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DIAMOND 401 user manual - roga

1. The power supply socket is described on the back panel of the instrument he central pin of the socket should be connected to the positive end of power supply A Only the power pack cables and accessories provided together with the instrument or recommended by the manufacturer are compatible and may be connected to the instrument Using other accessories and cables may damage the instrument and invalidate the warranty 1 2 4 Connecting cables DIAMOND 401 9 User s guide Vibration sensor Temperature Laser sensor speed sensor m lt lt z 2 z E 5 E U U U Thermocouple adapter MEMU START STOP MACHINE MAGHINE MEMORY lt gt POINT FLAT OPTIONS A ESC al POWER CHARGIBAS DIAMOND 401 10 User s guide 1 3 Carrying case Reflecting tape Accelerometers with mounting magnets 9V DC power pack DIAMOND 401 ib l i NA NETTA AN o AGU J z cratic ney i ME S Eeri A V n sovy may M WZNOSI sna User s guide DIAMOND 401 11 2 Operating the Diamond 401 2 1 Power supply Normally the instrument is powered from the built in rechargeable accumulators four NiMH accumulators Alternatively it may be powered from the external 9 VDC power supply included with the instrument which is also used to charge the batteries It connects to the external power supply socket The diode on the front panel is turned on when external power supply is connecte
2. PZ The first measurement that was recorded for this point is then highlighted With the and Vv we can select another point To delete the selected measurement we should press the key that is just underneath the word Delete i keys instead we press the key then the corresponding result will be displayed on the screen The letter M on the top of the screen reminds that this measurement is displayed from the memory To return to the list of measurements we should either pres the key i Pressing again the key or selecting Exit will get us back to the departure level in the memory where we can select another machine and the measurement point number DIAMOND 401 38 User s guide 2 12 1 3 Repeating a recorded measurement Should we would like to repeat a measurement that was previously recorded in the regular memory then we just need to highlight this measurement and press VIKO The question whether we want to repeat the measurement will be displayed on the screen and when we answer YES then we shall be asked to confirm our choice In case of positive reponse the measurement will be executed To stop the measurement we press the button S02 To return to the memory menu we should either press or choose the word Exit At the moment when we return to the memory menu the old measurement is replaced by the new one 2 12 1 4 Erasing the regular memory The choice of the memory type or the complete era
3. editing a value is the following DIAMOND 401 14 User s guide we start the editing by pressing the key On the display appear two positions that To get to the other position we use the horizontal arrows pressing pa we confirm the selection and if we want to cancel the selection and return ESC to the previous value then we should press G The table below shows the possible choices for the parameters and the measurement ranges Measured quantity RMS P EB Measurement ranges Symbol Measured quantity RMS P K P P P K A Acceleration X X X 5 50 500 m s and AUTO D Displacement X X X 50 500 5000 um and AUTO V D Velocity X 50 500 mm s and AUTO Displacement X X Explanations A vibration acceleration measurement V vibration velocity measurement D displacement measurement V D simultaneous measurement of velocity and displacement Such measurement simplifies the machine condition evaluation it is recommended by the ISO 10816 3 standard AUTO automatic selection of the measurement range The instrument samples the signal and selects the adequate range The signal is evaluated on continuous basis and if necessary the range will be changed During the change no result is displayed and instead there are displayed flashing horizontal lines For each quantity being measured it is possible to choose the desired frequency band The choice of available filt
4. m dHe mi Pe Bock Hest Setup Similarly as in the case of one plane balancing we can break down the correction masses in order to place them at the reserved for this purpose locations The center button arrow below P1 P2 allows us to switch between planes Balancer 1P Correction mass Plit tor F1 mO F1 446 74 99 movFi 1 ADD 20 64 moF4 2 S60 62 54 Return PAP Setup Next we install these masses at the indicated locations each on its respective plane and we do the measurement to see the improvement resulting from the correction masses m0 Balancer ZF Check run with corr n gt naj ZE 48 ZA 245 Bock Hest Setup We continue the procedure with the correction masses m1 and following the total number is limited to 10 each for its respective plane until we obtain the satisfactory results 2 11 Measurement overload DIAMOND 401 36 User s guide The overload occurs when the signals amplitude exceeds temporarily or permanently the measurement range and it results in signal deformation The user should be immediately informed about its occurrence since the overload introduces a significant measurement error In DIAMPOND the overload is signalled by a symbol of lightning that appears in the upper left corner of the display overload signalization Meter A vo rose 10H2 1UkHz RMS i P K i P P 12 7 34 7 67 7 Exit Evaluation SetuP This symbol tells the user that the measureme
5. so we cannot change this parameter and V is displayed for information only Tracking filter defines the bandwidth of the tracking filter The choice is between 0 05 Hz and 0 5 Hz Typically for the machines rotating at speeds greater then 600 rpm the 0 5 Hz filter will be used while for the rotations below 600 rpm the 0 05 Hz filter is recommended Range measurement range choice is similar like with the other measurements The arrow underneath the word Range indicates that there is another screen with more parameters to be setup DIAMOND 401 27 User s guide Ealancer ZeTuF k Averaging Ho of re Ho ot tied location Correction mass Ho of channel r Return Averaging No of rev number of rotations used to calculate the average rotating speed No of fixed location Correction mass No of channels cont d Input for 1 P Sensor Input for 2P P1 Sensor P1 contd DIAMOND 401 The choice is between 1 and 99 indicates the number of locations that are available on the rotor for the installation of corrective masses These locations should be disposed uniformly in the correction plane Is it possible to program between 3 and 90 locations for information only add means that during the edition of the test weight we indicate the location where this weight should be placed Also when we interpret the result the angle indicates the location where to pl
6. time until the preventive actions are undertaken condition still temporarily acceptable D the vibration level in this category is considered to be serious enough to cause the machinery breakdown unacceptable condition 4 2 2 ISO 10816 2 standard This standard is used to evaluate the vibrations of turbo generators of the power greater than SOMW It differentiates the machinery in function of the rotational soeed The evaluation of the machine condition is based on the measurement of the RMS value of the vibrations velocity Rotational speed Category 1500 1800 3000 3600 boundaries 4 2 3 ISO 10816 3 standard This more detailed standard is designed for the condition evaluation of machines motors and pumps It is important to pay attention that for the machinery rotating at soeeds greater than 600 rpm the measurements should be done in the frequency range from 10Hz 1000Hz while for those rotating at soeeds between 120 and 600 rpm the frequency range should be from 2Hz 1000Hz The machine classification accordingly to this standard is shown in the following table Group Description S Big machinery power from 300kW to 50MW and electrical motors with shaft height H gt 315mm Middle size machinery power from 15kW to 300kW and electrical motors with shaft height 160mm lt H lt 315mm 3 Pumps with multi blade wheels with separate power transmission centrifugal with mixt or axial flow with the nominal power gt
7. 15kW Pumps with multi blade wheels with integrated power transmission centrifugal with mixt or axial flow with the nominal power gt 15kW The following table shows the authorized values at the category boundaries The standard additionally classifies the machines into those that are installed rigidly or flexibly DIAMOND 401 60 User s guide oundations boundaries RMS RMS 22 Foundations Category F rigid 45 CD 71 90 45 71 flexible BC 71 90 45 10 56 4 2 4 ISO 10816 4 standard It concerns the machinery assemblies driven by gas turbines at rotational speeds between 3000 rpm and 20000 rpm Only the vibrations velocity is taken into consideration Category boundaries mm s RMS GD 60 4 3 Bearings The parts which get worn fastest and which are most exposed to failures are the bearings The defects of balls or rollers and of bearing external or inner tracks become the sources of high frequency vibration pulses These pulses are not visible in vibration velocity or displacement signals that are measured in the frequency range 10Hz 1000Hz The vibration velocity or displacement signals are very useful for evaluation of the overall dynamic condition of a machine but do not contain any information about the bearings condition The information concerning the bearings is found in the vibration acceleration signal 4 3 1 Measurements of shock pulses The periodic measurements of the accelerat
8. Back and Next we move the arrows from one plane to another In the case of instrument version D and having selected two channels the arrows will indicate both planes We launch and stop the measurement If we use only one channel then we do the measurement with the button on one plane and afterwards by selecting Next we move to the other channe on which we repeat the measurement Once the preliminary measurements on both planes are completed we move on to the edtion of the test mass for the plane 1 Balancer ZF Test moss edit mt F1 200 Bock Hest Setup We do it in a similar way as in the case of the one plane balancing and after installing this mass on the plane 1 of the rotor we do the measurement Balancer ZF Test run with test mass on F1 Fid mt P2 4 28 SC 4 34 15417 2946 8rrm fd Back Hest Setup Next we remove the test mass from the plane 1 and we move on to the edition of the test mass for the plane 2 and we install it on this plane Balancer ZF Test moss edit mtr Fz 0 Di Bock Hest Setup We do the measurement with this mass installed DIAMOND 401 35 User s guide Balancer ZF Test run with test moss on Pe emt Fe h TE rans i DA 412 2352 rem SH Bock Hest Setup Once the measurements are completed we can read the first results The correction masses m0 are indicated separately for the two planes m0 P1 et m0 P2 Boloncer ZF Result correction mass
9. be erased if we choose Return Finally if we have decided to erase something by selecting YES or NO then we still have to answer the following question Memory Setur Contirm erasing YES H Return By selecting YES we erase the memory By choosing NO or Return we can still safely withdraw from this operation 2 12 3 Designating the measurement types in the memory DIAMOND 401 43 User s guide In the memory each measurement has its concise description These descriptions are displayed on the screen both with regular and route memories Here is the scheme that is used for the measurement descriptions TOT A 10 1k Field 1 three letters description of Field 3 description of the filter or the the type of the measurement frequency range TOT global level vibrometer BRG bearings verification FFT frequency analysis Field 2 A acceleration V velocity D displacement V D velocity with displacement BAL balancing SPD rotational speed TMP temperature CAV cavitation PHI phase ENV envelope IMP pulses KRT kurtosis E envelope for FFT 1 one plane balancing 2 two plane balancing Example Hemort regular Machine Pointmo 00141 01 fi TOT W 10 1k TOT O 10 1k ERC IMF IE ZE FFT u 1 6kHe Exit Delete SAUE 2 12 4 Formatting the memory A This operation will erase the whole memory and as a result all information contained in the m
10. changes cyclically during the measurement and then there is the place for the overload indicator streak of lightning To the left of the second line are displayed the measurement units and to the right the selected frequency band Below in place where will be shown the measurement results are displayed horizontal lines At the bottom of the display are shown three functions that may be selected with the keys Exit return to the main menu Evaluation selecting this function will get you to the machine condition evaluation based on ISO 10816 standards Setup opening the menu that will allow you to set up the vibrometer 2 3 1 Setting up the vibrometer By pressing the key underneath the function Setup we enter the menu where we can adjust the settings of the vibration level meter The following display appears Meter SetuP Type H Bond filter J Hz 1UkHz Fange A ms Averaging s z Return We can now adjust the following parameters Type quantity being measured Band filter frequency bands Range measurement range Averaging duration of averaging To navigate inside the menu we use the keys and WAAT The selected parameter is singled out To change the value of a parameter we use the keys and the value of the parameter is a number like for example the duration of averaging a number in the range from 1 to 60 then the change takes place in steps of 1 The alternative way of
11. have the access to the rotor how it is possible for example in fans DIAMOND 401 25 User s guide The balancing is done in several steps first we must evaluate the mass distribution on the rotor and then to correct this distribution by adding or removing some mass at specific locations in order to obtain the desired residual unbalance or the satisfactory level of vibrations Most often the balancing is done in one or two planes When the length of the rotor compared to its diameter is small then one plane balancing will do the job but for rotors of bigger dimensions two plane balancing is necessary The steps for one plane balancing START Installation of an accelerometer close to a bearing placing the marker on the rotor and installation of the tachometer Preliminary measurement of vibrations and phase Placing the test weight Measurement of vibrations and phase with the test weight mp Interpreting the result correction m0 dismantling the test weight and mounting the correction mass Measurement verifying the effect of the correction mass m0 Interpreting the result installation of the correction mass m1 Measurement verifying the effect of the correction mass m We continue this procedure as long as we get the satisfactory level of vibrations or of the residual unbalance The steps for two plane balancing START marker on the rotor and installation of the tachometer Placing the test weight on the first plan
12. or recommended by the manufacturer DIAMOND 401 69 User s guide
13. put the transducers on the machinery elements between which could appear the difference of electric potential 3 While making the vibration measurements on the rotating machinery one should avoid that the cables the valise straps etc get snatched by the rotary parts One should also respect the security recommendations related to the machinery 4 Do not get the magnets near the devices that are sensitive to the magnetic field like for example the computer disks the audio and the video tapes the magnetic cards etc 5 Do not use the instrument in the area where there is a danger of explosion 6 The vibration transducer should be fixed firmly to the machine Otherwise the measurement results may be affected by additional errors 7 Do not use the alcohol or other solvents to clean the instrument Protect the transducer and its magnet against the shocks 9 Do not place the instrument in places where the temperature may exceed 50 C 10 In spite of its robust construction designed for severe industrial environments one should avoid to use and to store the instrument while the humidity exceeds 95 11 This portable industrial instrument should be used by trained and or experienced personnel 12 If the instrument is out of order it should be returned to the vendor Repairing the instrument oneself implies the loss of warranty 13 Are authorized only those accessories like power supply cables etc that were provided
14. 0 P2 Interpreting the results corrections m1 P1 et m1 P2 separately for the first and the second plane and mounting the correction masses on their respective planes Measurement to verify the effect of the correction masses m1 P1 et m1 P2 DIAMOND 401 67 User s guide One continues the procedure as long as the vibration level or the residual unbalance are reduced to the acceptable level 4 7 4 Choosing the test mass The purpose of installing the test mass is to obtain a clear and measurable change of the unbalance his is necessary to establish the value and the location of the corrective masses The test mass should neither be too small the change of unbalance may not be visible nor too big since this could provoke very strong vibrations and damage the machine Typically we consider that the test mass is adequate if the centrifugal force resulting from its installation is approximately equal to the 1 10 of the rotors weight The following formula may be helpful in finding the right value of the test mass m the test mass Mw the mass of the rotor n the rotational speed in rpm fp the radius in cm at which will be installed the test mass DIAMOND 401 68 User s guide Important precautionary measures to be taken while using the DIAMOND 401 1 Do not put the accelerometers on the machinery elements where could appear a dangerous voltage 2 When using two measurement channels it is not allowed to
15. 01 53 User s guide A It is not recommended to shorten or to interrupt the charging by disconnecting the external power supply Neither it is recommended to start charging while the battery is not completely discharged By not respecting these recommendations we may provoke a partial loss of the battery capacity or even damage it 2 13 7 Accelerometers This option will provide us with the information concerning the accelerometers that are intended to be used with the instrument and choose the one for standard usage there is a different procedure concerning the transducers that will be used for balancing It is possible to introduce the information concerning four transducers which are designated Sensor 1 Sensor 2 Sensor 3 et Sensor 4 This information should be introduced in the factory if the instrument is shipped together with accelerometers or by the user if its him who installs the transducers A PC program used for calibration will help him to do so The information concerning each transducer should contain the following the type of accelerometer its serial number and its sensitivity After having selected this option we get the following message OF tion sensor dw BEZNE Ir Gz THOT SH S256 Details Return In this example two transducers were introduced The transducer number 1 was chosen for standard measurements what is indicated by the symbol v To select the transducer we Vv and M7 and to confirm it as
16. 6 46 Exit Setup Bearing kurtosis 15kH2 SUkHz 14 Beoring Envelope ae Hz 400Hz Al rm ze P k 14 6 34 2 Exit Setup On the first line immediately after the word Bearing is listed the quantity being currently measured and on the second line the frequency range Below on the left side is displayed the average value in the middle the measurement units and on the right the peak value The display for kurtosis is different since it is a dimensionless value 2 4 1 Settings for measurements on bearings To enter into the menu that will allow us to setup the measurement we should press the key just below the word Setup The example of a display is shown below DIAMOND 401 17 User s guide Bearing Setu THF e ImFoct Pulses Filter 1O0kH2 30kKH2 Fange AUTO Hveraging z Return The selection of various parameters is done in a similar way as in the preceding chapter The table below summarizes the possible choices quantity Measurement ranges frequency bands duration Impact pulses 5 50 500 m s2 AUTO 10 kHz 30 kHz 5 kHz 10 kHz Kurtosis 5 50 500 m s2 AUTO 10 kHz 20 kHz 1 60 sec 15 kHz 30 kHz 5 Hz 100 Hz Envelope 5 50 500 m s2 AUTO 50 Hz 1 kHz 1 60 sec 500 Hz 10 kHz 5 kHz 30 kHz Explanations Impact pulses measurement of impact pulses that are generated by bearings This measurement is done in the frequency range corresponding to the resonance
17. DIAMOND 401 User s guide MBJ Electronics s c ul Tulipanowa 21 30 432 Krak w Poland MBJ electronics s c shall not be liable for errors contained herein or for incidental or conseguential damages in connection with the furnishing performance or use of this material User s guide version D401 I 1 0 2004 No part of this document may be photocopied or reproduced and given to a third party without the prior written consent of MBJ electronics s c It is recommended to read the manual prior to using the instrument DIAMOND 401 2 User s guide Contents 1 Description of Diamond 401 1 1 Front panel 1 2 Connectors 1 2 1 S1 connector 1 2 2 S2 connector 1 2 3 Power supply socket 1 2 4 Connecting cables 1 3 Carrying case 2 Operating the Diamond 401 2 1 Power supply 2 2 Main menu 2 3 Vibration level meter 2 3 1 Setting up the vibrometer 2 3 2 Evaluation of machine condition accordingly to standards 2 4 Bearings 2 4 1 Settings for measurements on bearings 2 5 Phase measurements versions D and DT 2 5 1 Settings for phase measurements 2 6 Rotating speed measurements versions D and DT 2 6 1 Settings for speed measurements 2 7 Temperature versions ST and DT 2 8 Cavitation 2 8 1 Settings for cavitation measurements 2 9 FFT analysis 2 9 1 FFT analyzer setiings 2 9 2 Running the FFT analysis 2 10 Balancing versions D and DT 2 10 1 Balancer settings 2 10 2 One plane balancing 2 10 3 Two plane balancing 2 11 Meas
18. ace the corrective mass we can set 1 or 2 but we can select 2 only if the No of planes is also set to 2 If for two plane balancing we select 1 channel then we do the measurements in one plane after another while if we select 2 channels then the measurements in both planes are made simultaneously Ealancer SeTur a InFut for IP H Sensor oai InFut far ZF Fl sensor PT BZ TAO SH 18286 Return active input for one plane balancing We can choose A or B description of the transducer that will be connected to the channel selected above input that will be associated with the plane 1 in two plane balancing The choice is between A and B description of the transducer that will be connected to the channel selected above 28 User s guide Ealancer SETUP InPut for 2P P2 E Senzor P2 627A SHAB2BE Return Input for 2P P2 input that will be associated with the plane 2 in two plane balancing The choice is between A and B Sensor P2 description of the transducer that will be connected to the channel selected above A In the case when we do the two plane balancing and we choose the number of channels equal to 2 then if we have associated the input A with plane 1 the input B will be automatically assigned to the plane 2 and vice versa A The cable with a branching for two transducers is specially designed for the balancing and furnished with the instrument The cable with the green
19. ake sure that during the transmission there won t be a problem with the power supply If the batteries are low then during the transmission one should use the external power supply The external power supply should be connected to the instrument only after the connection with RS232 is made Once the transmission is over then we first disconnect the external power supply and only afterwards we disconnect the RS232 cable This sequence is important to avoid any damage to the RS232 link 2 13 2 Contrast This option allows us to optimize the contrast of the display The range of the adjustment is between 0 and 100 The contrast of the LCD display is sensitive to the ambient temperature and therefore it is very useful to have this possibility when the working environment is changed quite often The screen for changing the contrast looks like this OPTIKY Contrast oto Return located underneath the respective We make the adjustments by pressing the arrows signs lt 4 or gt A The contrast adjustment is memorized So if the last adjustment before switching the instrument off was so weak that we see nothing on the screen then when we turn the instrument on we won t see anything again This is a problem since we wont be able to change the adjustment of the contrast in order to recover the information being displayed on the screen Thats why there is a protection to avoid such a situation while turning the instrument on one s
20. ally the repairs were done either once the machine was broken or preventively but often unnecessarily at a fixed periods of time Both methods are economically unjustified The diagnostic based on the vibration measurements allows us to rationalize the machinery management since a given machine is taken for a repair only when its condition it requires The advantages are numerous Extension of periods between the repairs better productivity of machinery reduced cost of repairs Elimination of unexpected breakdowns it is possible to predict that the breakdown may happen Reduction of the maintenance costs the repair is much more expensive once the breakdown occurred A repair that was planned takes less time than a repair after the accident 4 1 3 Vibration measurements Where to measure Most often the vibration measurements are carried out on these parts of a machine which are most heavily exposed to the mechanical forces Principally these are the enclosures of bearings which are easily accessible from outside The transducers are fixed in the plane that is perpendicular to the axis of the rotor radial vibrations and in the direction of this axis axial vibrations The parameters to be measured The parameters that best reflect the dynamic condition of a machine and which are most often used are the RMS value of the displacement and of the vibration velocity These two parameters allow us to observe the beginnings of un
21. ample A for acceleration To display the result of analysis once the measurement is completed one should press the arrow underneath the word Spectrum By selecting Setup we can adjust the measurement parameters which are more numerous than in previous functions 2 9 1 FFT analyzer settings The following three screens show the parameters that may be setup for the FFT analysis DIAMOND 401 21 User s guide FFT Analyzer Setue THF e Frequency range Ho of lines EnveloPe filter Hz 400 Hz Return JUL rmy ze JE rms Ho of averages 494 Return FFT Analizer SetuP Hanning relative Ho of lines lt Ya J tull ronse otf Return As we can see there are 9 parameters that may be setup the last two do not concern the analysis but the display of the results The table below shows the parameters that are different for different quantities umn pecesia TE mom e Quantity Description filter Frequency ranges P K A Acceleration X 100 Hz 200 Hz 400 Hz 5 50 500 m s2 AUTO V Velocity og 800 Hz 1 6 kHz 3 2 kHz 5 50 500 mm s AUTO D Displacement X 6 4kHz 12 8kHz 25 6kHz 50 500 5000 um AUTO sie oe Hz 100 Hz Envelope 50 Hz 1 kHz Hz 1 kHz 100Hz 200Hz 1 6kHz 5 50 500 m s2 AUTO 500Hz 10kHz 100Hz 200Hz 12 8kHz 5 kHz 30 kHz 100Hz 200Hz 25 3kHz The next table shows the parameters that are the common to all the auantities Possi
22. balance and of misalignment the bending and the deformations of machine elements the growing play in its structure That s why various standards that were established to evaluate the machinery condition are based on the measurements of these parameters The separate but related issue are the measurements of parameters allowing us to verify the condition of bearings DIAMOND 401 58 User s guide The periodicity of measurements The time between two consecutive measurements depends on the type of a machine Machines having shorter life time should be verified more often than those having longer life time If the vibration level of a given machine remains unchanged then the measurements can be carried out less frequently On the contrary when growing vibration level is noticed then the measurements should be done more frequently What is essential is to identify the moment when the vibration level begins to change On average the vibration measurements are carried out about 10 times during the period between two consecutive revisions 4 2 Standards In order to facilitate the diagnostic about the condition of a machine various standards were elaborated The most popular are the family of international standards ISO 10816 where each one is destined for a specific type of machinery The following paragraphs explain how to apply these standards to the machinery condition verification 4 2 1 ISO 10816 1 standard This is a general standard which
23. ble choices Number of spectral lines 100 200 400 800 1600 Zoom O Zoom 1 2 4 8 16 1 84816 ooo Averaging type RMS P K OFF Number of spectra 1 999 Rectangular Hanning Explanations Envelope filter corresponds to the frequency band that is chosen only for envelope analysis accordingly to rules that are applicable for DIAMOND 401 22 User s guide Freguency range Number of spectral lines Zoom Averaging type Window bearing condition evaluation the analysis is done between O Hz and the selected freguency this parameter defines the number of spectral lines that are calculated within the previously selected freguency range The ratio of frequency range to the number of spectral lines defines the spectral resolution this capability allows us to increase the spectral resolution around a given frequency This frequency is picked up with a cursor and the whole number of spectral lines previously selected will be calculated in the frequency range that is narrower by a selected zoom factor concerns the procedure that is applied to calculate the average spectrum from the spectral lines measured consecutively The RMS averaging gives the result which is the square root of the sum of squares of lines entering into calculation Number of spectra The P K averaging registers the max values of all lines being averaged this function is used to improve the quality of the spectral estimation by reduc
24. ces he measurement is not instantaneous and one should wait a while until the display gets stabilized The K type thermocouple converter included with the set should be used to connect the sensor to the instrument A During the measurement one should avoid to move the sensor around the surface since it may get damaged The surface being measured should be flat and clean The measurement range is up to 250 C 3 2 Cables The instrument is provided with high quality cabling made of cables of great elasticity The connectors should be kept clean to insure the good operation The instrument sockets have different colors The sockets for accelerometers are marked with the green color while the socket for the temperature and the rotational speed sensors is designated with red color The corresponding connectors on the cables are identified with the same colors The cable for accelerometers has the color identifiers also on the transducer side the green connector jacket indicates that the corresponding transducer connects to the channel A the blue jacket indicates the channel B A All vibration measurements are made on channel A The channel B is used only for balancing 3 3 External power supply DIAMOND 401 is provided with the external power supply which is also used for charging the battery It is a typical stabilized supply 9 V DC and 1200 mA The positive end is inside the socket the negative end is outside A Attention Don t op
25. d Its color is green in normal operation and red while the batteries are being charged When the batteries are almost discharged then in the upper right corner of the display appears the icon symbolizing a battery Moin menu 4 DIAMOND 40 Signalization that the batteries are discharged One should then connect the external power supply and in the Option menu turn the charging on This is confirmed by changing the color of the diode from green to red The charging is controlled by the instrument and after about 4 to 5 hours it is turned off and the diode returns to the green color You will find more information in the paragraph concerning the options A At the beginning of charging the diode changes its color from green to red The batteries should be charged without interruption until the diode returns to the green color what typically takes place after 4 to 5 hours It is not recommended to shorten the duration of charging or to charge by fits and starts or to start charging when the batteries are not discharged completely This may reduce the capacity of accumulators or even they may get damaged 2 2 Main menu The key 4 is used to switch the instrument on and off When the instrument is switched on the display comes on and the main menu appears The three keys and the key are used to navigate throughout the menu On the bottom of the display and above the keys A are displayed the icons representing various func
26. distance of 10 cm to 100 cm from the surface of the rotor on which a reflective strip is stuck The Class 2 semiconductor laser generates the light beam 650 nm The sensor is installed on the adjustable support which allows us to direct the laser beam in the desired direction All this is attached to the machine with the magnetic holder The location where the transducer is attached should be selected in such a way that during the measurement it does not change its position with respect to the rotor The laser beam should be directed towards the reflective strip A For the phase measurements and for balancing the boundary where the beam goes from the dark part of the rotor onto the reflective strip is considered to be the reference point The angle increases in the direction opposite to the rotation A The laser beam sensor should be protected against the humidity and the dust The mechanical shocks should also be avoided and the ambient temperature should not exceed 40 C A For safety reasons it is not allowed to look directly into the aperture of the laser beam One should not direct the laser beam towards the sparkling surfaces nor in the direction of other people Avoid getting the beam directly or indirectly into your eyes DIAMOND 401 56 User s guide 3 1 3 Temperature sensor The K type thermocouple is used for the temperature measurements It has weak thermal capacity and is well suited for the temperature measurements of flat surfa
27. distribution of the mass of the rotor and then on correcting this distribution by adding or removing a mass in order to obtain the residual unbalance or an acceptable level of vibrations In most cases the balancing is performed in one or two planes 4 7 1 One plane balancing The balancing in one plane is applicable when the width of the rotor is small compared to its diameter This is illustrated in the following drawing DIAMOND 401 65 User s guide b D NO YES pm gt 1000 10000 This next drawing gives an example where one plane balancing is applicable S1 indicates the point where the measurement is carried out P1 indicates the plane where are applied the corrective masses The steps in one plane balancing START Installation of an accelerometer close to a bearing placing the marker on the rotor and installation of the tachometer Preliminary measurement of vibrations and phase Placing the test weight Measurement of vibrations and phase with the test weight mp Interpreting the result correction mO dismantling the test weight and mounting the correction mass Measurement verifying the effect of the correction mass m0 Interpreting the result installation of the correction mass m1 Measurement verifying the effect of the correction mass m DIAMOND 401 66 User s guide One continues the procedure as long as the vibra
28. down into the authorized components we press the button and the functions above the arrow keys change and we get the following display Balan er 1F Result correction mass mu 130 343 zPlit By selecting Split we get a display on which the calculated location is broken down into two locations where we can now place the corrective masses In this example these locations are at 300 and 360 Balancer IF Correction moss zFlit mi 343 1505 m 1 3007 43 04 m 2 360 10338 Return ZETUP By selecting Return we quit this procedure and return to the measurement We do a new measurement with the correction mass mO installed by pressing DIAMOND 401 32 User s guide Balancer 1P Check run with corr mass mu 1 T mms E 243 zde 2 FF Back Hest Setup We notice that once the correction mass mO installed the vibration component is six times smaller than during the preliminary measurement This improvement was obtained after the first step in the balancing procedure To continue we press Next and we get the correction mass m1 Balan er 1F Result correction mass md 22 23 1007 Bock Hest Setup As we can see this mass is already significantly smaller than m0 and step by step we get closer to the situation when the rotor is perfectly balanced Let us assume that we are already satisfied and in this case we would consider the mass m1 as the residual unbalance But lets cont
29. e Vieasuring vibrations and phase on both planes with test weight mp on the first plane Dismantling the test weight from the first plane and its installation on the second plane Measuring vibrations and phase on both planes with test weight mp on the second plane DIAMOND 401 26 User s guide Interpreting the results corrections m0 P1 et m0 P2 separately for the first and the second plane dismantling the test weight and mounting the correction masses on their respective planes Measurement to verify the effect of the correction masses m0 P1 et m0 P2 Interpreting the results corrections m1 P1 et m1 P2 separately for the first and the second plane and mounting the correction masses on their respective planes Measurement to verify the effect of the correction masses m1 P1 et m1 P2 We continue this procedure as long as we get the satisfactory level of vibrations or of the residual unbalance 2 10 1 Balancer settings By choosing in the main menu the symbol of a balance we enter the balancing function As usual first we have to adjust the settings and therefore we enter the setup menu Ealancer ZeTuF Ho of planes 1 Ture U Tracking filter 0 05 Hz Range Auto Return Explanations No of planes we choose one plane or two plane balancing the choice is 1 or 2 Type defines the vibration quantity that will be measured during the balancing In the case of DIAMOND it is fixed and it is the velocity
30. easurement we press the START STOP button DIAMOND first activates the tachometer mesures the rotational speed and then starts to measure the amplitude and the phase of vibrations at a given rotational frequency As soon as we see that the displayed results have stabilized we can stop the measurement by pressing the MENAN button DIAMOND 401 30 User s guide A The time necessary for the result to stabilize on the display depends on the choice of the Tracking filter If we have chosen the 0 5 Hz filter then this time is about 4 seconds while for the 0 05 Hz filier we must wait about 40 seconds The last result remains displayed on the screen To pass to the next step that is the edition of the test mass we press the arrow below Next Balancer IP Test mass edit mt 200 s n Back Hest Setup The weight and the angular position of the test mass are displayed on the screen In order to start the editing one should press the button pa It is possible to edit three digits the position of the decimal point and the measurement unit The selection of the consecutive elements for the edition is made with the horizontal arrows lt and gt while the change of digits of the position of the decimal point and of units is obtained with the vertical arrows and h To confirm the value of the mass that we have edited we press the button and automatically we pass to the edition of the angular position As previ
31. ement is finished the symbol does not move any more 2 3 2 Evaluation of machine condition accordingly to standards In order to evaluate the machine condition one should pick on with the key the Evaluation function The following information will be displayed on the screen Meter Evaluation Standard Evol Grour 1 I5U 1U S1E 3 inadmissible SUPPOFT unsotistoctor Flic uccePtoble Jool standard Grouf Return The Standard function allows you to choose among the ISO 10816 standards the one corresponding to your machine If a given standard classifies the machines into groups then the Group function allows you to select the corresponding group The table below summarizes the available standards Additional classification IS010816 1 e S O ISO 10816 3 Flexible support E ISO 10816 4 By choosing Return we quit the Evaluation function In order to return to the main menu we should press the key DIAMOND 401 16 User s guide 2 4 Bearings In order to do the measurements that will allow us to evaluate the condition of bearings we must open the corresponding menu by selecting in the main menu with the key the symbol of a bearing With DIAMOND the condition of a bearing is estimated using several methods that are based on the analysis of impact pulses envelope and kurtosis The menus corresponding to these different methods are shown below Bearing ImPoact Pulses 10kHz SUkHz LIG dE F K 1
32. emory will be lost In order to format the memory one should open the memory menu by pressing w DIAMOND 401 44 User s guide Memory Setup TYP e of memory Hemort free Erose THFE Return Next with the help of the key we change the functions that are displayed at the bottom of the screen in order to get the access to the function Format Hemort Setup TYP e of memory Hemort free Format THF E Return We select this function with the key and the following message and question are displayed Memory Setur Hemort formatting Hemort will erqze Cantinue Anwsering YES requires still the confirmation Hemort Setur Confirm torma tins TES H Return At this point the formatting begins and during the formatting the following message is displayed DIAMOND 401 45 User s guide Memory formatting at The formatting lasts about one minute A You should make sure that during the formatting the power supply of the instrument is working properly If the batteries are weak then the formatting Is not possible It is recommended to do the formatting with external power supply which should remain connected the whole time It is not allowed to switch off the instrument during the formatting and for this reason the button is disabled while formatting is in process 2 12 5 Memory messages The following message will appear if during the recording the memory is full Memory ful
33. en the power supply in operation and don t connect it when it is wet The power supply is turned on at the same moment it is plugged into the mains what is signalled by a diode located on its housing DIAMOND 401 57 User s guide 4 Theory 4 1 Vibration measurements and machine condition evaluation 4 1 1 Machinery vibrations A side effect of any operating machine is the energy emission in the form of vibrations A correctly constructed machine and in a good condition exhibits a low level of vibrations During the exploitation different parts of a machine wear out suffer the abrasion and deformation its foundations settle As a result the play between different parts increases the rotating elements get unbalanced and rotors misaligned All these factors provoke that as the condition of a machine deteriorates more and more energy is dissipated in the form of vibrations This close relationship between the condition of a machine and its level of vibrations is the justification for using the vibration measurements for machinery diagnostics 4 1 2 Inspections and maintenance The fundamental rule of the machinery diagnostics based on vibration measurements is that these measurements should be carried out systematically The periodical measurements will allow us to observe the evaluation of the vibration levels with time and thus the deterioration of the machine condition This is essential for a good management of machinery maintenance Tradition
34. ent YES H Return By choosing NO or Return we return to the memory mode If we have chosen YES then we have to confirm Hemort route Lantirrn FePetition YES H Return The last chance to avoid the replacement of the recorded measurement by a new one is by selecting either NO or Return By choosing YES we launch the new measurement As usual to stop the measurement we press AI Once the measurement is ESC completed we return to the memory mode by selecting Exit or by pressing sc At this point the old measurement result is replaced by the new one 2 12 2 6 Erasing the route memory In the case of route memory one should first erase the recorded measurements and only afterwards it is possible to erase the route To do that we need to enter into the memory settings and select Type of memory route DIAMOND 401 42 User s guide Memory Setup TYPe of memory Memory free Erose THFE Return Next using the arrow A we select Erase The question will appear Hemort Setup Erose measurements trom route 7 TES H Return By choosing YES we get ready to erase the measurements or the measurements together with the route in order to avoid this we should choose No or Return Hemort Setur Erase route YES H Return Now we have three choices by choosing YES we erase the measurements and the route if we have chosen NO then only the measurement results will be erased and nothing will
35. eria that are applicable in typical cases In order to raise the certainty of the evaluation it is recommended to use at least two of these methods or to check empirically which of these methods is the most reliable DIAMOND 401 62 User s guide A The diagnostic measurements on bearings should always be done using the same accelerometer Some of the measurements are sensitive to the characteristics of the transducer the resonance frequency the resonance quality factor and therefore different transducers may give different results 4 4 Spectral analysis of vibrations The progressive increase of the vibrations level tells us that the dynamic condition of a machine deteriorates The measurements of the overall level of vibrations vibration velocity or displacement allow us to evaluate the current condition of a machine and to monitor its evolution However these measurements do not contain the information concerning the source of the deterioration We can obtain this information with the spectral analysis Each part of a machine or a defect generates the vibrations of a characteristic frequency or several characteristic frequencies as it shown in the Figure below he spectral analysis allows us to identify the elements that have caused the problem Vibration Frequency Hz This drawing illustrates the relationship between the condition of vari
36. ers is the following Measured quantity Frequency band Averaging duration 2 Hz 1 kHz 10 Hz 1 kHz 100 Hz 1 kHz 1 kHz 10 kHz Explanations Averaging duration it is the record length in seconds that is used to calculate the results For example if the selected averaging duration is 5 sec then the RMS values are calculated on the block of data corresponding to this duration while the P K and P P values represented the maxima during the last 5 seconds The results are updated every 0 5 sec but the first result will be displayed after 5 sec It is possible to select a different averaging duration for each filter and these setiings are memorized DIAMOND 401 15 User s guide Once we are done with the settings we can quit by selecting Return with the corresponding key We are now ready to start the measurement by pressing the START STOP key The horizontal lines begin to flash The instrument picks up the selected measurement range or if AUTO was programmed then it searches the adequate range starts the measurement and displays the result on the screen The first result will appear after the time corresponding to the selected Averaging duration and is updated every 0 5 sec To stop the measurement we press again the START STOP key The last result remains displayed on the screen A The execution of the measurement is indicated by the symbol in the upper right corner that is changing cyclically Once the measur
37. frequency of accelerometer The result is given in dB Envelope measurement of the acceleration envelope which contains the information about the state of a bearing The frequency band should be selected in such a way that the lower frequency is greater than 10 x rom 60 Rotational speed of the machine 5 Hz 100 Hz lt 300 rpm 50 Hz 1 kHz lt 3000 rpm 500 Hz 10 kHz lt 30000 rom 5 kHz 30 kHz Kurtosis this dimensionless parameter indicates the impulsive content of the measured signal The frequency band i e the filter should be selected experimentally for each case To quit the settings and return to the main menu press the arrow key underneath the word Return Starting and stopping the measurement is done similarly as in the previous chapter on vibration level meter DIAMOND 401 18 User s guide 2 5 Phase measurements versions D and DT It is possible with DIAMOND 401 to measure simultaneously the phase of the first and the second harmonic of the rotational frequency as well as the rotational soeed Obviously to achieve that one should use in addition to an accelerometer also the sensor measuring the rotational soeed We access the phase measurement function by selecting from the main menu the corresponding symbol The screen looks then like this Prose l Harra 1 Horm 2 3 34 2 56 2807 2887 3 2359 Exit Setup The quantity being measured is displayed in the first line just after the wo
38. gative we should contact the factory v To quit this option we select Return or press 3 Accessories 3 1 Transducers DIAMOND 401 55 User s guide DIAMOND 401 being a multifunction instrument reguires several types of transducers Hereafter there is some information concerning these transducers 3 1 1 Accelerometers DIAMOND 401 requires IEPE ICP accelerometers The recommended accelerometers are 786A from Wilcoxon or M622A01 and M623A01 from PCB The user can choose other IEPE accelerometers but he should first verify whether they satisfy the requirements of DIAMOND 401 The magnetic mounting adapters are used to attach the accelerometer to a machine Attention should be paid that the surface between the transducer and the magnetic adapter is clean and that the transducer adheres well to the surface of the magnet In particular strong magnets may attract ferromagnetic rubbish which should be removed Also the magnetic adapter should adhere well to the surface of the machine All this is very important since it may influence the accuracy of the measurement The accelerometers should be protected against the shocks for example by falling on hard surfaces 3 1 2 Rotational speed measurement sensor For rotational soeed measurements the DIAMOND models 401D and 401DT are equipped with the laser tachometer It is also used as reference sensor for phase measurements and for balancing The laser tachometer should be installed in a
39. he planes corresponding to two bearings preferably at opposite ends of the rotor Before starting the balancing one should select No of planes 2 l we have at our disposal only one accelerometer then we will have to move it from one plane to another On the other hand if we have two transducers then we can fix them and we won t be obliged to move them around This reduces the risk of committing errors shortens the time necessary to complete the balancing and renders the procedure easier to handle If in the settings we have selected the number of channels equal to one No of channels 1 then the measurements will be performed alternatively on one and another plane On the contrary if we have selected the number of channels equal to two then it will be possible to perform the measurements simultaneously on both planes It is important to assign each plane to one of the two channels and to have the related transducer installed on the corresponding plane The settings are adjusted in the same way as it was discribed in a previous paragraph Once we are done with the settings we get the following display Boloncer ZP i Balancing Hest Setup Selecting Next will get us to the preliminary measurement DIAMOND 401 34 User s guide m 752 VE 532 EE z LB ZE Clear Hest Setup If we have selected only one channel then the arrows and next to P1 or P2 indicate the plane that is currently chosen for the measurement With
40. hould keep the key depressed This will restore the normal value of contrast and we shall be able to work with the instrument again 2 13 3 Brightness This option allows us to regulate the luminosity of backlight of the display DIAMOND 401 50 User s guide OF tion Brightness KE n i Return The following choices are possible 0 33 66 100 0 means that the backlight is turned off Us for contrast the adjustment is made by pressing the arrows underneath 4 or gt A Using the backlight increases the consumption of the energy and it speeds up the discharging of batteries Therefore one should use the backlight only when it is really necessary 2 13 4 Time and date DIAMOND 401 is equipped with the real time clock which needs to be adjusted From Options menu we select the symbol of a clock and we get the following message OF tian Times Date set Time 24 42 Date 22 06 2005 Return To start the adjustment we press the key zn The first digit starts to blink To change it we use the M 14 To move to other digits for adjustment we use the To confirm the setting we press again zn To quit the we press E2 and to quit the time and date option adjustments without the modifications we select Return or we press again If we have tried to introduce erroneous data they won t be accepted by the instrument and we shall be obliged to do it again correctly 2 13 5 Power se
41. ilarly the axial vibrations of bearing bodies are of opposite phase if the rotor is bended 4 6 Cavitation The cavitation is the strongest source of noise and vibrations in liquids The cavitation originates when in a given temperature the pressure in the stream of liquid is lower than the pressure of its saturated vapours This phenomenon most often takes place in pipes for example in pumps in valves when the flow is swirling or turbulent It consists of the formation and extinction of bubbles of saturated vapours It is very harmful and provokes the cavitational erosion of machinery elements The vibration signal which is generated the cavitational noise has a large bandwidth from several kHz to several dozens of kHz and it can be superposed on other vibro acoustic phenomena like signals from bearings That s why in order to be able to measure the effects of cavitation one should locate the measurement point as far as possible from other elements which may affect the measurement like bearings If there is no cavitation then the vibration level should be of similar magnitude as the one produced by other sources but when the cavitation appears then this level increases significantly 4 7 Balancing The unbalance of the rotary elements of a machine is the main reason for the excessive vibration levels It manifests itself by a high level of radial vibrations at the rotational frequency The balancing consists on analyzing the
42. ing OF tion Battery chorging Last chorging eFFOF OFF OH Return The error can occur if the batteries are damaged or if Surrounding temperature was too high The problem during the charging is signalled at the end of charging by blinking of the red diode The selection of the battery charging option cancels this signalization To activate the charging we select ON to stop it OFF To optimize the usage of battery it is not recommended to interrupt the charging so the possibility to turn it off is there in case we have launched the charging by mistake When we connect the external power supply then the charging is indicated by the fact that the diode changes the color from green to red and we get the following message on the screen OF tion Battery Chor ding is OH OFF OH Return The charging takes from 4 to 5 hours If the charging went well then the diode returns to green color and if there was a problem then it will be blinking alternatively with red and green colors A We charge the battery only when the symbol on the screen indicates that the battery is weak We should let the charging fill the battery completely It is not recommended to interrupt the charging without any serious reason The instrument controls the charging and after 4 5 hours turns it off automatically This is indicated by the diode changing its color from red to green Only then we are allowed to disconnect the adapter DIAMOND 4
43. ing the so called leakage The effect of leakage is that the amplitudes are underestimated and the spectral energy is smeared into a broadened spectral lines The A cursor function helps to find the real values of 2 9 2 Running the FFT analysis Once we are done with the setup we can start the analysis by pressing the key START SJM The coordinates and the word wait appear on the screen After some time the first spectrum is displayed which is then refreshed continuously Here is an example of screen during the FFT analysis DIAMOND 401 23 User s guide Y axis range and measurement unit Symbol indicating that the measurement is running Portion of the spectrum that is disnlaved Functions attached to the arrow keys underneath the screen EU Hz A 54 0 ZAH Cursor Spectral amplitude indicated by cursor Value of A cursor At the bottom of the screen is shown the freguency corresponding to the position of the cursor on the X axis followed by the amplitude of the spectral line selected by the cursor and the value of the function A cursor Vertically below the sign indicating that the measurement is being executed is shown the Y axis range and measurement units further below is indicated schematically which portion of the entire spectrum is currently being displayed on the screen followed by three symbols which are currently linked to the three arrow keys below the screen and finally the X a
44. inue and in this case we should ask to break down this mass into several locations SO we press MENU and we get new functions at the bottom of the display Now we select Split Balan er 1F Result correction mass md 22 23 1007 SFlit The result appears on the next display Balancer IF Correction moss zFlit n AMW 22 23 mi i BU 3 60 mi 2 120 16 64 Return Se Tur Without removing the mass m0 we install at the indicated locations the mass m1 and in order to check the efficiency of this modification we repeat the measurement DIAMOND 401 33 User s guide Balancer 1P Check run with corr mass md 0 36 mms ete 5 2954 7 Pm Back Hest Setup We find out that compared to the previous result the installation of the correction mass m1 has reduced the vibrations by a factor of three and in total the installation of the m0 and m1 masses has reduced the vibration by a factor of almost 20 We could continue this process up to the correction mass m9 but in most cases it is not necessary and usually after two or three steps the results are entirely satisfactory The last correction mass that was calculated may be considered as the residual unbalance of the balancing procedure To quit the procedure we hit 2 10 3 Two plane balancing Two plane balancing is a dynamic balancing where one places correction masses on two planes Therefore it will be necessary to perform the measurements on t
45. ion pulses generated by a bearing allow us to detect a developing defect and to observe its evolution These measurements should be carried out systematically in order to monitor the deterioration of bearing condition he increase of the peak value P K of pulses with respect to their initial value when the bearing was in a good condition for example when it was new is the indication of the bearing condition at a given time This reference value the initial condition may be different for different machines and is related to the fact that some bearings are more enclosed weaker signal or less enclosed stronger signal some are less loaded weaker signal while some are more loaded stronger signal DIAMOND 401 61 User s guide The table below indicates the bearing condition in function of the increase in the pulses peak value with respect to the initial state Bearing condition A lt 20 dB GOOD 20 dB lt A lt 35 dB ATTENTION A gt 35 dB The increase of the peak value by 20 dB to 35 dB indicates that a flaw has appeared in the bearing The bearing should be now observed more carefully and the measurements carried out more frequently The increase greater than 35 dB attests that the bearing is seriously damaged and should be replaced In the situations where we are lacking the reference information concerning the initial condition then for the diagnostic purposes we can observe the difference between the peak and the mea
46. is used when a given machine does not fit the more specific standards It is based on vibration measurements and the machines are classified into four groups Group Description small machines including motors of power below 15kW 2 middle size machines and motors from 15 to 75kW without foundations and motors up to 300kW installed on foundations big machines and motors installed on rigid foundations 4 big machines and motors installed on flexible foundations In order to be able to use this standard one should measure the vibrations with the instrument having the possibility to measure the RMS value of the vibrations velocity within the recommended frequency range To evaluate the condition of a given machine one should compare the measurement results against the values indicated in the table below Table with the RMS values of vibration velocity authorized by the ISO 10816 1 standard Category pms RMS boundaries mm s RMS Depending on the results of vibration measurements the ISO 10816 standard classifies the working conditions of a machine into four categories A B C and D Hereafter the evaluation of machine condition for each category DIAMOND 401 59 User s guide A the vibrations of machinery recently introduced to operation good condition B machine which can work for a long time without limitations satisfactory condition C machine which cannot work continuously for a long time it can work for a predefined
47. ith each of these four versions ___Functionality Version S ST D DT Data collection X X X X popem et Phase meausrement Balancing Balancing kociaki l FX EE This user manual covers all four versions DIAMOND 401 6 User s guide 1 1 Front panel Keys to make the selections in the menu that is currently on displav Key for accessing the memory MENU START STOP Options key MEMORY s gt Pa POINT OPTIONS A Power ON OFF Diode signalling ESC external power supply and battery charging POWER CHARGING 1 2 Connectors Below is shown the localization of the connectors S2 connector rotational speed or temperature measurements RS232 connector communication with PC DIAMOND 401 7 Measuremet Start Stop key Cursor key Escape or return kev CR key S1 connector vibration measurements A and B inputs 9 VDC external power supply socket User s guide 1 2 1 S1 connector 1 not connected 2 Input A for vibration measurements 3 A input ground 4 B input ground o Input B only used for balancing 6 not connected 1 2 2 S2 connector 1 3 3 VDC power supply 2 RPM measurements pulses input 3 Digital ground 4 Analog ground 5 DC measurement input 6 DC measurement input 7 5 VDC power supply DIAMOND 401 8 User s guide 1 2 3 Power supply socket
48. l If we open the memory from the main menu or while executing the measurement but without any result to save then if we select Save we get the following message Hothin to save Another message will appear when we would try to write into the memory while the batteries are weak DIAMOND 401 46 User s guide Unsafe Power surely Writing inFozzible During the recording or erasing the following message is displayed Memory wrting Kat From time to time the memory needs to be refreshed and then the message shown below will appear This happens very rarely but when it happens then you should wait until it disappears Hemor refresh init In case of error the access to the memory is forbidden Error Memory inaccessible Finally if there is an error during the recording then the following message appears DIAMOND 401 47 User s guide Memor error Lrifinz imPossible 2 13 Options The remaining functions and settings are dealt with in the menu Option To access this menu you should press the button OPTIor menu The meaning of the symbols starting from the left is communication with PC adjusting the contrast and adjusting the backlight brightness of the display As usual we select the desired option with the corresponding A key In order to get the remaining functions that are available under Options we should press MENU Here are the two additional screens OPTI
49. lf release This option allows us to set the period of time after which the instrument will be switched off automatically This period is measured from the last time we have pressed any key It is the protection against discharging the batteries needlessly in case we have forgotten to switch off the instrument We have the choice between 15 30 45 60 minutes DIAMOND 401 51 User s guide OPTIKY Auto Power off After 30 min Return To disable this option we should select OF tion Auto Power off Disabled The selection is made with the arrows underneath the display 2 13 6 Battery charging Using this option we can initiate and stop the battery charging The color of the diode at the bottom of the front panel indicates whether battery is being charged or not the diode is red while battery is being charged and it is green when there is no charging We activate this option by selecting the battery symbol at the bottom of the Options menu DF tion Battery chorging Last chorsins Uk OFF OH Return At the center of the screen is displayed the message informing us what was the status of the last charging OK the previous charging went well OF tion Battery chorging Lost charging Uk OFF OH Return break the user has interrupted the charging DIAMOND 401 52 User s guide OF tion Battery chorging Lost charging break OFF OH Return error there was a problem during the charg
50. mark is destined for the input A while the one with the blue mark for channel B Once we have completed the setiings we press Return 2 10 2 One plane balancing lf we have selected one plane balancing No of planes 1 then the following screen appears after having pressed Return Bolar er IF i R alancinq la Hest Setup In order to continue you should press the arrow underneath the word Next Appears the first screen related to the preliminary measurement as shown on the following example DIAMOND 401 29 User s guide Balancer 1P Initial run G D8 mms 176 2945 3 Pm Clear Hest Setup If in the buffer memory remain the results from the previous balancing then they will be displayed on the screen We have now the possibility to either continue the previously started balancing or to start a new one To clean the results from the buffer memory one should select Clear and anwser the following question Balancer 1P Initial run Cleor balancina 7 TES HU SetuP If we have chosen YES then we are asked to confirm Balancer 1P Initial run Contirm clearing TES HU SetuP We will then get back the intitial screen with buffer memory erased A The whole balancing procedure consists of consecutive steps which are shown on the following screens In order to get to the next step we should select Next and should we need to return then we select Back In order to perform the preliminary m
51. measurement points available on this machine Using the same keys we can move the highlighted zone on the list of points By pressing again lt we unfold the branch of the selected point The reversed video will appear now on the list of measurements that should be performed in a given point To fold back the branches we use the key If the reverse video characters are on the list of measurements then by pressing the S02 key we launch the highlighted measurement To stop the measurement we press again the 300 key The instrument returns then to the memory mode records the measurement that was just executed and the sign v is placed in the list next to this measurement Afterwards the next measurement in the list is highlighted and we can launch it immediately by pressing RR 405 measurements for a given point what means that all the measurements for this point are done then this sign will appear also next to the name of this point We should press then When the sign v appears next to all and select the next measurement point If we have completed all measurements for all points of a given branch then the sign v will appear next to the name of the machine to which belong all these points In this case we can select another machine unfold the branch and again unfold the branch of the selected point and continue to collect the measurements Once we have completed all measurements of the route then the sign v will be di
52. memory the machines and the measurement points are designated by consecutive numbers A machine can have the number between 1 and 100 while the measurement points are numbered from 1 to 15 Therefore when working with the regular memory we can DIAMOND 401 37 User s guide distinguish up to 100 machines and on each machine 15 measurement points Here is how looks the display of a regular memory Hemort resulor Machine Foint no 00141 01 p Heasurement 1 Measurement 2 Measurement 3 Measurement 4 Exit il POINT To select the number of a given machine we use the keys s and P while to pick up the measurement point on the selected machine we use the keys A and Y 2 12 1 1 Measurements recording in the regular memory If once the measurement is completed and its result displayed on the screen we would like MEMORY to register it in the regular memory then we should first press the button and then using the respective keys we must enter the number of the machine and the number of the measurement point The recording is accomplished after pressing the key A underneath the word Save To return to measurements we should press either the key or select Exit with the key A i 2 12 1 2 Displaying and cancelling the measurements In order to visualize or to cancel the measurements that are recorded under the currently displayed number of the machine and the measurement point one should press the key
53. ment 4 3 3 Kurtosis 4 4 Spectral analysis of vibrations 4 5 Phase measurements 4 6 Cavitation 4 7 Balancing 4 7 1 One plane balancing 4 7 2 Two plane balancing 4 7 3 Choosing the test mass DIAMOND 401 5 User s guide 1 Description of Diamond 401 DIAMOND 401 is a modern measurement instrument designed for performing multiple tasks in the field of machinery monitoring the machine vibration measurements and analysis the evaluation of machine condition the verification of bearings condition the measurement of rotational speed and temperature the balancing of the rotating machinery the data collection allowing the user to register the measurements according to the predefined route The instrument case is made of aluminium what provides great mechanical resistance and good protection against the electro magnetic perturbations The IP65 protection level does not allow the humidity and the dust to penetrate inside the housing The connectors are easy to manipulate and insure reliable and lasting connections The LCD display with backlighting allows the instrument to be used even in the condition of poor visibility DIAMOND 401 is shipped together with the MBJLab software for post processing archiving and visualisation of the measurement results DIAMOND 401 is available in four versions allowing the customer to choose the version that best suits his application The following table summarizes the functionalities that are available w
54. n values This difference is less than 20 dB for bearings in good condition If it is between 20 dB and 30 dB it may indicate the appearance of a flaw and when it is more than 30 35 dB then the bearing is broken Higher values of both peak and mean values may indicate that the bearing lubrication is insufficient 4 3 2 Acceleration envelope measurement The proper frequency range selection is important for the envelope measurement It should be adjusted in function of the rotational speed of the machine The peak value of the envelope indicates a local deterioration while its mean value contains the information about the general condition of bearing and about its working environment like for example its lubrication The possibility of selecting the frequency range allows us to monitor the wear of a bearing for example for slow machines 4 3 3 Kurtosis The kurtosis is not informing us about the amplitude of the signal generated from within the bearing but about its waveform The value of the kurtosis coefficient is about 3 when the signal does not contain strong pulses But as soon as a flaw appears and the pulses grow in amplitude then the kurtosis value grows as well The kurtosis value for new bearings Is in the range 3 to 4 while for a bearing that is damaged its value may be from 10 to 20 and more A The diagnostic methods for bearings described above do not have a normative character They should be considered as indicative crit
55. nt result that is displayed on the screen may be affected by an error If the overload is temporary and disappears after a while then the lightning symbol will disappear as well and the measurement result is correct If the overload sign reappears quite often then we should increase the measurement range On the other hand if we have selected the range AUTO then the instrument will take care of this problem and will change the range automatically However if we have reached the highest measurement range and we still have the overload condition then it means that the signal exceeds the measurement range of the instrument This is a rare case which may happen with some high speed machines in which the bearings or transmissions are out of order If such is the case then the solution consists in replacing the accelerometer with another one 10 times less sensitive 2 12 Memory management DIAMOND 401 is equipped with the Flash memory for recording and storage of measurement results There are two ways of using this memory depending on the type of measurement to be saved Therefore we distinguish two types of memory called regular memory and route memory and to leave it we have the choice between To enter the memory we hit the button pressing again b A In order to avoid the errors all operations on the memory are locked if the batteries are low One should then use the external power supply 2 12 1 Regular memory In this
56. number of rotations Tachometer SetuP Averaging Ho of ren Return The keys and vw are used to select the number of rotations 2 7 Temperature versions ST and DT The temperature measurement is possible with versions ST and DT of DIAMOND 401 The measurement is done with the thermocouple of type K which is connected to the instrument through an adequate converter To access the function Thermometer we should press the arrow underneath the corresponding symbol We get then the following display Thermometer 234 6 C Exit There are no parameters to be setup for this function 2 8 Cavitation The cavitation measurements are very useful for the machines where this harmful phenomenon may occur like pumps DIAMOND 401 evaluates the cavitation by measuring DIAMOND 401 20 User s guide the mean value of acceleration in the freguency bandwidth between 5 kHz and 30 kHz To facilitate the interpretation the result is given as a relative value in dB Lata tion AB dE AVG Setup 2 8 1 Settings for cavitation measurement We can adjust two parameters range and averaging time Cowitation SetuP Ranae Huerq ging lz 2 9 FFT analysis To choose this function we press the key underneath the spectral analysis symbol and then the following display appears FFT Analyzer A Exit sSFectrum SetuP Immediately after the words FFT Analyzer is indicated the quantity chosen for analysis for ex
57. oftware The information concerning the measurements that should be performed at each of the measurement points is downloaded together with their names This mode of operation allows the user to easily and efficiently collect the measurement data At any point along the route it is possible to add measurements that were not planned However it is not possible to add the machines or the measurement points If we want to perform additional measurements at points which were not planned then we can always switch back to the regular memory mode and register these measurements under any machine or measurement point number 2 12 2 1 Collecting the measurements in the route memory The route memory has a tree structure the first level is reserved for machines the second for the measurement points on respective machines and the third one concerns the measurements that should be executed at these points The following display reflects the structure of the route memory Memory route vF Hoch ine 1 Paint 1 TOT vu 10 1k och inez Pooch I mes Exit Delete SOVE DIAMOND 401 40 User s guide It is possible to unfold and fold back the tree of the route memory When the tree is folded up then on the screen are listed only the names of machines One of the machine names is always highlighted Using the keys A and 14 we can move around the list until we locate the desired machine By pressing En unfold the corresponding branch and get the list of
58. onal freguency of the bearing cage inner race with respect to the fe 1 2 fo 1 d D coso external race high frequency vibrations from 2kHz to 60kHz Play of slide bearing in 1 2 x fo radial its enclosure 1 3 x fo Instability of the oil layer in the slide de 0 2 a 0 48 x fo radial always lt V fo bearing gear z number of teeth axial bands can appear in the spectrum Mechanical plays 1 x fo radial P a A belt cycle n number of blades axial Electrically excited radial Should disappear once the vibrations axial current is switched off Here is an example of the spectrum obtained in real conditions 1 960 1 820 1 6860 1 540 1 400 1 260 1 120 0 980 0 840 0 700 0 560 0 420 0 280 0 140 0 pope POTY A d ada OEA a WMC LE L 0 500 29 500 56 500 ar S00 116 500 145 500 174 500 203 501 fr quence Hz E m l 1 ll iid F LJ DIAMOND 401 64 User s guide 4 5 Phase measurements Vibration phase measurement is a very interesting tool for the machinery diagnostics In particular it helps to identify the resonance frequencies of the machine structure and for the diagnostic of misalignment of rotors and clutches When the vibrating machine crosses the resonance frequency there is a significant increase in amplitude and change in phase by 180 On the other hand the misalignment of a clutch is identified if the vibrations of bearing bodies on both sides of the clutch are out of phase by 180 Sim
59. or menu BATA From left adjusting time and date selecting the time of power self release connecting and disconnecting charging of batteries OP Tion menu DIAMOND 401 48 User s guide The meaning of the symbols starting from left selecting the accelerometer information concerning the calibration and the self test function 2 13 1 Data transfer to the computer In order to communicate with the computer the user should do the following 1 Connect the DIAMOND to the RS232 port of the PC 2 Select from the Options menu communication with PC 3 From the PC program launch the transmission Once the option of communication with PC is selected the following message is displayed OPTIKY Communication with PL Fead Return The message changes when the transmission is launched OF tion Communication with FL Transmission Return lf there is an error in the transmission then we are warned by the following message DF tion Communication with FL Communication error Return Once the transmission is completed the instrument returns to the Options menu It is possible ESC to interrupt the transmission either by pressing P or by selecting on the screen the word Return However in practice it is recommended to avoid interrupting the transmission without having a serious reason since it may result in the partial loss of information DIAMOND 401 49 User s guide A It is important to m
60. ous elements of the machine and the vibration spectrum We can clearly see where the dominant components are It is recommended to first perform the spectral analysis when the machine is in a good condition When the machine condition deteriorates then the spectral analysis immediately indicates which spectral components have increased their amplitude By comparing the spectra we can draw the conclusions concerning the eventual causes of the problem The degree of difficulty in the interpretation of results depends on the complexity of the machine li is necessary to know well the construction of the machine and its characteristics in order to be able to interpret properly the spectral analysis results Most often the reasons of the problem are the unbalance or the misalignment of rotors or the flaws in bearings The typical failures and their characteristic frequencies are summarized in the table hereafter DIAMOND 401 63 User s guide fo rotational freguency Hz vibrations elements the high level of vibrations inflexion of the rotor axial The percussive pulses depend on the rotational speed and on bearing elements rolling element d rolling element diameter fr 1 2 fo D d 1 d D cosq D pitch diameter of a bearing inner race a fin 1 2 N fo 1 d D cosy radial angle of incidence Flaw of bearing axial element external race N number of rolling elements fext 1 2 N fo 1 d D cos m o 9 fo rotati
61. ously it is possible to edtit three digits and as previously by pressing we confirm and close the edition To quit the edition without making any change one should press Once the edition is completed we select Next and we move on to the measurement with test mass Obviously before starting the measurement we should place the test weight in the indicated location Balancer 1P Test run 4 23 nme ele 349 29H46 FF Bock Hest Setup To start and to stop the measurement we use as always the button Pike and we continue once the measurement is completed On the next screen appears the first balancing result indicating the correction mass m0 DIAMOND 401 31 User s guide Balan er 1F Result correction mass m 130 343 Bock Hest Setup We remove from the rotor the test mass and we install at the indicated on the screen location the correction mass m0 A The location at which was installed the test mass is considered as reference 0 We measure the angle with respect to this reference in the direction opposite to the rotations of the machine This rule holds for all locations of the correction masses When it is not possible to place the weights at the indicated locations then the solution consists in breaking down the results into components If for example we have 6 mounting points rellocated every 60 that means that in the settings we have selected No of fixed location 6 To break
62. rd Phase Below on the left side is shown the result for the first harmonic on the right for the second harmonic and in the middle the rotational speed 2 5 1 Settings for phase measurement After having selected Setup in the menu above we get the following display Prose Setur Type Tracking filter Fange Averaging Ho of ren Return The table below shows the parameters that are measured for given quantities Averaging Quantity Range Filter number of bandwidth rotations 5 50 500 m s AUTO 0 05 Hz Velocity 5 50 500 mm s AUTO 0 5 Hz D Displacement 50 500 5000 um Auto Explanations Averaging the rotational speed is averaged from the selected number of rotations The selective filter is tuned to this speed Filter bandwidth the bandwidth of the selective filter that is used to filter out from the vibration signal the first and second harmonic components To start and stop the measurement we use the key START STOP DIAMOND 401 19 User s guide 2 6 Rotating speed measurements versions D and DT By selecting the appropriate symbol we access the function Tachometer The measurement result is displayed simultaneously in two units Hz and rom Tachometer 29 428 Hz 17845 rpm Exit Setup 2 6 1 Settings for speed measurements In the corresponding menu we are able to adjust only one parameter Averaging No of rev The rotational speed will be averaged from the selected
63. sing of the memory are done with the help of memory Setup When we are in the memory menu and we press the key then the screen will look like this Hemort regular Machine Point no 0014 01 fi Measurement 1 Measurement 2 Measurement 3 Measurement H Exit By choosing Setup we get into the memory management menu Hemort SetuF TYPe of memory Hemor free Erase THFE Return By choosing Type we can switch between the regular and route memories if the information concerning the route wasnt introduced into the instrument then the choice of route memory is not available If we have chosen the regular memory and we would like to erase it then we should hit the arrow underneath the word Erase DIAMOND 401 39 User s guide Hemort Setuf Erase regular memory 7 YES H Return To confirm we choose YES if not NO or Return If we have chosen YES then we must confirm our choice Memory Setur Contirm erasing YES H Return This is the last moment when we can still avoid the erasing of the memory by either selecting NO or Return li however we confirm and choose YES then the regular memory will be erased 2 12 2 Route memory This type of memory is designed for collecting the data accordingly to the predefined measurement route In this mode all machine and measurement point names are downloaded from the computer This measurement route is first conceived on the computer using the MBJLab s
64. splayed on the first line next to the word Route 2 12 2 2 Adding extra measurements to the route memory It is possible to record an additional measurement at each measurement point of the route memory To do that and once this extra measurement is completed we switch to the memory mode place the reverse video on the corresponding point and press the arrow underneath the word Save The measurement will be saved alongside this point 2 12 2 3 Displaying the measurements from the memory To visualize a measurement one should select this measurement by highlighting it in the list and press pa The selected measurement will be displayed on the screen and the letter M which appears on the top of the screen indicates that this measurement originates from the memory By pressing we return to the memory tree Obviously we can only view DIAMOND 401 41 User s guide the measurements which are completed that is those having the sign v next to their names 2 12 2 4 Canceling the measurements To delete a measurement we must select it by placing the reverse video on its name and press A which is just below the word Delete 2 12 2 5 Repeating the measurement on the route lf for any reason we would like to repeat a measurement that is already recorded in the route memory then we should place the reverse video on its name and press START STOP The following question is displayed on the screen Hemort route FePeot measurem
65. the one to be used for standard use I l measurements we should press lt By pressing the arrow underneath the word Details we get the complete information concerning the selected transducer Sensor 1 be HUT Serial number SH 18286 Sensitivity 4 rl Return To quit this option we select Return or press me 2 13 8 Calibration DIAMOND 401 54 User s guide This option will tell us when took place the last calibration and when should be performed the next one It is recommended to calibrate the instrument once per year but it is obligatory to do it at least every second year The customer may return the instrument to the factory or give it to the laboratory that is equipped for the job The PC program guiding through the calibration procedure is provided with the instrument Selecting CAL will bring the following display OF tian Lost calibration O2 02 2003 Hest calibration 2 02 2004 Return 2 13 9 Instrument self test DIAMOND 401 is capable of testing its measurement channels in order to verify whether they are working correctly By selecting TEST we get OPTIKY Self test 100 a Return If the result of self test is positive then we are sent back to the Options menu On the other hand if there is a problem then we get the following message OF tion Self Test Return In this case we should repeat the test by selecting Return and once more TEST lf the result is again ne
66. tion level or the residual unbalance are reduced to the acceptable level 4 7 2 Two plane balancing The two plane balancing should be applied in the case of wide rotors of cylindrical shape Any time it is possible one should choose for the corrections the two planes at the both ends of the rotor The vibration measurements should be made in the planes corresponding to the location of bearings It is illustrated in the following drawing N aa S1 S2 locations where the measurements are done P1 P2 planes where will be applied the corrective masses The procedure for two plane balancing START Installation of two accelerometers close to bearings at the ends of the rotor placing the marker on the rotor and installation of the tachometer Preliminary measurement of vibrations and phase on both planes Placing the test weight on the first plane Vieasuring vibrations and phase on both planes with test weight mp on the first plane Dismantling the test weight from the first plane and its installation on the second plane Measuring vibrations and phase on both planes with test weight mp on the second plane Interpreting the results corrections m0 P1 et m0 P2 separately for the first and the second plane dismantling the test weight and mounting the correction masses on their respective planes Measurement to verify the effect of the correction masses m0 P1 et m
67. tionalities of the instrument By pressing one of these keys we select the corresponding function Pressing the DIAMOND 401 12 User s guide key changes cyclically the available functionalities by sets of three Below are shown the displays with icons corresponding to various functionalities available in the main menu of DIAMOND 401DT DIAMOND 401 exists in four versions which differ by the number of available functionalities Moin menu dze DIAMOND 401 From left to right vibrometer bearings verification spectral analysis Moin menu W253 DIAMOND 401 From left to right RPM measurement temperature measurement balancing Moin menu Es DIAMOND 401 Sj gej From left to right phase measurement cavitation detection Obviously the number of functions that are displayed in the main menu depends on the version of the instrument All these function are described in the following paragraphs 2 3 Vibration level meter The following screen appears when the function vibrometer is selected DIAMOND 401 13 User s guide m 10Hz 10kHz P K i P P Exit Evaluation SetuP The character immediately after the word Meter in the first line indicates the quantity being measured in this case A for acceleration Completely to the right of the first line there is a space for a symbol of discharged batteries next to it is a symbol indicating that the measurement is being executed it
68. urement overload DIAMOND 401 3 User s guide 2 12 Memory management 2 12 1 Regular memory 2 12 1 1 Measurements recording in the regular memory 2 12 1 2 Displaying and canceling the measurements 2 12 1 3 Repeating a recorded measurement 2 12 1 4 Erasing the regular memory 2 12 2 Route memory 2 12 2 1 Collecting the measurements in the route memory 2 12 2 2 Adding extra measurements to the route memory 2 12 2 3 Displaying the measurements from the memory 2 12 2 4 Canceling the measurements 2 12 2 5 Repeating the measurement on the route 2 12 2 6 Erasing the route memory 2 12 3 Designating the measurement types in the memory 2 12 4 Formatting the memory 2 12 5 Memory messages 2 13 Options 2 13 1 Data transfer to the computer 2 13 2 Contrast 2 13 3 Brightness 2 13 4 Time and date 2 13 5 Power self release 2 13 6 Battery charging 2 13 7 Accelerometers 2 13 8 Calibration 2 13 9 Instrument self test 3 Accessories 3 1 Sensors 3 1 1 Accelerometers 3 1 2 Rotational soeed measurement sensor 3 1 3 Temperature sensor 3 2 Cables 3 3 External power supply 4 Theory 4 1 Vibration measurements and machine condition evaluation 4 1 1 Machinery vibrations DIAMOND 401 4 User s guide 4 1 2 Inspection and maintenance 4 1 3 Vibration measurements 4 2 Standards 4 2 1 ISO 10816 1 standard 4 2 2 ISO 10816 2 standard 4 2 3 ISO 10816 3 standard 4 2 4 ISO 10816 4 standard 4 3 Bearings 4 3 1 Measurement of shock pulses 4 3 2 Envelope measure
69. ursor These two modes of A cursor are used to eliminate the error introduced by the leakage the frequencies generated by a machine usually do not correspond to the locations where are calculated by FFT the spectral lines and therefore the energy contained in a frequency generated by a machine is redistributed on several spectral lines The function A cursor helps to gather up this energy by adding the spectral lines delimited by the dotted lines and therefore it produces the accurate value Below is shown an example with A cursor activated The results of the spectral analysis are continuously refreshed on the screen To stop the analysis we should press the key START STOP The last result remains on the display The key is used to erase the display FFT Hnaldzer A Exit SPectrun Setup To review the last result we should with the arrow key underneath the screen select Spectrum To quit the FFT analysis we can select Exit or press 2 10 Balancing versions D and DT The unbalance of rotating parts is the most commonly encountered reason for the deterioration of a machine s condition It is characterized by a high level of radial vibrations having the frequency which corresponds to the rotating frequency DIAMOND 401 has options for balancing the machines in their bearings and it can be used to perform the measurements and calculations necessary to get the job done To be able to perform the balancing we need to
70. xis range The three symbols lt lt gt lt and gt gt represent starting from the left shifting the cursor by 1 10 of the display to the left centering the cursor at the middle of the display and shifting the cursor by 1 10 of the display to the right By pressing the key MENU we change these functions as shown below Alternative functions f E3620 Hz A 3 2 Z Now starting from the left we have vertical expansion of the display vertical contraction of the display and zoom function and 8 or to the right and the keys axis The function A cursor helps to add the values of the spectral lines While setting up the FFT analysis one can choose several modes for A cursor off total constant ana DIAMOND 401 24 User s guide relative When this function is off then the spectral value indicated by A cursor is equal to the value indicated by cursor When it is set to total then its value is equal to the sum of all spectral lines When A cursor is set to constant or relative then we should also specify the number of the spectral lines When the choice is constant then this number indicates the absolute width of the window while in the case of relative the width of the window is expressed as the percentage of the central frequency of the cursor The portion of the spectrum that was thus selected is indicated on the screen by two vertical dotted line disposed symmetrically on both sides of the c

DIAMOND 401 user manual - roga

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