Adash 4900 – Vibrio III fflfflfflffl User's Guide
Contents
1. 6 0 0 24 5 0 0 2 A A D 4 0 0 16 T o co 2 jia 30 0 12 m L r O O O O T d 2 0 0 08 2 y 1 0 0 04 0 0 0 0 500 1000 1500 2000 2500 3000 3500 4000 speed RPM gt 3 5 3 0 gt Pa O M Acc 5k 16kHz g RMS gt in ad O 0 0 0 1000 2000 3000 4000 5000 6000 7000 8000 speed RPM gt 14 Further technical and contact information can be found at www adash eu 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 Vibrio III 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 industrial machines with normal power above 15kW and nominal speeds between 120 r min and 15000 r min when measured in situ ISO Groups 1 4 classifications define the following types of machinery Group 1 Large machines rated power above 300kW with a shaft height greater than 315 mm These machines are norm2. Overall RMS values AUTO 4800 RPM re Machine symbol this line shows 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 RMS acceleration vibration value in 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 The thermometer symbol is drawn together with the bearing The temperature color is used according the actual measured value SPEED The machine speed is displayed at the bottom part of the screen if it is available RPM means revolutions per minute The instrument performs automatic detection of machine revolutions using a spectrum analysis This function does not have to be always successful because the revolutions ma
3. 3 HP filter frequency for bearing in kHz 0 5 kHz The instrument is switched off by pressing and holding the same button fora longer time The POWER OFF appears on the display Release the button and the instrument switches off Stand by mode When the user does not press any button for 10 minutes the instrument changes the standard run mode to the Stand by mode the screen is darkened When the user does not operate with the instrument next 30 minutes the instrument switches off 23 Further technical and contact information can be found at www adash eu 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 Pe setting of earphone output volume is indicated by yellow coloring of the bars LS this symbol shows an approximate battery status If the battery symbol is filled more then 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 moving wave signifies measurement in progress Battery status symbol d i J J 100 approx 50 under 20 just before switching off Using of earphones The instrument is equipped by a 0 5 W amplifier fo
4. 7 1 0 28 B C 11 0 0 43 C D Classification of vibration values for machines groups 2 and 4 Foundation class RMS velocity values border zone mm s in s Rigid R24 1 4 0 06 A B 2 8 0 11 B C 4 9 0 18 C D Flexible F24 2 3 0 09 A B 4 5 0 18 B C 7 1 0 28 C D Values setting in A4900 Vibrio lll unit Its possible to set up these values directly in the unit Then the measured values are displayed in traffic light colours You can choose Adash limits recommended or 10 816 limits Setting up is in menu under the mode SETUP see instrument operation Coloured marks according to 10 816 are ranges A and B displayed by green colour 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 16 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Quick Start The aim of this chapter is to introduce you this instrument and without reading a complete User s Guide enable you to measure first vibration values This chapter does not describe full and detailed 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
5. E e E E S T E T A S E TS A EN E T E S ee 33 Eror INICSSAQ CS ennen a S 34 SEMSOM COMME CHO EO aeea a S 34 Display Value Overload ccccccccssseeccecceeeceeecaeeeeceeeseeaeceeeeseaseeeeesseuseceeeeeeaseeeesseaaeeeesssaageeeeeenas 34 MPU OVENO AG ENON etapei aoaaa oraaa e eaea a onae aio Tiagi 34 MEASUPEMENT EMOP sssicerscatsscesdindsncncdasadardatecenansiie aa aa a araa a a 35 How 10 evaluate th Tall cacen iis 36 Overall RMS Vale S reena a T T T T 36 Overall PEAK Vale Seinn na e a a a A 37 Spectrum 200 Hz Detection of LOOSENESS asa E E 37 Time signal for bearing condition evaluation cece cece eecceceeeeceeeeeeceeeaeeceeeaeeseeeseeseeeaeeees 38 Vibrations in frequency bands gearboxes DearingS cscccseccceeeseeeseeeneeeseeeseeeseeeneeenes 40 Fault Source Identification ANd Diagnostics ccccccceececeeceeeecteneeceeeeaeeeceeeeseeeteneeseeeeaes 41 Adash 4900 Vibrio Ill Specifications sss icct cies deve ssscecet hander sdessdetsanetanwnssnccan dent ecnstenedonsdteoees 42 Response Specificato senasis aA 43 Vibration velocity measurement frequency response cccccseccceeeseeeseeeseeeseeeseeeseeeneeenes 43 Vibration acceleration measurement frequency FESPONSE ceccseeeseeeeeeeneeeneeeneeeneeenes 43 Velocity measurement amplitude rTESPONSE ccccseccceeeeseeeseeeeceeeeeeeseeeeeeeeseeeeseeesaeeess 43 Acceleration measurement amplitude reSPONSE cccceceeeeneceeeee
6. by button and your value settings will be saved ESC Returns to the measurement screen 33 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Error Messages Sensor connection Error When incorrect connection of a sensor unsuitable sensor type broken cable etc is detected then the temperature screen occurs and the error message is written upon the values Display Value Overload 49 93 I RPM OFF When the value exceeds the range of display then OVR is displayed Input Overload Error If an input signal is too strong higher than 12V peak the instrument cannot process it the overload error is displayed The instrument is not capable of measuring this signal 34 Further technical and contact information can be found at www adash eu 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 initialization error is displayed MEAS INIT If you see this error it means that the instrument is malfunctioning and we recommend to send it to the manufacturer for repair 35 Further technical and contact information can be found at www adash eu 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
7. 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 1500 RPM Q 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 severity of 3 sources which are the most occurred in the practice Unbalance circle with heavy spot icon Looseness shoe icon Misalignment 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 meaning of Machine and Bearing bars was described in Screen No 1 The temperature bar is displayed quite on right side The ranges of colours are for less than 30 green 30 45 yellow 45 60 orange 60 75 red and for greater than 75 dark red What do the colours means in fault bars of machine and bearing GREEN COLOR lt 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 COLOR The beginning level of defect is found on the machine It is possibl
8. 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 phones input ADASH 4900 Vibrio Fig The instrument with a sensor connected 18 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Connectors top panel The earphones output is on the left 3 5mm jack The accelerometer input is on the right side The contact less temperature sensor is on the bottom Four LEDs of strobo are in the top of panel Vibration Measurements 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 valu
9. it an 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 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 The Adash model A4900 is a multi function portable meter that bridges the gap between the basic and advanced FFT data collector analyser It is a complete machine condition expert system than gives results without the use of a computer or lap top It is designed for the technician engineer and consultant who need to analyse a rotating machine on site without investing and carrying expensive instruments to site This single meter undertakes overall vibration measurement three band spectrum 200lines spectrum Time Wave Form temperature tacho for speed strobe scope In addition it incorporates a handy inspection torch The A4900 caters to ISO 10816 3 with expert rules covering machine health vibration levels that identify the prime machinery faults Unbalance Looseness and Alignment An anti friction bearing health level indication is also incorporated Many informative screens are available Do your machines work under optimum conditions The A4900 will De
10. mode VOLUME Phone output volume adjustment SETUP This item opens next item selection SPEED Set of speed detection 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 ERROR 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 Menu selection S buttons sTROBO es VOLUME Fig Instrument MENU MENU Enter escape button S5 TROBO T Fig Meaning of the buttons Fig Instrument MENU in error stage LIGHT In LIGHT mode it s possible to use instrument like a torch Select the LIGHT mode and press button White LEDs on the front side begins to light Symbol of a torch appears on display Press any button to switch off the light and the instrument starts to measure again Fig Torch mode 29 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III STROBO In STROBO mode you can use the instrument as a stroboscope White LEDs on the front side begins to flash with a frequency which is set up on the screen If the speed detection is known then frequency of flashes is set to that value By pressing W A buttons you can also change that frequency manually The step 1 10 100 RPM is displayed on t
11. problems not related to mechanical looseness bent shaft See also FASIT chapters Time signal for bearing condition evaluation e SITS Ce 0 82 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 atl 0 5 UA 0 16 This bearing generates a low amplitude noise only whose time record shape is steady Its 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 38 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Undamaged bearing wrong lubrication nilll q 1 0 1 0 g EM 0 59 The time record shape is steady too but it has bigger amplitude then previous case You can clearly see different bigger range of the graph 1 0 g Damaged bearing alll g EM 0 33 There are clearly visible shocks caused by a rolling element coming across the damage like pitting or crack here The shocks repeat themselves regularly The range of the graph is different again 2 0 g in this case 39 Further technical and contact information can be found at
12. procedure is displayed as running bar in the bottom of screen The result is also displayed on the bottom When the automatic speed detection is not successful see Automatic detection of the machine rotation chapter the last speed value is loaded from the memory and displayed together with the message lt set gt ll Cset gt 1500 RPM 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 10 4 0 49 MAN 1500 RPM IREM OFF RPM set manually RPM detection switched off If the automatic detection is switch on this procedure of speed detection runs always when the Screen No 1 appears RPM OFF is displayed when the RPM detection Is switched off 28 Further technical and contact information can be found at www adash eu 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
13. 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 of files sand 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 i Dekanati a tai porn roe aiid rity PERREN Pr ry a Meek A anth ee ernie baat eee eer 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 can be found at www adash eu 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 t
14. www adash eu ADASH Ltd Adash 4900 Vibrio III Vibrations in frequency bands gearboxes bearings When we need to find the failure on not simple machines e g gearbox then it is very useful to know the vibration values in several frequency bands The screen No 6 shows measurement acceleration values in three frequency bands 0 5 1 5 kHz 1 5 5 kHz and 5 kHz 16 kHz 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 fame fspeed Z 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 The transmission is OK and tooth frequency of 1 6 kHz slightly increases vibrations in the second frequency band Bearing failure vibrations are concentrated in the last frequency range 5 16 kHz 40 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Fault Source Identification and Diagnostics Description of FASIT has been described in the beginning of this guide This screen can be displayed behind the screen No 6 right arrow or simply from the screen No 1 left arrow For
15. ENV should display 1 33g 2 5 45 Further technical and contact information can be found at www adash eu
16. RNING Listen at moderate volumes to avoid hearing damage Always remove the earphones from the ears when you move the sensor or re connect cable Relationship of Measuring in Acceleration and Speed Maintenance staff usually measure vibrations in mm s or inch s velocity only 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 recognizable 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 10 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III 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 earphon
17. User s Guide YRUUY VEUURYRUVUYRFUVUYRYUYYA Adash 4900 Vibrio Ill Machine vibration diagnostics Bearing diagnostics Lubrication diagnostics Service activities Product Inspection Wideband RMS or PEAK measurements of acceleration velocity and displacement Velocity measurement from 10Hz optionally from 1 Hz for low speed machines Time signals measurement Spectrum FFT analysis Measurement in frequency bands for bearing diagnostics Headphones for listening of vibration Built in ISO 10816 limits Fault Source Identification and Diagnostics Tool Built in Infrared Thermometer Built in stroboscope lamp Detection of machine and bearing conditions Machine speed detection Colour display External piezoelectric accelerometer with 100 mV g sensitivity Overload indicator sensor fault and cable fault indicators Built in torch Simple control by three buttons Ref No 0201 _ 2012 ADASH Ltd Adash 4900 Vibrio III Contents Why perform vibration GiaQnOStiCs cccccceeseeseeeeeeeeeeneeeeeeenssenseeaseeaeeoneeeaeeeaeeeaeeeaeeeneenaes 4 WIV A4900 VIDO WM oria a 5 Vibration Diagnostics Basic INfOrMatiONn cccceeseeeseeeseeeeeeeseenseenseenseenseeneeeaeeeneeoneenaes 6 Hak geye 6 Xo g eemmeeessme eens mine eeatieeten rn ena Ne Meee rrr Sie nS cre TO en are Oe oe ee oe 6 BaSe RUD c eee ae ae einen eC Ee ee Sk RO Ble nee eae einen Mane eee eee ae en ene enc ae eee Nee 6 Machine and bearing c
18. Values of Machine and Bearing Vibrations chapter Fault Source Identification and Diagnostics Tool Press the left arrow on the screen No 1 and the Fault Source Identification and Diagnostics screen appears For correct evaluation the speed must be defined The instrument can do it automatically or by user manual entry 20 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III PAO REM e 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 practice Unbalance circle with heavy spot icon Looseness shoe icon Misalignment 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 IIl represents the unique innovation in the handheld vibration analyzer field We use the high lighting LED 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 stro
19. a a e 15 Classification according to machine type nominal power or shaft height cccceeceeseeeeees 15 ISO Groups 1 4 classifications define the following types Of MACHINETY cccceeeceeeeeeeeeees 15 Classification according to fOUNGALION veiihete cahcdeetecdsevivedi Abel onst euros ite 15 EVAlUAOM ANGSSiiccnsiwctnevaunlanranca tera vons incr a a a a A 15 Classification of vibration values for machines groups 1 and 3 eee eeccceeeeeeeeeeeeeeeeeaeeeesaeeeees 16 Classification of vibration values for machines groups 2 and 4 eee ceeccceeecceeeeeeeeeeeaeeeeeaeeees 16 Values setting in A4900 Vibrio III Ut sccsceenaeceteccnnetontonslocs tesdustewnoisd davinb adiweakedenmoaaeeaiovenss 16 QUICK SIAN seccicec ceca seca oe tse E aaa 17 Preparation of Measurement POInt cccccecccseeeseeeeeeeeeeceeeceeeeeeeseeeeeeeeeeeseeeeeeeeeeseeeseeees 17 POWNO Is BAL CC Sorrera E 17 Plugging IN Vibration Senso ssie an aa aa elected 18 GONMECIORS top DANEI ao a a a ea E Gear So aet ey 19 ViDration Measurement rasiaan a oitia ites cienltetie testa cielasitestiunltaats 19 Temperature MCASULEMEM vcs sicccseutecews st aceeettasensalewaceeettideesalevaceeeitens cduaceeaties dace 19 Automatic detection of the machine SPEE ccccceeccseeeceeeeceeeeseeeseeeeeeeeeeeeeseeeeseeesaeeess 20 Evaluation of the machine and bearing conditions ccccccseecceeeeceeeceeeeceeeeneeeeeueeseeeeaes 20 Fault Source Identification
20. able 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 disadvantages 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 7 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Fault Source Identification and Diagnostics Tool This tool is included in the Adash 4900 Vibrio III It is good message for users because such function has never been built in the instrument in this price category This function display several bar graphs with traffic light colours Two major largest bars are allocated to general machine condition on the left side and ball be
21. ally equipped with sleeve bearings Group 2 Medium sized machines rated power from 15 kW to 300 kW and electrical machines with a shaft height between 160 and 315 mm These machines are normally equipped with rolling element bearings Group 3 Pumps with multivane impeller and with separate driver with rated power above 15 kW Group 4 Pumps with multivane impeller and with integrated driver with rated power above 15 kW 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 15 Further technical and contact information can be found at www adash eu 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 in s Rigid R13 2 3 0 09 A B 4 5 0 18 B C 7 1 0 28 C D Flexible F13 3 5 0 14 A B
22. and Diagnostics TOOIL ccccecceeceeeeceeeeeeeeeeeeeeeeeeeeeeseeeeaeees 20 TRE SUODOSCODC aici a Sadat al siete a e Ea 21 PNET eeke E eee eee eee oe ee 22 Instrument Operation A 23 SWitehng omand Ossana has hex oeassinsiadibexo Sian ie woe eee 23 aNd DYMO dE aan a E a tae Renee E er ean ae meets eres ee ee ora eee 23 Halfeldaare tC 9 il La ssaeenemes seers mete a etn hose re tye en nen TnI SS eto in ee ee et ee 24 Using Ol earphones sreysre sate satenten cde sadaaaenct atueeratac T 24 Selecion Of MECASUFEIMEMT a5 conccsstccernvackecetunsweecannsieaenepeacaanoneiemenaneereauia teen aa aguante 25 Measurement Methods SCIEN seisscrcrasascnssarnownasannasahenah dacesnasienaleipndienkdensabaadenenmiegaasanergennaens 25 Speed detection And definitio iseset e a a a a N 28 Menu Or TUNCHONS SEIECUOM e casiainniaa aaa 29 HGAT cenar E E E a AA eta ala Shade 29 STROOBOS A A a 30 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III VOLUN Seether enn ene meee Rene ees ne ee rt ee rune ket ane emer enone amt oe henna Mer CS anne Aeneas heer 30 SEPE ag cases ee acted ness dete Reseiea E snante ssi A eecdone teens en neabiaaeueese eae 31 Oe Ee ine eases N A ecdonesemne ea peadieteseest eae 31 ALARN Orein A EOE 32 ENEI TEE EE LAA AEAEE A EO E E A E E E A AEE EAT 32 DISPLACEMENT VALUE cisccccciccsccsssisiscsnccsasecsnaesnconternsssatasiaseauesudeousdunndendessnsasnessonssandeuacerdteonannnt 33
23. aring condition on the right side PSO REM ce The next three bars are located in the middle They display the severity level of UNBALANCE LOOSENES and MISALIGNMENT from the top Measurement Points The measurement location must 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 should determine measurement points on the machine The typical machine together with the measurement points on the picture MP 14 FANT 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 be usually performed horizontally vertically or in another angle The importance of the angle choice should not be overstressed choose any radial direction with easy access 8 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III 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 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 sa
24. batteries transport case CD with the manual 42 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Response specification Adash 4900 Vibrio Ill Vibration velocity measurement frequency response A dB an 1 10 100 1000 10000 log F Hz Measurement accuracy 10 mm s RMS input signal is 2 5 5 500 Hz frequency range and 5 500 2000 Hz range Vibration acceleration measurement frequency response A dB 0 1 1 log F kHz Measurement accuracy 1 g RMS input signal is 2 5 in 0 2 20 kHz frequency range Velocity measurement amplitude response Measurement accuracy for RMS vibration velocity 0 1 100 mm s range on 80 Hz reference frequency is 2 5 Acceleration measurement amplitude response Measurement accuracy for RMS vibration acceleration 0 1 10 g range on 8kHz reference frequency is 2 5 43 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Calibration recommendations Sensor sensitivity Before any calibration you need to know what exact sensitivity of sensor is s
25. boscope 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 21 Further technical and contact information can be found at www adash eu 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 Ill because this instrument has built in torch in front panel See the Menu chapter for details 22 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Instrument Operation Switching on and off The instrument is switched on by pressing of the middle button O Instrument on off button Fig Buttons Switching the instrument on Provided that batteries with sufficient voltage 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 Fig Switching on with Fig Switching off weak batteries Description of numbers in initial screen 1 The sensor sensitivity mV g times 10 983 means 98 3mV g 2 Firmware version V2 05dtH
26. e 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 lt is not possible to simply define limit vibration values in general for a wide range of machines However it is possible to create the standards 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 6 Further technical and contact information can be found at www adash eu 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 veloci
27. e of machines Its reliability would be low then It would happen you will repair machine which do not require it The standards should be rather determined for a narrow range of machines A4900 Vibrio IIl contains Adash limit values and ISO 10816 limit values Adash limits are not rewritten from any existing standard 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 colours are taken from traffic lights green amber and red All limit values are related to the speed value The low speed machine should generate lower vibration then higher speed machine In the graphs area you found three particular areas GOOD condition is the space up to the yellow line that means operation without restriction The space above yellow but under red line is an ALERT condition Possible to operate the machine but have to be more checked It s necessary to determine the source of worse co
28. e to operate with paying more attention and planning of repair RED COLOR There is the serious defect level found on the machine Machine shouldn t be in operation 41 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Adash 4900 Vibrio Ill Specifications Input 1x ICP powered accelerometer Input range 60g PEAK with standard 100mV g sensor e g 600g PEAK for 10mV g sensor the sensitivity is editable in the unit Measurements Detection Unit Frequency Range Displa RMS PEAK RMS Pog S0016000 Hz 0999 RMS g 150016000 Hz 0999 RMS Pog S000 Hz 099 RMS PEAK Time Signal g 50016000 Hz 09993 Spectrum 200 lines Temperature C F YB IES Display colour OLED display 128 x 128 pixels diagonal 1 5 88mm Further functions LED stroboscope 0 17 Hz 300 Hz 10 RPM 18000 RPM LED torch Output 1x AC signal 8 Q 0 5 W for external headphones signal listening Power 2xAA 1 5V batteries alkaline NIMH LiFe Temp Operating 5 to 50 Storage 20 to 65 Degrees Celsius Dimensions 150 x 60 x 35 mm Weight 350 g including batteries without cable sensor and magnet 540 g including batteries cable sensor and magnet Accessories vibration sensor coiled cable to connect vibration sensor magnetic base for vibration sensor earphones recording cable with 3 5 mm jacks measuring tip for manual pressure on the sensor 1 5V alkaline
29. eak vibration values in the ranges 10 Hz 1000 Hz in mm s 0 5 kHz 16 kHz ing nlll mm s 200Hz Spectrum 200 Hz looseness detection FFT analysis of vibrations in the range 0 Hz 200 Hz in mm s RMS with display of 3 maximum peaks found The peaks are ranked according to amplitude vibration size Time signal for roller bearing diagnosis Measuring of time signal and vibrations in the range 0 5 kHz 16 kHz ing Displays actual measured time signal and geny value 26 Adash 4900 Vibrio III Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Vibrations in frequency ranges gearbox bearing Measurement of RMS vibration values in the ranges 0 5 kHz 1 5 KHz ing 1 5 KHz 5 kHz ing 5 kHz 16 kHz in g Fasit expert system The FASIT screen It displays the severity levels of machine faults Also the temperature bar is displayed on the right side When the RPM is not found then no results are displayed from ver 2 05 082 M Overall RMS and Peak displacement values in the range 2 200 Hz in mm From ver 2 05 is the displacement displayed in um 2 Further technical and contact information can be found at www adash eu 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 detection
30. eeeeeeeeeeeeeeeseeeeseeesaeeens 43 Calibration recommendations cceccceeecencensecnseensecanecenecenecenecenesesecenesenesenesenesensseneseness 44 SENSON SENSIVA a pas tedaos acade inate tesdawucerganedenneeus 44 Basic test with A4801 Sensor SIMUIAtOl ccccececeeeeeeeeeeeteeeteneeneeeeeeeeneeeneeeneeteneegenes 44 Basic 16st Witt sensor AIG SMAI 6 asarni Na 44 Advanced tests of velocity MEASUFEMENT cccceccceeecceeeceeseceeeeceeeceuseseueseueessueeseeessaeens 44 Advanced tests of acceleration MEASUPEMENL ccceecceeceeceeeeeececaeeceeeseesaeeaeeseeaeeees 45 Envelope demodulation tOSt ccccccccseccceeeccececeuccceeeceucecseeeceeceueeseuecsueesueeseeesueeneeeseas 45 3 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Why perform vibration diagnostics Vibration diagnostic allows checking the condition of all your machinery You will be informed early about potential failure before the machine gets damaged and you will be able to order only real specific required maintenance instead of expensive overhauls The periodical measurements will allow you to keep your machines in good health 4 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Why A4900 Vibrio lll You always ask before you make a decision to buy the new instruments what unit is the best for your needs Is
31. es measuring tip for putting manual pressure on vibration sensor 1 5V alkaline batteries CD with the manual Fig Adash 4900 Vibrio III with accessories 11 Further technical and contact information can be found at www adash eu 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 sensors 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 EARPHONES WARNING Listen at moderate volumes to avoid hearing damage Remove the earphones from the ears when you move the sensor or re connect cable 12 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Standards for vibration measurements Using a standards 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 rang
32. es are stable Attention Use the measuring tip only in hard to reach places where it is not possible to place the magnetic base Temperature measurement Infrared sensor for temperature measurement is aside from accelerometer input Measurement angle is about 45 degrees around the sensor centre axis Best results are taken with sensor distance 10 20 cm from measured surface The accuracy of result depends of emissivity this is typical property of IR temperature sensors 100mm dia 200mm 80mm dia 160mm 60mm dia 120mm 40mm dia 80mm 20mm dia 40mm 0 00 80 60 40 20 0 20 40 60 80 FOV sensor 90deg Sensor sensitivity vs the angle The size of the scanned area vs distance 19 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Measured temperature is displayed in Celsius and Fahrenheit degrees Also the coloured bar is used The bearing symbol on the other displays is also coloured according to the actual temperature value The ranges of colours are for less then 30 green 30 45 yellow 45 60 orange 60 75 red and for greater then 75 dark red Automatic detection of the machine speed Its 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 energ
33. et in the instrument See the initial screen which contains this information Description of numbers in initial screen 1 The sensor sensitivity mV g times 10 983 means 98 3mV g 2 Firmware version V2 05dtH 3 HP filter frequency for bearing in kHz 0 5 kHz The sensor sensitivity is not equal 100mV g very often The sensitivity of sensor is usually in 95 105 mV g range Let suppose the sensitivity which is set in the instrument is equal S Then all calibration measurements which are adjusted to the sensitivity 100mV g must be multiplied by 100 S Basic test with A4801 Sensor Simulator If you have the A4801 unit you can regularly test the unit on two frequencies 80Hz and 8kHz On the initial A4900 screen are displayed RMS values of velocity and acceleration The velocity value should be 10 mm s and the acceleration should be 0 5g The signal from A4801 is adjusted for exact 100mV g sensitivity When the sensitivity of A4900 unit is e g 95mV g then the higher values 10 5mm s and 0 53g will be displayed Expected values from the A4801 should be multiplied by 100 95 coefficient Basic test with sensor and shaker The procedure should be the same as with A4801 Set on the shaker 10mm s on 80Hz and check the RMS velocity value on the initial screen Then set 0 5g on 8kHz and check the RMS acceleration If you have trouble to generate the 8kHz you can use lower frequency but not lower then 1200Hz Bellow this limit the LP fi
34. hat 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 OUT COMPLETELY 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 motor 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 In the end put the cover on the pad Listening to Vibrations Using Earphones A user can connect earphones 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 Analysis 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 distinct rumbling sound is audible in the earphones then If the bearing is OK then you can hear only a weak noise EARPHONES WA
35. he 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 Pre set frequency in RPM and Hz 1500 pew 75 00 pH Pre set step V A i a increasing 1 RPM l decreasing Fig STROBO mode 1RPM 10 RPM AJI Options of Kilgi Y mee frequency step 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 earphones are off the symbol is grey Next press of the button returns the instrument back to the measurement mode till Switched off aulllll Maximum Fig Volume adjustment Fig Displayed volume cca 50 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 earphone amplifier by excessive volume This will distort a signal in the earphones You can use any stereo or mono headphones with nominal impedance higher than 8 Q Both output stereo channels are connected to the signal 30 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III SETUP ALARMS UNITS ESC Further fu
36. ltering is applied and the result would be distorted Advanced tests of velocity measurement Use the shaker and sensor You can make the frequency response and the amplitude response Use the amplitude 10mm s for frequency response test Change the frequency from 6 to 1200 Hz and check the filtration curve which is drawn in previous chapter Also the accuracy is mentioned there Set the 80Hz for amplitude response Change the amplitude from 0 1 to 100 mm s and check the accuracy 2 5 44 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Advanced tests of acceleration measurement Use the shaker and sensor if you are able to shake high frequencies 10kHz or more If your shaker system does not allowed it use the signal generator and switch the ICP off Contact your re seller for information how to switch the ICP off That information is not written in this manual You can make the frequency response and the amplitude response Use the amplitude 1g for frequency response test Change the frequency from 500 to 12000 Hz and check the filtration curve which is drawn in previous chapter The accuracy is 2 5 set the 8kHz for amplitude response Change the amplitude from 0 1 to 10g and check the accuracy 2 5 Envelope demodulation test The envelope value is RMS value Do not use comparing with peak values Use the 8kHz pure sine signal with 1g 100mV amplitude The
37. me 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 screwed 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
38. nctions menu appeared Choose requested function using arrows and confirm by Enter SPEED AUTO OFF Switch on AUTO ON or switch off AUTO OFF automatic detection of RPM The manual enter is required when AUTO OFF MANUAL OFF ESC For ver 2 05 and higher more options are available AUTO automatic speed detection MANUAL always manual entry of speed OFF speed value is ignored no limits with relation to speed are used 31 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III ALARMS R13 F13 R24 F24 Standards setup Alert limits amber colour and Danger red colour will be defined See Standards for vibration measurements chapter 4500 RPM Chosen standard is displayed above the machine symbol F13 in this case If Adash standard is chosen nothing is displayed UNITS SPEED ALARMS ESC To change the UNITS go to SETUP menu and then MEASURE menu 32 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III IMPERIAL ESC Vibration speed unit can be chosen here mm s millimetres per second for Metric units and ips inch per second for Imperial units are available Device remembers chosen units even after switch off DISPLACEMENT VALUE RMS 7 P P 0 P P P ESC Displacement value setup 3 options are available See above picture Confirm
39. ndition and plan repair for instance change the bearing or maintenance balancing alignment The space above red line is an DANGER condition and the machine should not be operated First figure contains the values 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 condition 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 condition is GOOD green If the value is above amber but under red then the condition is ALERT amber If the value is higher then red graph then the condition is DANGER red 13 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Adash Limit Values of Machine and Bearing Vibrations Graphs according to which the instrument determines acceptable vibration limits depending on machine speed
40. ondition GIAQNOSTICS cccecceceeeceeeeceeeeseeeteeeeseeeeeeeeseueeseeeeaueesaees 7 Methods for ball bearing condition CIAQNOSTICS cccecccsececeeeeceeeeeeeeseeeeeeeseueesseeeaeeeseees 7 The relation between gears and ball D ArinGS cccceececeeeeseeeeeeeeseeeseeeeseueeseeesseeenseeeaes 7 Fault Source Identification and Diagnostics TOOl cccccccceccceeeceeeceeeseeeteeeseeeseeeseeseeees 8 ME ASUFEMENTE PONIO sicrceuitececstitencetteereact E E E E EE 8 The preparation of the measurement point s nn nnenoenoenoennerrerrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrenne 9 Listening to Vibrations Using Earphone s ccccceeccceeceeeeeeeeeeseeeeceeeeseeeseueeseeeaeesaeeesaees 10 Relationship of Measuring in Acceleration and Speed cccceccseccseeeeeeeeeeeeeeeeeeeeeeeaees 10 Abbreviations used in the guide cc 2iue ciaviveicidutyaienityelaioine ciivivsicaivival siieieencdiaelaiieie 10 What Will You Get with Your Instrument naannnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn ennnen 11 mstr ment and ACGESSONCS esre a a 11 Before Yo St ll racisvesineindevencatasatietoireninievideinipeuneindencsndenvaninlenneeinimun tines ndenntinloninigt 12 Standards for vibration measurements ccceeeeeeeeeeneeeeneeeneeeeneeeneesenseeesssoneeseneeonnesons 13 Adash Limit Values of Machine and Bearing Vibrations cccccceececeeeeeeeeseeeeseeetaeens 14 ISO TOS U6 limit valle Siirteen
41. 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 without 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 surface 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 Measurement repeatability means that you will be able to compare values well 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 f 1 Press gently Fig Opening of the lid 17 Further technical and contact information can be found at www adash eu 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 g sensitivity The instrument is
42. r connecting of earphones and listening to a measured signal We can connect the earphones 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 earphones Advisable volume can be set up by the VOLUME item from the instrument menu see MENU chapter Decrease volume Increase volume button button Switch measuring volume control button 24 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III Selection of Measurement A selection of measuring screen method can be performed by arrow buttons W 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 1140 RPM 1140 REM Overall RMS values Measurement of RMS vibration values in the ranges 10 Hz 1000 Hz in mm s 0 5 kHz 16 kHz ing with estimated value of machine speed frequency Based on the speed and vibration values of the machine condition colour of displayed value green amber red is determined The colour of bearing is determined regarding to the measured temperature 25 Further technical and contact information can be found at www adash eu ADASH Ltd Overall PEAK values Measurement of p
43. s 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 of 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 diagnostics solves two basic tasks 1 Diagnostics of machine mechanical failure imbalance misalignment mechanical looseness 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 doesn t necessarily mean good condition For example if a bearing was installed incorrectly then there will be 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 caused by material fatigue can develop in several seconds only cracks breaks The proof of the diagnostic performanc
44. s are also parts of 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 3 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III This screen is important for detection of 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 frequency see the value description on the bottom probably 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
45. termines the condition of your bearings including slow running ones Identify insufficiently lubricated bearings Indicates unbalance looseness misalignment Check unbalance alignment and loose foot Check machine speed by built in stroboscope Check machine temperature by Non contact temperature meter Measures in either Metric or English units Operation of A4900 is easy to use Colours green orange and red display the status Determination of individual machine or bearings defect types is done directly during operation without need of use a computer or software Despite the A4900 is very compact and rugged it is designed and fits in the palm of a small hand Nevertheless the A4900 is big in performance The A4900 is supplied complete set with an accelerometer coiled cable magnetic base transit case and earphones You can connect earphones to listen to machinery noise related to vibration and process When measuring transmissions or slow running bearings you will quickly appreciate the benefits of the earphone accessory 9 Further technical and contact information can be found at www adash eu 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 When we are talking about the vibration diagnostic
46. ty 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 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 repeat
47. y 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 However the correct speed which must be defined for condition levels can be entered manually as well 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 COLOR Machine is in good condition no defect is found The operation is without restrictions 2 ALERT AMBER COLOR The beginning defect has been found on the machine It is possible to operate with paying more attention and planning of repair 3 DANGER RED COLOR Serious defect has been found on the machine Machine shouldn t be in operation Special functions are included in the instrument for detection of that three states The overall vibration values are coloured with appropriate colour The vibration limits Adash for each state are determined from the graphs which are printed in the Adash Limit
48. y 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 36 Further technical and contact information can be found at www adash eu ADASH Ltd Adash 4900 Vibrio III 2 ALERT AMBER COLOUR The beginning defect has been found on the machine It is possible to operate with paying more attention and planning of repair 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 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 Shocks which cause these defect
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