VIBER X1™ Manual - VMI International AB
Contents
1. To return to vibration measurement press the symbol again Measuring point location Measurements should be taken on the bearing housing or as close as possible and in the horizontal vertical and axial directions Bearing Bearing a Vibration Measurement Instruments How to make good measurements The sensitivity direction of the transducer coincides with the center axis of the transducer Use the built in magnetic mount by gently placing the accelerometer onto the mea surement point Wait a few seconds for the accelerometer to come to a steady state to reduce unwanted noise If you are connecting to a non magnetic surface push firmly against the measurement point Make sure you have good contact with the machine It you are measuring on a curved surface make sure the accelerometer is attached and not moving back and forth Attach the transducer in a verti cal horizontal or axial direction if possible Note if the reading is stable or fluctuating The non stable reading is also valuable information used to determine the vibration cause When the transducer is mounted with the magnet the frequency range of the measurement is reduced to about 2000 3000 Hz depending on the flatness of the contact between magnet and surface Note Using the magnet can change the bearing condition value High frequency vibration can sometimes be difficult to col lect because high vibration does not transmit through the machi2. If the simultaneous vibration caused by unbalance is 4mm s by misalignment 2 mm s and by the gear mesh 5 mm s then the total vibration measured with VIBER X1 is 6 7 mm s Total vibration N4 4 2 2 5 5 6 7mm Notice that a reduction of the unbalance from 4 mm s to I mm swill reduce the total value from 6 7 mm s to 5 5 mm s a Vibration Measurement Instruments The ISO standard classifies the machines differently if the machines are flexible or rigid This reflects the location of the machine s stiff body resonance related to the basic run ning speed of the machine For example a machine supported by rubber or springs have a resonance at low running speeds The machine starts vibrate at a low rpm When the speed is increased above these resonance frequencies the vibration is redu ced This machine is considered flexible Resonance is easily found when a flexible machine is running up or down in speed The resonances are located at the speed where the vibration has a local maximum level Extraction s from ISO 10816 3 Industrial machines with power above 15kW and nominal speeds between120 15000 r min Unit Group 1 and 3 Group 2 and 4 1 4 2 3 2 3 2 8 4 5 7 1 10 a Vibration Measurement Instruments Modern machines often run at high speed and bearing supports are flexible foundations should can be evalua ted as flexible even when it is not mounted on rubber or
3. 7 Instrument including battery and transducer Obs You should avoid using other accelerometers because of instrument calibration If you change the accelerometer the instrument must be calibrated to preserve the accuracy 17 Vibration Measurement Instruments We reserve the right to modify or improve the designs or specifications of our products at any time without notice Declaration of conformity VMI declares that the Viber X1TM is manufactured in conformity with national and international regulations The system complies with and is tested according to following requirements EMC Directive 2004 108 EC Low Voltage Directive 2006 95 EC 8 August 2011 CE E 8 August 2011 Vibration Measurement Instrument International AB VMI 18 HE Vibration Measurement Instruments L Warranty disclaimer VMI warrants the products to be free from defects in material and workmanship under normal use and service within two years from the date of purchase and which from our examination shall disclose to our reasonable satisfaction to be defective Warranty claimed products shall be returned prepaid to VMI for service We reserve the right to repair or to replace defective products Always try to explain the nature of any service problem by e mail or telephone Check first all natural problems like empty batteries broken cables etc If returning the product be sure to indicate that the purpose
4. ange and correct these items in later issues without further notice Also changes in the VIBER X1 equipment may take place that affect the accuracy of this information Vibration Measurement Instruments VW ze Instrument overview The VIBER X1 is a portable vibrometer to be used in preventive and pro active maintenance work especially on rotating machinery A complete set consists of an instrument carrying bag a vibration transducer with magnet support and charger VIBER X1 measures the velocity mm s RMS in the frequency range 2 Hz maximum frequency The instrument has the capability to measure up to 40 kHz the limiting factor is the accelerometer The accelerometer provi ded with the Viber X1 measures up to 15 kHz The frequency range can be set by adjustable filters High pass filters can be set to 2 Hz or 10 Hz Low pass filters can be set at 1000 Hz or maximum frequency This range covers most of the frequencies that will occur for the majority of mechanical failures and defects Examples are unbalance looseness resonance misalignment of shafts and gears cavitation and other fluid generated vibrations The vibration alerts are supported by several vibration stan dards The close comparison between vibration levels and actual machinery wear will build up your knowledge Use this experience to determine the action required when high vibrations are found A common standard for vibration is ISO 10816 3 a
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6. e with the unit g We use acceleration because high frequencies give a larger signal compared to velocity if measured in acceleration When the balls or rollers rotate inside the bearing a wide band noise and vibration occurs This noise and vibration increase if the bearing is poorly lubricated overloaded due to misalignment or has a damaged surface If the selected frequency band includes low frequencies the bearing condition value would also include vibrations from unbalance misalignment etc and not only from bearing vibrations 13 4 jm Vibration Measurement Instruments If the selected frequency band only includes very high frequency noise and vibrations we would need special vibration transducers that are very rigidly and closely mounted to the bearing because the machine structure works as a mechanical filter for high frequencies VIBER X1 measures the bearing condition value between 500 Hz to 16 kHz Normal machinery vibrations rarely have vibrations above 500 Hz Note A high bearing condition value is an indication and a recommendation to continue with other fault analysis High bearing condition values can appear at gear boxes converting machines with cutters and similar machines without any bearing faults because they naturally pro duce frequencies above 500 Hz 14 Vibration Measurement Instruments Bearing condition value with unit g RMS The diagram below is a g
7. g Vibration Measurement Instruments a 78 VIBER X1 VIBER X STN TTS 2 40 ux 0 Nut O o me ete W e ej 3 i Manual Ver 1 4 Vibration Measurement Instruments Our X series of hand held instrument VWIBER X2 VIBER XI BATTERY VIBER XI VIBER X2 VIBER X3 VIBER X5 a Vibration Measurement Instruments Important information Safety precautions Vibration measurement and balancing involves measurement on rotating machines Keep a safe distance away from rotating parts Secure transducers and cables from rotating parts Always follow company local and national security regulations When working with weights on the rotor always follow lock out tag out procedu res Secure the start switch with a lock and also use the emergency switch for dou ble safety This is especially important when the machine is remote controlled VMI International AB takes no responsibility for any accidents on people and machines VMI International AB and our authorized dealers will take no responsibility for damages on machines and plants as the result of the use of VIBER X1TM measurements Even though great efforts are made to make the information in this manual free from errors and to make the information complete for the user there could be items we have missed because of the large amount of information As a result of this we might ch
8. is to make repairs and indicate the original invoice number and date of shipment Warranty exclusions Damage not resulting from a defect in material or workmanship or by other than normal use Damage resulting from repairs performed other than by an authorized service center The limited two year warranty and remedies contained herein are in lieu of all other warranties expressed or implied including any warranty of mer chantability and any warranty of fitness for a particular purpose and all other reme dies obligations or liabilities on our part In addition we hereby disclaim liability for consequential damages for breach of any expressed or implied warranty inclu ding any implied warranty of merchantability and any implied warranty of fitness for a particular purpose The duration of any implied warranty which might exist by operation of law shall be limited to one year from the date of original retail purchase NOTE Some countries do not allow the exclusion or limitation of consequential damages and some countries do not allow limitation on how long an implied warranty lasts so the above exclusions or limitations may not apply to you This warranty gives you specific legal rights and you may also have other rights that vary from country to country If you have problems with your instrument during or after the warranty period first contact your distributor you purchased the unit from 19 VMI International AB Sweden www vmiab
9. mall vibrations None or very small bearing wear Rather low noise level e 3 7 mm s Noticeable vibration levels are often concentrated to some specific part as well as direction of the machine Visible bearing wear Seal problems occur in pumps and increased noise level Keep the machine under observation and measure at smaller time intervals than before to detect a deterioration trend if any Compare vibrations to other operating variables e 7 18 mm s Large vibrations Bearings running hot Bearing wear out causes frequent replacements Seals wear out leakage of all kinds evident Cracks in welding and concrete foundations Screws and bolts are loosening High noise level Plan action soonest Do your best to discover the cause You are wearing down investments quickly 12 g gt Vibration Measurement Instruments YW e 18 mm s Very large vibrations and high noise levels This is detrimental to the safe operation of the machine Stop operation if techni cally or economically possible Few machines can withstand this level without damage Reduce any further running time to an absolute minimum CO lt Bearing condition symbol Press the bearing symbol The instrument measures the bearing condition value Bearing condition value is the RMS value of all high frequency vibrations in the range of 500 Hz to maximum frequency This average has the unit g Bearing condition value This value is an averag
10. nd may be available from domestic standardisation authority This standard in use for decades worldwide is an upgrade and excellent for continuous and long lasting operation of machinery Vibration Measurement Instruments Ll Functions lt q Power on the instrument Press the On Off key and the instrument starts to mea sure vibration default is 2 Hz maximum frequency range the LED s indicate the low and high pass filter setting The instrument shuts off automatically after approximately minutes if no keys are pressed lt q Increase display brightness Use this button to increase display brightness OBO Changing frequency range The Viber X1 is one of few analog instrument availa ble with adjustable frequency ranges Use the up down arrows to change the filters The LED lights up to show the filter in use Use this to compare measurements in the same range Note the old ISO standard had 10 1000 Hz as frequency range We recommend you to use 2 1000 Hz as a standard range BAT Vibration Measurement Instruments j n Battery check VIBER XITM features a battery check When less than 10 of the battery capacity remains the battery LED will flash Start measuring vibration on the machine then press the symbol key for bearing condition measurement The instrument mea sures instantaneously a Bearing Condition value in the range between 500 Hz to 16 000 Hz
11. ne for long distances Pressing the transducer more firmly should not change the reading If in doubt always try to adjust the contact point first Secondly if necessary mount the transducer with the M6 stud 7 a Vibration Measurement Instruments All normal measurements on vertical or horizontal machinery should follow the three perpendicular axes of true vertical horizontal and axial directions The VIBER X1 is mainly intended for measurements against the machinery housing and bearings to compare to standards VIBER X1 can also be used to measure other compo nents such as piping valves etc Note In some cases the mass of the transducer may influence the reading A good rule is to avoid readings on surfaces that are 10 times lower in mass of the trans ducer LJ Vibration Measurement Instruments L How to interpret vibration measurements A user with no previous experience should use the ISO 10816 3 standard The standard normally calls for a velocity measurement in mm s RMS To better understand what this mea surement means think of it as how fast the machine is moving back and forth This measure gives a good understanding of the amount of break down energy causing mainly wear and fatigue in the machine or the structure The instrument measures the total RMS vibration value in the frequency range This RMS value is the average sum of all the measured vibrations Example
12. springs The ISO 10816 3 standard allows for slightly higher limits when a foundation is considered flexible than rigid A conclusion from this is a resonance condition should not be allowed or at least must be avoided at operating speeds In practice this also includes the double speed as well as any other natural excitation frequency such as blade passage A great advantage with proper vibration measurements and the use of vibration standards is that you can judge the future maintenance cost reliably at start up If you find levels above 3 mm s RMS it s a risk that the mach ine will have higher maintenance cost The specific cost and action is specific to the machine design The next logical step if you want to improve the ac curacy of measurements is to use more advanced analyzers like VIBER X2 X3 or X5 to learn and detect the frequency behind the vibration and thus the exact mechanical fault The practice of this is beyond the scope of this manual 11 Vibration Measurement Instruments Recommended vibration levels in mm s and common findings The following is an extraction of part of the old standard ISO 2372 class 4 large machines on flexible foundations with some common findings added Use this simplified list as a first indication when approaching a newly commissioned machine or after some time in operation Investigate the reason for any machine that vibrates above 3 mm s RMS e 0 3 mm s S
13. uide to identify the bearing condition value If vibrations of other causes e g flow surge gear mesh are within in the frequency range 500 16 000 Hz this can give a high bearing condition value without the bearing being damaged A high bea ring condition value can also be indicated if the bearing is poorly lubricated or overloaded g 50 Vibration Measurement Instruments Technical data VIBER X1 Vibration transducer Accelerometer Standard momi 100 asie to thg mV g instrument Input amplitude Max 20 g RMS With other sensor up 2 1000 Hz 10 1000 Hz 2 Max Hz 10 Max Hz presentation Signal processing Analogous Accuracy Operating time Min 24 or 12 hours 3 charged battery Note 6 External charger 5 0 V Lithium or 7 5 V NiMH AAA Enclosure protection IP65 Operating temp 20 to 60 C range 285 gram Note 7 Size Lx W x H 125mm x 70mm x 40mm 16 Vibration Frequency range Vibration Measurement Instruments Technical data VIBER X1 Note 1 Note 2 Note 3 Note 4 Note 5 Note 6 User selectable User selectable Full scale is 199 9 mm s for vibration Over 0 05 gBC Capacity of batteries is 2300 mA h for lithium and 1100 mA h for NiMH If using alkaline batteries never connect a charger to the instrument storage temp 20 to max 60 C Operating times depends on intensity on the LED s and type of batteries Ca 24 hours for Lithium and Ca 12 hours for NiMH Note
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