any new adjustments, however, theamplitude spectra of the envelopeshould be checked. If increased bearingclearance is present in the ring gearshaft and/or in the bevel pinion shaft, abearing change must be planned be-cause, in the case of bevel drives, in-creased bearing clearance very oftenchanges the contact pattern. Increasedbearing clearance is best identified inthe envelope spectra. If pronounced ro-

tational frequency excitations arepresent in the envelope spectra and firstsidebands around the meshingfrequency in the vibration velocity spec-tra, this indicates increased bearingclearance. Moreover, when carrying outcorrections, the module-dependentflank clearances must be kept. For exam-ple, in the case of Module 8, a flankclearance of roughly 0.18 to 0.20 mmshould be kept and, in the case of Mod-ule 16-18, a flank clearance of approx.0.40 to 0.45 mm should be kept. Aftersuccessful correction, the typical ellipti-cal contact patterns are reached againand the vibration values in the vibrationvelocity spectra are lower again. If youdiscover further fluctuations in the con-tact pattern of your bevel drives orincreased vibrations from the beveldrive, contact us at info@flender-cm.de.■

Figure 1: Typical sensor positions during vibration analyses on the bevel drive

Figure 2: Gear with open in-spection hole cover

What to do if the following contactpatterns appear during installation?

Adjustments

Normal contact pattern (see above)should now appear

The diagrams refer to the bevel gear where (v) = forward flank and (r) = rear flank

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The condition monitoring magazine

PRÜFTECHNIK was called in to evalu-ate damage on a supply air ventilator.The site was a scene of destruction anddevastation.

Both pedestal bearings of the ventila-tor shaft had been torn off and hurledaway. The 80 mm thick shaft was bentby approx. 30 degrees on both sides ofthe impeller. The impeller itself had runinto the left and right suction cones,completely destroying them and wasitself badly dented. All fan belts weretorn – in short, this aggregate was a totalwrite-off. What had happened?

An important clue was the evidencefrom the operator who said the damagehad occurred during the startup of theventilator. As a ventilator of the sametype was in operation nearby, it waspossible to record a so-called Bode dia-gram or run up curve. This measurementrecords the amplitude of the rotationalfrequency vibrations (i.e. the part of thevibration caused by imbalance) as afunction of the speed. It revealed a trendthat indicated the crucial circumstantialevidence for the reconstruction of thedamage progression (Fig. 1, right). Atapprox. 1130 rpm, and thus below theoperating speed of 1300 rpm, a suddenrise in the rotational frequency vibrationamplitude to more than 80 mm/s (!!)appeared which then abruptly fell againabove this critical speed. Consequently,the signal path corresponds precisely tothe behavior of a rotor when passing

through its 1st flexing in-trinsic vibration (Fig. 2).In addition to the distinc-tive rise in the rotationalfrequency vibrations, thephase rotation of 180 ° isespecially typical.

It was clear from thisthat only a rotor reso-nance could have beenthe underlying cause ofthe damage. However, theactual cause could havebeen increased imbalanceof the impeller that couldstill have been absolutelypermissible at the opera-tional speed, but causedtoo large a vibration exci-

tation when passing through the reso-nance point.

How high the vibration increases at

Level 2 Condition monitoring

Unbelievable: Resonances and their enormous forceMathias Luft, PRÜFTECHNIK

the resonance point depends mainly onthe damping of the rotor and on thedwell time in the area close to the pointof resonance. Heavy rotors such as theturbine rotors of large steam turbinesrequire more time to build up to highvibration amplitudes than, for example,light impellers. Thus, in addition to theoptimum balance of the rotor, rapidlypassing through the point of resonanceis also a key factor in avoiding unaccept-able vibrations near the point of reso-nance.

Anyway, if the resonance point of therotor is to be shifted, constructivechanges are essential. In this case, thechanging of the rigidity, the mass or thebearing spacing are the most importantparameters although such measures areoften not possible for cost reasons. How-ever, as an additional measure in vari-able-speed aggregates, at least the speedrange close to the resonant frequencymust be blocked in the converter controlunit. ■

Phase shift by 180°

Bode diagram / Startup curve

Resonance

Resonance point1. Bending intrinsic form

A =82.6 mm/sn =1132 rpm

Amplitude curve

Vibration form of a rotor

Resonance

Rise in resonance

Figure 1

Figure 2

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The condition monitoring magazine

Dates

News

PRÜFTECHNIK AG and Flender Service:Visit us at the following international trade shows and exhibitions:

WindEnergy Hamburgwith Flender Service at Booth 240 ofthe Winergy AG in Hall 6 on 11th - 14thMay

PetroTech 2004Rotterdam, Holland, 25th - 27th May

PulPaper 2004Helsinki, Finland, 1st - 3rd June 2004

Practical seminar: “Condition Moni-toring for the wind energy industry”with PRÜFTECHNIK and Flender Ser-vice on 18.06/ 19.06 in Rostock andon 01.09/02.09.2004 in Hamburg

Special seminar “Modern Gear Ser-vice“with Flender Service in Damascus/Syriaon 26.04 and 28.04.04

Zellcheming 2004Wiesbaden, 28th June - 1st July 2004

SMM 2004Hamburg, 28th September - 2nd Octo-ber

VDI conference “Electromechanicaldrive systems”with Flender Service in Fulda on 06./07.10.2004

GearController®

for M/Y ‘Limitless’Flender Service supplied two Gear-

Controller® units and the OMNITREND®

software for the online monitoring ofthe gear and bearing conditions of oneof the 10 largest private yachts in theworld. Mounting and commissioningwere required at very short notice andwere immediately carried out on theBaltic sea by specialists of Flender Ser-vice and PRÜFTECHNIK Condition Mon-itoring. ■

PRÜFTECHNIKreorganizes domestic sales

The constantly growing range of prod-ucts and ever growing demands in tech-nical sales made reorganization of thePRÜFTECHNIK domestic sales divisionnecessary, with the specialization of thesales team to a product segment each(Alignment or Condition Monitoring).Also in the future PRÜFTECHNIK cus-tomers can expect more competent tech-nical advice and assistance in solvingproblems. With the reorganization of thedomestic sales division in Germany,PRÜFTECHNIK has strengthened its po-sition in the home maintenance market.■

Relocation to a newCondition Monitoring CenterThe Flender Telediagnosis Center has

also moved into new premises and wastechnologically modernized at the sametime. The move provided Flender Ser-vice with the ideal conditions for tack-ling the impending certification as acondition monitoring center by Germa-nischer Lloyd. ■

AddiControl® foranalysis of oil qualities

Flender Service first introduced theAddiControl® to the general public atthe 14th. International tribology confer-ence in January 2004. The smell of theoil is measured to analyse the type ofgear oil which is used, whether prohibit-ed mixtures of oils are present or wheth-er the additives are still OK. ■

Effective machine protectionwith VIBROTECTOR®

VIBROTECTOR® is theideal vibration monitor forall machines that operateunder almost constant op-erating conditions such as:

■ Fans■ Ventilators■ Pumps■ Electromotors

VIBROTECTOR® recordsbroadband machine vibra-tions and hands over the resulting char-acteristic value to the connected processcontrol system as a current level (4-20 mA). This value is compared with theselected alarm thresholds and, if exceed-ed, warns operating personnel. ■

OMNITREND® goes variableThe new 1.80 version of OMNI-

TREND® now also includes diagnosticfunctions for machines that work withvariable speed and loads:

- Operating conditions- Order spectra- Cepstrum for gear diagnosisDownload your update (free of char-

ge) from www.pruftechnik.com ■

VIBXPERT® – new FFT datacollector & signal analyzer

The new 2-channel analyzer was in-troduced at the Hanover tradefair. Infor-mation is also available on the Internetunder: www.pruftechnik.com. ■

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PRÜFTECHNIKCondition Monitoring85730 Ismaning, Germanywww.pruftechnik.comPhone: +49 (0)89-99616-0Fax: +49 (0)89-99616-300eMail: info@pruftechnik.com

Flender Service GmbHCondition MonitoringSüdstraße 11144623 Herne, Germanywww.flender-cm.comPhone: +49 (0)2323-940-220Fax: +49 (0)2323-940-229e-Mail: info@flender-cm.de

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