Adash 4900 – Vibrio III ffl User`s Guide
Contents
1. User s Guide Whdash a Adash 4900 Vibrio Ill Built in FASIT Expert System Machine vibration diagnostics Bearing diagnostics Lubrication diagnostics Service activities Product Inspection YOUURY onl S mm s RMS FASIT Fault Source Identification Tool see details inside Spectrum FFT analysis Measurement of time signals Built in stroboscope lamp Determination of machine and bearing conditions Detection of speed Wideband measurements RMS or PEAK acceleration g and velocity mm s values Measurement in frequency bands for bearing diagnostics Colour display Simultaneous display of two measured values External piezoelectric accelerometer with 100 mV g sensitivity Overload indicator sensor fault and cable fault indicators Possibility of connecting headphones for listening of vibration Built in torch Simple control by three buttons q ADASH 4900 Vibrio F od pie a a ek ae ae oe en h a r ap a YVOURVRUUVY YEUUGRY Ref No 240709 ADASH Ltd Adash 4900 Vibrio III Contents Why perform vibration diagnostics ccccceeeceeeseeseeeneecnseeeseecesesensseesseensseasesenseonsesonseoenens 4 Vibration Diagnostics Basic INfOrMatiONn ccccseceeseeeeeseeeseeeeeeeeeneeeeaneeoeseeeenseeeenenennenes 5 TUFOG UCONN wiseacwh acute daviiteudoade peters wwarnenatu tied syraaudendadhaaace dae A EA 5 Ee 03d 40 Sc ean a a a eee ee re 5 Machine and bearing condition2. ADASH Ltd Adash 4900 Vibrio lll g 0 5 Spectrum 200 Hz looseness detection AAT FFT analysis of vibrations in the range Allla 2 Hz 200 Hz in mm s RMS with display of 3 found maximum peaks The peaks are ranked according to amplitude vibration size 1 a Time signal for roller bearing diagnosis Measuring of time signal and vibrations in the range 5 kHz 16 kHz in g Displays actual measured time signal and genv value Vibrations in frequency ranges gearbox bearing Measurement of RMS vibration values in the ranges 0 5 kHz 16 kHz in g 1 5 kHz 16 kHz in g 5 kHz 16 KHz in g Fasit expert system The FASIT screen It displays the severity levels of machine faults 1500 RPM ce Further technical and contact information can be found at www adashusa com www adash cz 24 ADASH Ltd Adash 4900 Vibrio III Speed detection and definition After switch on of the instrument the Screen No 1 appears and the automatic speed detection begins It must be said obviously The user can the automatic speed detection switch off in the Menu The determination procedure is displayed as running bar in the bottom of screen The result is also displayed on the bottom aati mm s RMS When the automatic speed detection is not successful see Automatic determination of the machine rotation chapter the last speed value is loaded from the memory and displayed together with the message lt se
3. for correct data acquisition All methods must satisfy the conditions We can choose different procedures for evaluation of the acceleration signal Measured signal can be imagined as a level of the river It flows with appropriate speed and there are little or big waves If we want to measure the stream we can measure the flow per hour or prompt wave s level The value of the flow will be stable and it will change slowly But the wave s levels are unstable because measurements have significant variety of values The similar effects occur for bearing condition measurements You can measure RMS value the total energy in signal or PEAK value the highest peak in signal We can use both types for evaluation just have to realize of advantages and disadvantages RMS measurement advantages stable and well repeatable time trends are well readable disadvantages if wear increases the response is slower then PEAK but sufficient for maintenance PEAK measurement advantages fast response for any condition change disadvantages not stable and well repeatable extremely sensitive time trends are not well readable From these two basic measurements further measurements are derived Jenv envelope signal modulation Advantages and disadvantages are in the middle of RMS and PEAK measurements gse BCU SEE SPM measurements are performed usually on the sensor resonance frequency These methods have the same advantages and di
4. 4 5 C D Flexible F24 2 3 A B 4 5 B C 7 1 C D Values setting in A4900 Vibrio Ill unit It s possible to set up these values directly in the unit Then the measured values are displayed in traffic light colors You can choose Adash limits recommended or 10 816 limits Setting up is in menu under the mode SETUP see instrument operation Colored marks according 10 816 are range A and B is displayed by green color Range C is amber and range D is red It s necessary to choose a type of evaluation R13 F13 R24 or F24 see table above 15 Further technical and contact information can be found at www adashusa com www adash czZ ADASH Ltd Adash 4900 Vibrio III Quick Start The aim of this chapter is to introduce you to this instrument and without reading a complete User s Guide enable you to measure first vibration values This chapter does not intend to fully and in detail describe operation of this instrument or measurement methodology Special chapters in this Guide are intended for this purpose Preparation of Measurement Point We have to select a measurement point before the measurement itself We want to choose it in such way that transmission of vibrations would not be attenuated Usually this means as close to the source of vibrations as possible for instance at a bearing housing We always have to measure at solid firm part of a machine We should not be measuring on covers and so on The place should be clean w
5. the probably the mechanical looseness is the machine problem The most common causes of this defect are soft flanges loose anchoring bolts cracks in frames cracked welds free play in rotational part seating or possibly other problems not related to mechanical looseness bent shaft See also FASIT chapters Time signal for bearing condition evaluation e STIS g EM 9 The time signal of bearing vibrations is displayed geny value is under the time signal envelope modulated signal see Methods for ball bearing condition diagnostics chapter Caution the time signal is displayed as a direct record not after envelope modulation Look at three basic screens for easy work with this function Undamaged bearing This bearing generates a low amplitude noise only whose time record shape is steady E D J 0 6 agi 0 16 It s necessary to have a look on the range of the graph left side Signal could look high but it s not when the graph range is low for instance 0 5 g 34 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Undamaged bearing wrong lubrication The time record shape is steady too but it has bigger amplitude then previous case ullll J p 10 g ENW 0 59 You can clearly see different bigger range of the graph 1 0 g Damaged bearing There are clearly visible shocks ca
6. GIAQNOSTICS cece cece eecc eee eeeeeeeeeeceeese esse eeseeeaeeeaeesaeeees 6 Methods for ball bearing condition GIAGNOSTICS cece cece eeccceecceeeeeeeeeeeeeeeeeseeeeeeeseeeeeeeeaes 6 The relation between gears and ball DE AriNGS ccccceeccseccseeceeeceeeseeeeeeeseesaeeeeeeeeeseeeeaess 6 FAST Fault Source Ide ntiiiGatlon NOG errn 7 Measurement POINTS sieune vieow nt a view dar un EEEE EA NARE RE RATE EE T The preparation of the measurement POINK ccc ceecceecceeeteeeceeeeeeeeeeeeseeeeeteeeteeeteeneeenaees 8 Listening to Vibrations Using Headphones cccccceccceeeceeeeeeeeeeeeeeeeeeeeeeaeeeseeseeeaeeeaeeees 9 Relationship of Measuring in Acceleration and Speed ccccccsecceeeeeeeteeeteeeeeeeeneeaeeeeees 9 Abbreviations used in the Quide ccccccccecccsecceecceeecuecauecauecauecacecaeecseecueeceeseeeseensensaeess 9 What Will You Get with Your Instrument cceceeeeeseeeeeeceneeeceseeeeeaseeseeseeseanseseeseenes 10 Hsrumentand ACCESSONMES soci edi etic to ashsaa E a cc nadaneet acide auhe nee ateantase teste aes 10 Before VOU Stall aora a E a a a 11 Standards for vibration measurements ccceeeeeeeeeeeeeeeeeneeeeenseeseaseeeeenseeeoaneeseaneeseonaees 12 Adash Limit Values of Machine and Bearing Vibrations ccccccccsececeeeeeeeeeeeesaeeeneees 13 ISO 108 16 IMEVA UGS ea a a 14 Classification according to machine type nominal pow
7. a hardened surface layer in the place of a rolling element contact with a bearing ring regular shocks contamination of bearing space by metal particles irregular shocks cracks The shocks that cause these defects are also parts the RMS vibration values However the peak value of such shock is hidden in a value which contains all other information about vibrations i e noise from possible abrading wrong lubrication and overloading To simplify the RMS is an average value of all vibration values achieved in certain time If a large peak value one shock appears in this time period it will be lost in the final recalculation of all the values This practically means that during increasing of this bearing defect that causes the shock the PEAK value of this shock will visibly increase while the effective RMS value will increase only slowly We can discover the initial defect time of the bearing sooner But PEAK value is not so stable as RMS value For bearing condition measurement is the RMS measurement sufficient Spectrum 200 Hz Detection of Looseness This screen is important for detection of the the mechanical looseness When the graph shows a number of lines typically 3 or 4 with the same space between them and the first line is on the speed 33 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio lll frequency see the value description in the bottom
8. for overall machine condition and you search unbalance misalignment and mechanical looseness above all They are called overall because we can measure them on most of the measuring points Second figure contains the limit values of a roller bearing condition This state is local and can be measured only on appropriate bearing house Work with figures is simple Its necessary to know the speed Instrument determines it automatically or user can enter it manually On the bottom horizontal axis you should find the point which corresponds with speed Above this point you will find an intersection with orange and red graph Projections to the vertical axis will determine limit values for amber or red state If the measured value is lower than amber the state is GOOD green If the value is above amber but under red then the state is ALERT amber If the value is higher then red graph then the state is DANGER red 12 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio lll Adash Limit Values of Machine and Bearing Vibrations Graphs according to which the instrument determines acceptable vibration limits depending on machine speed 6 0 0 24 5 0 0 2 A A D 4 0 0 16 oc o oc z 2 3 0 0 12 T m ma O O Fi S 2 0 0 08 z i p 1 0 0 04 0 0 0 0 5
9. g sensitivity The instrument is equipped by its own source of ICP power for connected sensor The sensor needs to be connected at the right input plug by a supplied cable T i Ai ADASH 4900 Vibrio Fig The instrument with a sensor connected 17 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Connectors connector to plug in the sensor connector to plug in headphones stereo jack 3 5mm Fig Top view of connectors Measuring Screw the sensor onto the magnetic base Do not forget to remove the plastic cover and a metal washer it closes a magnetic field for longer service life of the magnet before measuring Place the plastic cover and the metal washer back on the magnet after measuring Place the magnet on a measuring point very carefully Best is to rest the edge of the magnet on its side and then slowly lower the sensor onto a machine If you bring the magnet near to the machine with its whole area hitting the machine all of the sudden then the strong impact can irreversibly destroy the sensor In case you use a measuring tip instead of the magnet measured values are not going to be stable This in not surprising The measured values depend to a large extent on a pressure of the tip at the measurement point The magnet that attaches the sensor generates a constant pressure so the values are stable Attention Use th
10. 00 1000 1500 2000 2500 3000 3500 4000 speed RPM gt 3 5 3 0 A 2 5 N a 20 T T xX 1 5 x a S S lt 1 0 0 5 0 0 0 1000 2000 3000 4000 5000 6000 7000 8000 speed RPM gt 13 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III ISO 10816 limit values There is a wide range of valid standards but we would like to mention ISO 10816 It has several sections and it also deals with procedures how to gain limit values for particular machines It contains 3 tables of values which are applicable for A4900 Vibriolll unit Classification according to machine type nominal power or shaft height Therefore select the Group that best describes the general size type and speed of the machinery being measured Note that these machine group classifications are set forth in ISO 10816 3 which rates overall velocity vibration levels for standardized machinery classifications Group 1 and 3 ISO Group 1 and 3 classifications define the following type of machinery Large machinery and electrical machines with a shaft height greater than 315 mm These machines are generally equipped with sleeve bearings but may use rolling element bearings These machines include pumps with multi vane impellers and integrated drivers Group 2 and 4 ISO Group 2 and 4 classifications define the following type of machinery Medium sized machines and electrica
11. 1 and 2 then cannot be used since the used frequency range is identical with the last range on the screen No 6 The diagnostics of the low speed bearing will then be much more successful if we use the lowest range 0 5 16 kHz 38 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio lll FASIT Expert System The description of the FASIT was made in the beginning of his guide This screen can be displayed behind the screen No 6 right arrow or simply from the screen No 1 left arrow because it is before the No 1 For correct evaluation the speed must be defined The instrument can do it automatically or by user manual entry As it has been described in Screen No 1 section the machine condition is divided into 3 levels which have the same colours like traffic lights The same approach we also use for fault detection all 1500 RPM a In the left bottom corner you see the Machine icon The vertical bar displays the overall machine condition This condition can be evocated by many reasons The unit evaluates the severity of 3 sources which are the most occurred in the practise the Unbalance the circle with heavy spot icon the Looseness the shoe icon the Misalignment the clutch icon Correspondent faults horizontal bars are in middle On the right bottom corner you find the rolling bearing icon The vertical bar displays the bearing condit
12. D technology which low power consumption enables to use the stroboscope in our instrument Stroboscope or stroboscopic lamp commonly called a strobe is the device which produces regular flashes of light When we have to study or to visually inspect the machinery which have cyclically moving parts then the stroboscope enables to froze the moving usually rotation Imagine the simplest form a rotating disc with one spaced hole When the flashes of light are synchronized with the rotational speed of the disc then just one flash is made during one rotation It means the disc is lightened up when the hole is always in the same position It is the principle of illusion of frozen movement See the Menu chapter for details 19 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III The Torch You sometimes need to inspect or read the dark corners In that time you are lucky with A4900 Vibrio II because this instrument has built in torch in front panel See the Menu chapter for details 20 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Instrument Operation Switching on and off The instrument is switched on by pressing of the middle button marked with O Instrument on off button Fig Buttons Switching the instrument on Provided that batteries with sufficient v
13. ROR then some item are not available Move between items by pressing V_A buttons Select item by pressing button Use ESC for return from Menu all D LIGHT J STROBO VOLUME 5 Menu selection 4 buttons Fig Instrument MENU MENU Enter escape button gt TROBO T Fig Meaning of the buttons Fig Instrument MENU in error stage LIGHT In LIGHT mode it s possible to use instrument like the torch Select the LIGHT mode and press button White LED built in on the front side begins to light Symbol of the torch appears on display Press any button to switch off the light and the instrument starts to measure again Fig Torch mode 26 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio lll STROBO In STROBO mode you can use the instrument as the stroboscope White LED built in on the front side begins to flash with a frequency which is set up on the screen If the speed determination is known then frequency of flashes is set to that value By pressing WV A buttons you can to also change that frequency manually The step 1 10 100 RPM is displayed on the bottom line of the screen Press the button and the STROBO menu appears You can switch off STOP the stroboscope or change the step frequency tuning Escape STROBO mode Preset frequency 1n RPM and Hz 1500 pew ae 2 5 0 0 Hz _ Prese
14. RPM means revolutions per minute The instrument performs automatic determination of machine revolutions using a spectrum analysis This function does not have to be always successful because the revolutions may not be possible to read for every spectrum If the speed is not determined it is not a malfunction It is hard to do it for example in machines with gears If the speed is available then and vibration values have been coloured corresponding to vibration limits Machine conditions are divided into 3 levels which have the same colours like traffic lights 1 GOOD GREEN COLOUR Machine is in good condition no defect is found The operation is without restrictions 2 ALERT AMBER COLOUR The beginning defect is found on the machine It is possible to operate with paying more attention and planning of repair 32 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III 3 DANGER RED COLOUR There is an serious defect found on the machine Machine shouldn t be in operation Overall PEAK values Similar rules for evaluation of the measured values as in the previous screen are valid for this screen with one difference The peak PEAK vibration values are displayed It is highest measured value in certain time which is important for transient shock events evaluation especially in cases of incipient bearing defects like microscopic peeling off of
15. UT COMPLETELY The pushed out cement may be removed or levelled out around the pad In the end you put a cover on the pad When using the T pad amount of the cement is dependent on the size of the gap between the ribs and it is not so easy to determine amount of the cement to process As with the simple pad the surface between the ribs must be well cleaned and degreased The space shall be filled with the necessary amount of the cement so that only the cylindrical part of the pad remains visible after drying of the cement Beetle in the surrounding cement In the end put a cover on the pad Listening to Vibrations Using Headphones A user can connect headphones to the Adash 4900 Vibrio III instrument since listening to a measurement signal also enables a differentiation of a problem type People can think that this is an old method which does not have a place in this modern world The opposite is true Analyses of gears and low speed bearings e g in paper mills gain better quality by using the listening method The listening can easily be done by any maintenance person without deeper knowledge of diagnostics If there is a defective bearing then distinct rumbling sound is audible in the headphones If the bearing is OK then you can hear only a weak noise HEADPHONES WARNING Listen at moderate volumes to avoid hearing damage Always remove the headphones from the ears when you move the sensor or re connect cable Relationship of Meas
16. ards for special machines e g turbines and these standards are a strong diagnostic tool General standards have a character of recommendation on how to define the limit values The way how to find the good condition values is to use measured values of new or repaired machine Also you can ask the machine producer for them 5 Shortening of an interval between measurements means more successful prevention of unexpected failures 5 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Machine and bearing condition diagnostics Basic defects which we d like to find out are unbalance heavy spot on the rotor causes vibrations misalignment machinery parts are not in alignment looseness machine is not properly connected with its base soft foot bearing defect wear of bearing bad assembly bad lubrication or overload First three defects influence the whole machine e g the vibration caused by unbalance we can take from any point on the machine We use the vibration velocity mm s measurements for that Roller ball bearing condition we can detect only on the nearest point This is the local failure We measure always vibration acceleration only g Methods for ball bearing condition diagnostics We can find out several methods for bearing condition detection in literature We should repeat again we have to measure vibration acceleration in g
17. cessories 10 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Before You Start Ignoring any of the recommendations mentioned below may cause failure of the instrument Handling voltage higher then 24 V can cause an accident 1 Always connect only ICP type of sensor into an ICP marked socket If unsure consult the procedure with your supplier 2 Never plug this instrument into 230 V household voltage 3 To power this instrument use batteries with max nominal voltage of 1 5 V 4 To power this instrument use only alkaline or rechargeable NiCd NiMH batteries Regular carbon zinc batteries are not suitable WARNING Use correct battery polarity Incorrect polarity will cause destruction of the instrument HEADPHONES WARNING Listen at moderate volumes to avoid hearing damage Remove the headphones from the ears when you move the sensor or re connect cable 11 Further technical and contact information can be found at www adashusa com www adash czZ ADASH Ltd Adash 4900 Vibrio III Standards for vibration measurements Standards using is occasional topic in vibration diagnostics Because there are a lot of different types of machines it is impossible to determine the critical limits of vibrations for wide range of machines Its reliability would be low then It would happened the decommissioning and repair machines which do not
18. d to the sensor and then it is magnetically fixed to the metal surface of the machine Hence the sensor is fixed and a measurement is possible Quality of fixation markedly influences the result of your measurement If the sensor swings or jumps about etc your measurement is pointless A layer of paint is also a big obstacle for higher frequencies The magnetic base has ground surface and the same surface quality must be created on the machine In practice it is not possible A flat surface 3x3 cm in size can be ground only in a workshop Anyway quality of the bearing s housing steel is not high and such a surface can quickly succumb to corrosion Then it becomes unusable Solution to this problem is to use measurement pads These are the cylinders with the diameter approx 26 mm and height 10 mm with a ground surface made of a magnetic stainless steel They are fixed to chosen points with special glue which ensures a perfect transmission of the high frequency vibrations The pad is covered with a plastic cover which is removed only for the measurement Another advantage of the cover is that when the machine is painted your measurement point is preserved The paint would devalue the pad It is sufficient to coarsely grind the machine s surface and degrease it before the pad is glued Durability of the pads in time is unlimited In practice it is always until a forcible removal You will need mainly the following aids angle grinder set
19. dets aaa oa able tara Mtat aaa ed seca dea teeta 21 AOMA ONNE iia ounce sedacevane a ted tentugertebenieiadadadanesierreisaaees 22 ISING Ol ICAO MOM CS ecean E E EA aA 22 Selection OF MEASULEIMON wasscacdsswervcrnaert a a a A 23 Measurement Methods SCIreens ccccccceecceeeteeeteeeteeeteeeneeeseesnecsueeeeteeeaeeeeeesseeaneeeaes 23 Speed GELSCLION ANG GSTMITON arraren aa daar aiesnidar aud Peh oaadiadvd omens 25 Menu TOF functions Selecion A 26 BE a EAE E TEA P E AT E AP P N ANA ES AE A E E O E T 26 SIROB O aa aaa a a aa a a ae 27 INE aaa a a a a a a nants 27 SETUP a A A A Aoatecaatoaae 28 SPEED ea E E A E E A aa 28 ALARM S A E E A N TEA EE eae ee a eee 28 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III CIN S aa meskes E A at diab Naat be ah dag ana ne capone catia AAA 29 Bl E ea ee E E A A E A ose net ee ee ee een eee ae 29 ION Message S a sacnen vend seu seerc uct E E E 30 SENSOF COMMNECIION ENO anaona a a a 30 OV SO ACE OU arana E A a a aa iat 30 Measurement EMON js arcs5 aiiawasttedart Ohman D aan eGuide ie aaadeuaaitdadaeeh aly A 31 How to evaluate the failure annnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn nnmnnn nnmnnn nnnm nmn 32 Overall RMS VIIC S onain a a a a 32 Overall PEAK VAIE Sissis T E 33 Spectrum 200 HZ Detection of LOOSENESS ineei 33 Time signal for bearing condition evaluation ccc eccceeccce
20. e defined See Standards for vibration measurements chapter 28 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Chosen standard is displayed above the machine symbol F13 in this case If Adash standard is chosen nothing is displayed till ALTO 4800 RPM UNITS Vibration speed unit can be chosen here mm s millimeters per second and ips inch per second are available Device remembers chosen unit even after switch off ESC Return to the MENU screen 29 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Error Messages Sensor connection Error 1 This error signifies incorrect connection of a sensor unsuitable sensor type broken cable etc Overload Error If an input signal is too strong higher than 12V peak and the instrument cannot process it the overload error is displayed The instrument is not capable of measuring this signal 30 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Measurement Error If there is a break in communication between measuring and display boards inside of the instrument this measurement initialisation error is displayed MEAS INIT If you see this error it means that the instrument is malfunctioning and we recommend to se
21. e measuring tip only in hard to reach places where it is not possible to place the magnetic base Automatic determination of the machine speed It s important to know the speed for evaluation of the machine condition Instrument is looking for speed in the frequency spectrum 200Hz range It is assumed that most of the vibration energy is located on the speed frequency If the instrument finds significant energy level on one frequency that means in very narrow band then this frequency is labelled as the speed frequency From this description is clear that the speed has not to be found always If the higher level of energy is located in the spectrum on other line then speed frequency for example frequency of the fan blades then the wrong result can be displayed But the correct speed which must be defined for condition levels can be also entered manually Evaluation of the machine and bearing conditions Diagnostician is always asking a basic question after measurement What condition of the machine should assign to this measured value Machine conditions are divided into 3 levels which have the same colours like traffic lights 1 GOOD GREEN COLOUR Machine is in good condition no defect is found The operation is without restrictions 2 ALERT AMBER COLOUR The beginning defect is found on the machine It is possible to operate with paying more attention and planning of repair 3 DANGER RED COLOUR There is a serious def
22. eceeeeeceeeeeeeeseeeseueeseeeseueeseeesaees 34 Vibrations on frequency range gearboxes bearingsS ccccccceecceececeeeeeeeeseeceseeeeeeesaees 36 PASI EXPE SY SIC a renia lated cade Pe Saad tua dnch a a tide baal ataG aaah 39 Specifications Adash 4900 Vibrio Ill cc ceeceeseeeseesseeescenseeeeeenseeseoeeseeeseenneessoseeessoeees 40 3 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Why perform vibration diagnostics A4900 Vibrio III instrument is able to do all required basic vibration diagnostic measurements That means bearing condition lubrication mechanical faults misalignment unbalance mechanical looseness and resonance The instrument performs a lot of operations automatically It s possible to connect ear phones to listen vibration signal which is very useful for gearbox and slow running roller bearing diagnosis The instrument is able to measure machine vibration very precisely to determine condition its source and level of damage The instrument is designed to be a standard technicians and maintenance staff equipment Vibration diagnostic allows checking the condition of all your machinery You will be informed early about potential failure before the machine get damage and you will be able to order only real specific required maintenance instead of expensive overhauls The periodical measurements will allow you to keep y
23. ect found on the machine Machine shouldn t be in operation 18 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Special functions are included in the instrument for the determination of that three states The overall vibration values are colored with appropriate color The vibration limits Adash for each state are determined from the graphs which are printed in the Adash Limit Values of Machine and Bearing Vibrations chapter Fasit Expert System Press the left arrow on the screen No 1 and the FASIT screen appears For correct evaluation the speed must be defined The instrument can do it automatically or by user manual entry antl 1500 RPM re In the left bottom corner you see the Machine icon The vertical bar displays the general overall machine condition This condition can be evocated by many reasons The unit evaluates the severity of 3 sources which are the most occurred in the practise the Unbalance the circle with heavy spot icon the Looseness the shoe icon the Misalignment the clutch icon Correspondent faults horizontal bars are in middle On the right bottom corner you find the rolling bearing icon The vertical bar displays the bearing condition The Stroboscope The build in stroboscope inside the A4900 Vibrio III represents the unique innovation in the handheld vibration analyzer field We use the high lighting LE
24. er or shaft height cccceceeeeeees 14 Classification according tO foundation cccceeccccceeeeeeceeeeeeeaeeeeeecaeeeesseeeeeeeeeeseaeeeesaaeeeesaaeeees 14 Evaluation Tanges nosice oa Dd ysianataaes acm a ade daabidedtnalit a i a 14 Classification of vibration values for machines groups 1 and 3 cece ceeecceceeeeeeeeeeeeeeaeeeeeeaeeees 15 Classification of vibration values for machines groups 2 and 4 nnnnsnnnensnnnsnnnensnrnnsnrnrsrnrennne 15 Values setting in A4900 Vibrio II Unit cece cecceeeeeeeteeeteeeteeeeeeeeeeeeeeeeeetaeeteeeaeenaes 15 QWCK Sta nae ENE T 16 Preparation of Measurement POINt ccccccceccceeceseceseeeeeceeeeeeeeeeeteeecaeeeseeeneeeeeeseeteeetaess 16 Puting IN AMC TIO x scescpatshis Gates thers ecole a fda teace tens 16 Plugging Im Vibration Sensor eisirean a Oa ar a 17 COnN COT a E I E E dacataeaatands 18 WIS UII Ocan E ecletedee eek eect ect asec etn eeeetaes 18 Automatic determination of the machine SPEE ccccecccsccceeceseceeeeseeeeeetseeteeeteeeeeeeaaes 18 Evaluation of the machine and bearing conditions cece ceccceececeeeceeeeeeeseeeseeeeseeeteneees 18 FaSt EX DEM SYSE icnevenerndsecxsensar dant E ES 19 TAE SUODOS CODES cesses seein dec voce E A A A eaieandes 19 TME ONG apostate hia Sete ee rebate a a dnase mses ates Gaetee en eee 20 instrument ODN ALI ON aroni anna aaa a du saun aaa ealonsawaledeasineaaat 21 SVWITCIMIMO ON QING OM scepter ca
25. ion The meaning of Machine and Bearing bars was described in Screen No 1 What do the colours mean in faults bars GREEN COLOUR It may surprise somebody because why to think about faults when the colour is green But also from low level signal the procedure can read the beginning of the fault But the operation is without restrictions AMBER COLOUR The beginning level of defect is found on the machine It is possible to operate with paying more attention and planning of repair RED COLOUR There is the serious defect level found on the machine Machine shouldn t be in operation 39 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III specifications Adash 4900 Vibrio lll Input Measurements 1x ICP powered accelerometer 100 mV g sensitivity RMS PEAK 10 Hz 1000 Hz mm s um mm Spectrum 200 Hz mm s Display Range Further functions Output Power Dimensions Weight Accessories RMS PEAK 500 Hz 16000 Hz g RMS PEAK 1500 Hz 16000 Hz g RMS PEAK 5000 Hz 16000 Hz g Time signal 500 Hz 16000 Hz g color OLED display 128 x 128 pixels diagonal 1 5 38mm max 80g PEAK LED stroboscope 0 17 Hz 300 Hz 10 RPM 18000 RPM LED torch 1x AC signal 8 Q 0 5 W for external headphones signal listening 2x1 5V AA size alkaline batteries or 2x1 2V NIMH AA s
26. ithout corrosion and paint It should also be flat so a sensor would not wobble The best is to use a measurement base which is glued on a machine It has a perfect finish plastic cover and is made from magnetic stainless steel This will enable you to perform the measurements on the machine at any time under the same conditions This measurement repeatability means that you will be able to compare the values well To attach the sensor use a magnetic sensor base do not forget to remove a magnet cover from it which closes a magnetic field and protects the magnet from long term weakening in storage Putting in Batteries Batteries are accessible after opening a lid at a bottom part of the instrument Open the lid by pressing its lower edge the edge with hinge the lid upper part opens easily see figure Do not ever use force Proper polarity is shown on the picture Do not forget to switch the instrument off before opening the power battery lid Never handle the power batteries with the instrument switched on i 1 Press gently Fig Opening of the lid 16 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Fig Placement of power batteries Fig Proper cell polarity Plugging in Vibration Sensor To measure a vibration signal we need to plug in the vibration sensor with ICP power The plugged in sensor must be a standard accelerometer with 100 mV
27. ize rechargeable batteries 150 x 60 x 35 mm 350 g including batteries without cable sensor and magnet 540 g including batteries cable sensor and magnet vibration sensor coiled cable to connect vibration sensor magnetic clamp for vibration sensor headphones recording cable with 3 5 mm jacks measuring tip for manual pressure on the sensor 1 5V alkaline batteries transport case 40 Further technical and contact information can be found at www adashusa com www adash cz
28. l machines with a shaft height between 160 and 315 mm These machines are normally equipped with rolling element bearings but may use sleeve bearings and operate at speeds above 600 RPM These machines include pumps with multi vane impellers and integrated drivers Classification according to foundation An additional setting allows the specification when defining the overall alarm levels of measurements taken from machinery with Rigid or Flexible foundations Evaluation ranges For evaluation of the machine health from vibrations there are defined following evaluation ranges Range A New machine vibrations should occasionally be in this range Range B Machines in this range can be operated for unlimited period Range C Machines in this range are not acceptable for a long period operation they could be operated till the repair time only Range D Vibration values in this range are considered as very dangerous an they can cause a damage of the machine 14 Further technical and contact information can be found at www adashusa com www adash czZ ADASH Ltd Adash 4900 Vibrio III Classification of vibration values for machines groups 1 and 3 Foundation class RMS velocity values border zone mm s Rigid R13 2 3 A B 4 5 B C 7 1 C D Flexible F13 3 5 A B 7 1 B C 11 0 C D Classification of vibration values for machines groups 2 and 4 Foundation class RMS velocity values border zone mm s Rigid R24 1 4 A B 2 8 B C
29. nd it to the manufacturer for a check 31 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III How to evaluate the failure The instrument shows measurement results on several separate screens We shall describe basic rules for their use Overall RMS values 1140 RPM Machine symbol this line shows a RMS velocity vibration value in mm s or ips which is excited on the machine by mechanical phenomena related to imbalance of rotational parts of the machine fan wheel impeller clutch wheel etc incorrect axis alignment of the assembly misalignment mechanical looseness of individual machine parts large free play in seating of rotational machine parts shaft bearing shaft bearing housing clutch free play e g free play on a shaft pressed out grooves and tongues loose or worn out machine anchor bolts defective base insufficient frame or anchoring flange rigidity damage to machine rotation parts bent shaft Bearing symbol this line shows a RMS acceleration vibration value on g which is excited by a condition of bearing This condition is related to time wear of the bearing bad lubrication with new bearings as well incorrect installation with new bearings as well abrading of bearing SPEED The machine speed is displayed at the bottom part of the screen if it is available
30. ng of headphones and listening to a measured signal We can connect the headphones by a stereo 3 5 mm jack marked phones on the top of the instrument see figure in the Connectors chapter After connecting we can hear a signal from the vibration sensor in the headphones Advisable volume can be set up by the VOLUME item from the instrument menu see MENU chapter Decrease volume i Increase volume button f button Switch measuring volume control button Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Selection of Measurement A selection of measuring screen method can be performed by the buttons A After press of a button an empty screen is shown without measured data and the measuring starts Measuring screen selection buttons Fig Measuring screen selection buttons Measurement Methods Screens 1140 RPM Overall RMS values Measurement of RMS vibration values in the ranges 10 Hz 1000 Hz in mm s 5 kHz 16 kHz in g with estimated value of machine speed frequency Based on the speed and vibration values the machine condition and a colour of the displayed value green amber red is determined Overall PEAK values Measurement of peak vibration values in the ranges 10 Hz 1000 Hz in mm s 5 kHz 16 kHz in g 23 Further technical and contact information can be found at www adashusa com www adash cz
31. nges Condition 2 Vibrations are concentrated in the last frequency range 5 16 kHz the vibrations in the last area are the same as in the area where the tooth frequency shows itself bearing failure 3 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Condition 3 While in the last band the vibration value is very low in the first two frequency bands the values are very high Very high probability of gear defect wear of teeth change of bite angle as a consequence of wrong correction wrong mutual axis distance of drive and driven shafts misalignment of drive and driven shafts All these phenomena increase vibrations in the tooth frequency Condition 4 The last screen shows a case when the vibration may not be excited by a bearing or a gear Very often these are vibrations of the equipment tied to the mentioned machine In case of multiple geared transmissions however these can be also the tooth frequencies of the second or third transmission gear Here we would not be able to do without a detailed analysis using an instrument with possibility of the spectrum analysis measurement The measurements on the screen No 6 can also be used in diagnostics of condition of low speed rolling bearings They usually have larger sizes and when bearing defects occur the vibrations are radiated in the lower frequency ranges The screens
32. of files emery paper degreaser ethanol solvent measurement pads and glue Prepare the surface in the following way remove the paint corrosion or unevenness from the surface by grinding degrease the surface The pad is being fixed on measurement point with the glue We usually use the METAL TECH SG cement also other glues with similar properties may be used EE TTE sang far elar AE ADRAD ran a Akie Bala ae e E The METAL TECH SG cement is a 2 component epoxy cement with properties best suited for this task The two components after mechanical mixing chemically react and after drying they form a hard material resistant to pressure temperature and humidity In the case of the simple pad the procedure is as follows cut off a disc approx 3 mm thick from the cement with a sharp knife Wet your fingers and work the disc into a homogenous lump Roll a cylinder with the diameter approx 2 3 mm from this lump and put it on the side which is not roughened Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Push the pad with glue to the prepared place and while constantly pushing and turning the pad there and back with circular movements observe that the cement is being evenly pushed out along the circumference of the pad The purpose is to make the layer between the pad and the surface as thin as possible ATTENTION CEMENT MUST NOT BE PUSHED O
33. oltage are placed in the instrument then a display will show an instrument Logo If the batteries are weak the VIBRIO sign is bordered in red Fig Switching on with Fig Switching on with Fig Switching off weak batteries The instrument is switched off by pressing and holding the same button O fora longer time Before the instrument switches of the sign POWER OFF lights on the display slowly goes out and the instrument switches off if you release the button 21 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Information line After powering on the display shows measured data Beyond descriptions of the measured values and their actual values the display shows an information line in its upper part Fig Information line on a display Meaning of Displayed Symbols moving wave signifies measurement in progress Pe setting of headphone output volume is indicated by yellow colouring of the bars LS this symbols shows an approximate battery status The more is the symbol filled in the more battery power remains If the status goes under 20 the remaining energy shows in red if it is insufficient the symbol is red and the instrument switches itself off Battery status symbol J i J J 100 approx 50 under 20 just before switching off Using of Headphones The instrument is equipped by a 0 5 W amplifier for connecti
34. ostics solves two basic tasks 1 Diagnostics of machine mechanical failure imbalance misalignment mechanical loosenes etc 2 Diagnostics of rolling bearing condition Basic Rules 1 If the measured value of vibration increases in time it is a change indicator worsening of the machine condition 2 If the measured values do not change the machine works in stable operation condition This does not necessarily mean that this state is good For example if a bearing was installed incorrectly then there would be a high signal value immediately This value will remain stable for some time the bearing will be able to withstand it but then there will be a fast increase and destruction of the bearing This short bearing life can take hours days weeks or even months 3 Reliability of the diagnostics will never be 100 There will always be defects which develop in time shorter than regular measurements The defects that are caused by material fatigue can develop in several seconds only cracks breaks The proof of the diagnostic performance is primarily a decrease in maintenance costs not to absolute zero and a significant decrease in unexpected breakdowns not their complete elimination 4 Using of standards is possible only with special machines for which the special standards exist It is not possible to simply define limit vibration values in general for a wide range of machines However it is possible to create the stand
35. our machines in good health You always ask before the decision to buy new instruments what unit is the best for your needs Is it a instrument with a large amount of functions including specialized software for data processing which you will not ever use or is it an instrument which is easier to use and contains all required functions You should pay only for functions which you will use in the field The A4900 Vibrio III is just that instrument The instrument uses standard external accelerometer with the magnetic base It enables correct repeatable measurements You should not equate our unit with vibration pens 4 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Vibration Diagnostics Basic Information Introduction What is it the vibration diagnostics This chapter explains the basic steps and you will be able to begin practical measurements More information you can find in the literature If we are talking about the vibration diagnostics we mean regular measurements usually every 2 4 weeks whose objectives primarily are 1 Finding of change of vibration level it means change of machine operational condition 2 Determining reason for this change 3 Recommending maintenance repair adjustment lubrication etc 4 Checking of maintenance success including revision of dismantled part to confirm the analysis The machine vibration diagn
36. require it On the other hand there would be unacceptable breakdowns because measured values could be high but not exceeded the limit The standards should be determined for a narrow range of machines A4900 Vibrio III contains Adash limit values They are not rewritten from any existing standards It s a result of 20 years of Adash engineering team experiences It s difficult to invent critical value definition which would be simple that means not many parameters such as speed power bearing type machine type and so on and reliable On the figures below is clear how we derived limit values Three levels of machine condition are defined GOOD ALERT Machines lays in this range are not acceptable for a long period operation they could be operated till time when could be repaired and DANGER Vibration values in this range are considered as very dangerous an they can cause a damage of the machine The corresponding colors are taken from traffic semaphore green amber and red GOOD state is the space up to the yellow line that means operation without restriction The space above yellow but under red line is an ALERT state Possible to operate the machine but have to be more checked It s necessary to determine the source of worse condition and plan repair for instance change the bearing or maintenance balancing alignment The space above red line is an DANGER state and the machine should not be operated First figure contains the values
37. sadvantages like the PEAK measurement The relation between gears and ball bearings For gearboxes diagnose it is also necessary to measure acceleration signal like for ball bearings When the balls are rolling over the damage tracks pitting the shock pulses occur in signal Unfortunately similar shocks are also in signal from on worn or damaged gears So if we measure gearbox with roller bearings then higher vibration values can be caused by both sources More information for this kind of analysis you can find in chapter Vibrations in frequency range gearboxes bearings 6 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III FASIT Fault Source Identification Tool The FASIT is also included in the Adash 4900 Vibrio III The name FASIT is used in more Adash products for expert system which would help the user to find the source of vibration troubles It is good message for users because such functions were not ever built in the instrument in this price category The FASIT displays several bar graphs with traffic light colours Two major largest bars are allocated to general machine condition on the left side and ball bearing condition on the right side 1500 RPM re The next three bars are located in the middle They displays the severity level of UNBALANCE LOOSENES and MISALIGNMENT from the top Measurement Points The measurement location mus
38. t enable repeatable measurements under the same conditions as the previous measurement Also the direction of sensor radial axial for rotated machines is important That is why you we should determine measurement points on the machine The typical machine together with the measurement points in the picture MP 29 MP1 FAN For the measurement in radial direction we are going to place the sensor perpendicularly to the axis of rotation for axial measurement along the axis The radial measurement can usually be performed horizontally vertically or in another angle The importance of the angle choice should not be overstressed choose any radial direction with easy access The measurement points need to be prepared for the measurements The best is to place measuring pads on a machine see the chapter Preparation of Measuring Location 7 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio lll The preparation of the measurement point On the measurement point we make a measurement To obtain a quality measurement the points for measurements must be prepared in advance For regular measurements the sensor must be always fixed in the same way at the same point For diagnostics of bearings it is necessary to fix the sensor with a magnetic base Do not push the sensor only by hand high frequencies cannot be measured in this way The magnetic base is firmly screwe
39. t gt atl mm s RMS Push arrows it changes the value of speed with the step 250 RPM When the correct speed or the value near the correct speed is defined push Enter button for confirmation If no pushbutton is used for approx 4 seconds then the displayed value is accepted The word lt set gt is changed to MAN then This word informs all the time the user that speed is entered manually When you need to set exact value and the 250 RPM step is too much then use the STROBO item from the MENU atl mmr S Rho If the automatic detection is switch on this procedure of speed determination runs always when the screen No 1 appears When it is switch off the immediately the lt set gt message appears 25 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Menu for functions selection By pressing button the instrument menu appears If the instrument is in the error stage for example SENSOR ERROR then some functions are not available LIGHT Torch mode STROBO Stroboscope mode VOLUME Phone output volume adjustment SETUP This item opens next item selection SPEED Automatic speed detection ON or OFF ALARMS Selection of standard which will define limit values UNIT Unit options for a measuring of a velocity signal mm s vs ips ESC Return to the measuring screen If the error is detected e g SENSOR ER
40. t step Y A lo gt mae step p increasing 100 RPM 42 y RPM decreasing AFi Fig STROBO mode Fig STROBO mode menu VOLUME The volume bars appear The volume is changed by buttons A When the maximum volume is reached the symbol will become orange otherwise the amount of yellow filling shows the actual volume If the headphones are off the symbol is grey Next press of the button returns the instrument back to the measurement mode till Switched off till Maximum Fig Volume adjustment Fig Displayed volume During the instrument is switched on or off the range is changed the sensor is connected or disconnected the short unpleasant crack can be heard This is not a defect of the instrument Be careful not to overload the headphone amplifier by excessive volume This will distort a signal in the headphones You can use any stereo or mono headphones with nominal impedance higher than 8 Q Both output stereo channels are connected to the signal 27 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III SETUP Further functions menu appeared ALARMS UNITS Choose requested function using arrows and confirm by Enter SPEED Switch on ON or switch off OFF automatic determination of revolutions function AUTO OFF ALARMS Standards setup Alert limits amber color and Danger red color will b
41. uring in Acceleration and Speed Maintenance staffs usually use to measure often only vibrations in mm s or inch s velocity and not vibrations in g 9 81 m s acceleration This is a relic of the past when old equipment enabled the vibration speed measurement only Bearing defects are not recognisable by using velocity measurements If the velocity value increases due to a bearing defect then the defect is already serious and there is an acute danger of unexpected breakdown The measuring of the velocity vibration does not give early enough warning before failure of a rolling bearing For accurate bearing condition measurement you have to measure the acceleration vibration Abbreviations used in the guide Abbreviations below are used in the User s guide RPM Revolutions per minute CPS Revolutions per second RMS RMS value of the measured signal PEAK Peak value of the measured signal 9 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio lll What Will You Get with Your Instrument Instrument and accessories The instrument case contains measuring instrument A4900 Vibrio III vibration sensor accelerometer magnetic base for vibration sensor coiled cable to connect vibration sensor headphones measuring tip for putting manual pressure on vibration sensor 1 5V alkaline batteries Fig Adash 4900 Vibrio III with ac
42. used by a rolling element coming across the damage like pitting or crack here The shocks repeat themselves regularly g EM 0 33 The range of the graph is different again 2 0 g in this case 35 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio III Vibrations on frequency range gearboxes bearings When we need to find the failure on not simple machines e g gearbox then is very usefull to know the vibration values in several frequency bands The screen No 6 shows measurement values in three frequency bands 0 5 16kHz the whole vibration area occurring in transmissions due to friction in bearings bite of gears abrasion of limiting rings etc beyond low frequency phenomena the imbalance etc which we measure using the first four screens 1 5 16kHz in the area from 1 5 kHz we can find driving wheel gear frequencies of most transmissions 5 kHz 16 kHz this range is typical for bearing defects where the high frequency signal occurs as a consequence of bad lubrication abrasion bearing wear or overload Attention Please note that the ranges overlap They all have the upper frequency 16 kHz What does it mean for analysis The following examples should help you to understand their significance All values are the same All vibrations are in the last range If they were in the lower ranges also the highest range would have to ha
43. ve a lower value In the first two ranges the value is the same the last range value is lower The vibrations are in the range 1 5 5 KHz They are not above 5 kHz this would express itself in the last range They are not under 1 5 kHz the value in the first range would have to be higher than in the second one The first range has the highest value The vibrations are in the range 0 5 1 5 kHz The reasoning is the same as in the previous example The value in the higher range is larger than in the lower one This must be a measurement error It is logically impossible to have a higher value in the last range than in the middle one The reason is their overlapping 36 Further technical and contact information can be found at www adashusa com www adash cz ADASH Ltd Adash 4900 Vibrio lll Example We are going to show the analysis procedure on a signal obtained on a seating of an inlet transmission shaft with the speed frequency 25 Hz 1500 rpm and with a gear with 65 teeth So called tooth frequency can be obtained by simple multiplication of the shaft revolution frequency in Hz by the number of teeth fome fspeed Le feme gear mesh frequency fspeed speed frequency Z number of teeth In our example the tooth frequency is 1625 Hz so approx 1 6 kHz What are the possibilities Condition 1 The transmission is OK and tooth frequency of 1 6 kHz slightly increases vibrations in the first two frequency ra
Download Pdf Manuals
Related Search