user manual - Advanced Measurement Solutions
Contents
1. D I start 3 advanced Measurem D 23 53 Before zoom 32 H Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility l V Oo J ja xf File VBT Settings FFT Settings Display Run Help Y axis TORQUE Hamming Total energy fi 1065983698 7 Parseval formula DC value fi 904321 0403 Floorlevel 2542 2003 Even simmetry max error Re 1 4343e 006 Odd simmetry max error Im 6 8995e 006 Zoom 8 Marker 1 Marker 2 Y axis Marker 1 On Off Y axis Marker 2 On Off Ampl Ampl 2mpl dB Ampl dB m Marker 1 Marker 2 variation Ampl var Ampl var dB X axis Sampling frequency Hz 570 18 Number of samples 2048 m Marker 1 r Marker 2 x axis Marker 1 On Off x axis Marker 2 On Off Line Line Ll Freg Hz Freg set Hz Ample Ample Ampl dB Amps 2 gt Marker 1 Marker 2 variation Lines es Ampl var Freq var Hz Ampl var dB Si start advanced Measurem D 23 54 After zoom After zooming it is possible to scroll the window along the X axis clicking on the left and right arrows of the horizontal scroll bar or inside the bar 6 Restore X axis F9 Selecting the menu Display Restore X axis or pressing F9 function key it is possible to zoom out and view the complete graph zoom 0 Note Switching between different display modes or loading a2. System Parameters xX Notice Parameters will display only after BT file processing Shatt parameters System parameters Date 25 05 2006 Giovedi Time 10 59 16 Counter period t 03516875 L mmj 370 0 Rextirmm 40 0 Rintimm 0 0 RPM max 451 U Discs parameters N_SLOT mn A SLOT degrees 20 Perc_Slot 031 8 GIN sgmm 82404 0 VBT filter settings Selecting the menu VBI Settings Filter settings or pressing F6 function key calculation algorithm parameters can be adjusted BT processor filtering setting E Ei Warning The setting below will overide default and VET file values Press Cancel to keep previous settings Allowed overshat 7 0 1 Moving average filtering length H 0 RPM threshold 180 Zero crossing filter length la Cancel le Hote Allowed overshot default value 0 1 10 Moving average filtering length range 5 200 default 10 APM threshold default value 40 of masimurn APM ero crossing filter length range 4 30 default 4 18 If sampled data are free from noise and the sampling is carried out at a constant shaft speed the default values of these parameters are normally correct and need not to be modified In most cases only Zero crossing filter length and Moving average filter length could need some adjustment After the parameters are modified the OK pushbutton must be pressed to make the changes permanent In case the u
3. of the masimum APM of the shaft see APthimas parameter in VET file header d lt is possible to set a customized value of the ero crossing filter length that is the minimum number of samples with inverted HM sigh after which the the inversion of the sense of rotation is acknoledged The default value ts 4 samples Possible values ranges from 4 to 30 samples 5 lt is possible to select a different name for the FOM output file using File Save as FOM File F4 This option is usefull when after processing the input file with the default values you want to reprocess the file using a customized filtering parameters shoring the output data to a different file 6 ln case the original ET file iz lost and only the output TOM file 12 available this lather file can be opened as a source file and all the processing can be carried out This option is available selecting File Open TOM file The name of TOM input TOM and FOM output files must be speched TOM output and TOM input filenames must be different 4 In case the original ET file ts lost and only the output FOM file 12 available this lather file can be opened as a source file and all the processing can be carried out This option it available selecting File Open EDM file F3 The name of EDM input TOM and FOM output files must be specified FOM output and FOM input flenames must be different 18 With Display Display control F7 the graphie to be displayed may be selected Horizontal and ver
4. Y axis Marker 1 On Off Y axis Marker 2 On Off Ampl Ampl Ampl dB Ampl dB Marker 1 Marker 2 variation Ampl var Ampl var dB X axis Sampling frequency Hz 570 18 Number of samples 2048 Marker 1 Marker 2 x axis Marker 1 On Off x axis Marker 2 On Off Lines lines Freq Hz Freg Hz Ampl Ampl KZ ant dB Ample IT dB Marker 1 Marker 2 variation wy Lines Ampl var dl Vay lying Fregwar Hz Ampl va E at gt E start advanced Measurem D 23 47 26 Display armonics peaks euristic When checked this checkbox enables the euristic calculation of all FFI peaks distinguishable from the floor noise The DC component and the floor are first cancelled After this a spectral line is considered a peak if it stands up from the floor level In this case the three spectral lines at the right and at the left the tails of the peak are cancelled Moreover also the additional ripple at the right and at the left of the peak below 1 5 of the difference of amplitude between the fundamental and the floor level is cancelled This option is useful for a first glance characterization of the FFT sH Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility File VBT Settings FFT Settings Display Run Help Y axis TORQUE Hamming Total energy 11065983698 7 Parseval formula DE value fi 904321 0403
5. incidentally consequentially fraudulently can cause damage to things menace human life and or cause physical injuries to persons even if the system is only part of a more complex one are expressingly forbidden In case the user wished to use the system in one of the above mentioned applications he she must obtain the written permission from the manufacturer beforehand The manufacturer shall not be liable for any direct indirect special incidental consequential fraudulent damage of material and non material nature caused by correct or improper usage of the system Moreover the manufacturer shall not be liable for any economical and or financial damage loss of profits or business caused by the usage of the system The manufacturer shall not be liable for any expenses claims or suits arising out of or relating to any of the foregoing 1 Installation and setup LTM2114 FDM installation is very simple It is sufficient to copy LTM2214 FDM EXE file in the working directory and start the program Then the serial number will be requested Note Being LTM2214 TDM time domain software utility a freeware it does not require registration Therefore in case this latter utility is used the following steps are not applicable Advanced Measurement Solutions Serial check xj SERIAL NUMBER Demo Version Registered Version Input the serial number printed on the CD case and select Registered Version The program
6. line of the FFT calculation file fdm file wl IN ui Wir ln d d HV i ul IN dl f d i K IN d Wu d i Ill ui AAN WH i iv WW d NANA ll A lla wd ug Li A Wild LA ll 101 11111111111 111111111111111111111111111111111 11111111111 Il 11111111111 d Jud Hild Old GUDD HANNAHI Ml LLL LLL LLL Lt Ll tute 20 Display armonics analytic When checked this checkbox enables the display in a different colour of the spectral lines of the fundamental and of all its armonics The fundamental is calculated analytically as the first peak following the DC component Note As it is not always possible for the algorithm to find the exact centre frequency of the fundamental in some cases it may happen that the armonics spectral lines are not exactly centered at the armonic peak In any case this option is very useful for a first evaluation of possible armonics of the fundamental e Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility File VBT Settings FFT Settings Display Run Help Y axis TORQUE Hamming Total energy fi 1065983698 7 Parseval formula DC value 1304321 0403 Floor level 2542 2003 Even simmetry max error Re 1 4343e 006 Odd simmetry max error Im B 8995e 006 Zoom fi 00 Set Marker 1 Marker 2
7. Advanced Measurement Solutions Laser Torque Meters LTM2214 FDM Time and Frequency domain analysis tool for LIM2214 Laser Torque Meter USER MANUAL Rev 2 0 English version web www AdvancedMeasurementSolutions com email info AdvancedMeasurementSolutions com O Introduction s 0 1 Manufacturer responsibility Installation and setup Program operation Calculated parameters Parameters manipulation Display control F7 Restore X axis F9 Y axis panels Index sheet sheet sheet sheet sheet sheet sheet sheet sheet sheet sheet 14 18 24 33 33 35 36 Preface The LTM2214 FDM time and frequency domain analysis software tool is based on LTM2214 TDM time domain analysis software tool and includes all the features of the latter For this reason this manual can be used also for LTM2214 TDM software tool except where validity limited to LTM2214 FDM is expressingly indicated Note In case only time domain functionality is required LTM2214 TDM time domain analysis software tool can be used LTM2214 TDM is a freeware tool downloadable from our web site Trademarks Microsoft Paint and Excel are a trademarks of Microsoft Corporation The name Advanced Measurement Solutions and the relevant logo are trademarks of Advanced Measurement Solutions Patents The laser torque metering technique used by LTM2214 is patented Notice Product characteri
8. Floor level 2542 2003 Even simmetry max error Re fi 43438 006 Odd simmetry max error Im 6 89958 006 Zoom fi 00 Set Marker 1 Y axis Marker 1 On Off Ampl Ampl dB Marker 1 Marker 2 variation Ampl var Ampl var dB Marker 2 Y axis Marker 2 On Off Ampl Ampl de X axis Sampling frequency Hz 570 18 Number of samples 2048 E Marker 1 Marker 2 x axis Marker 1 On Off x axis Marker 2 On Off Line Es Line Sen Freq z Hz Freg HH Hz Ampl ses Ampl see ww ange Fe Marker 1 Marker 2 variation Lines Ampl var 41 E Freq var Hz Ampl var dB E start E Advanced Measurem 23 48 27 Clean spectrum DC component floor When checked this checkbox removes from the display the DC component and the floor level of the FFT The removed components will be zeroed Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility 28 5 2 Time domain display selection Selecting one of the radio buttons of the group Select auxiliary graph to display it is possible to select one of the six time domain displays available Advance d Measuremen t Solutions LTM2214 Laser Torque Meter Frequency Domain Utility RPM filtered Torque Power Advance d Measuremen t Solutions LTM2214 Laser Torque Meter Frequency Domain Utility RPM unfiltered Torque Power e E d
9. alculated frequency domain data which can be displayed are Torque pulse raw data FFT Torque pulses FFT calculated starting from torque pulses stored in the input file Filtered RPM FFT Filtered RPM FFT with a moving average filter whose length can be set by the user Unfiltered RPM FFT Instantaneous RPM FFT without moving average filtering Torque FFT Torque FFT calculated starting from filtered RPM and torque pulses stored in the input file Power FFT Power FFT calculated starting from Torque and filtered RPM The headers of tdm and fdm files contain additional information used to initialize correctly calculation parameters mechanical system sampling and filtering parameters etc TDM file data structure A typical tdm file header can look like the following 1 Vibrotorsional Time Domain Analysis 2 Rev 1 0 3 Date 27 04 2006 Thursday 14 Time 10 59 16 Counter period 2 893501uS G 82404 0N sqmm Rext 40 0mm Rint 0 0mm L 910 0mm 10 N_SLOT 80 0 11 A_SLOT 2 0degrees 12 Perc_Slot 0 497 13 RPMmax 450 0 14 PCoeff 1 0 15 PDist 1 0 16 Allowed overshot 0 1 17 Moving average filtering length 10 18 RPM threshold 180 0 19 Zero crossing filter length 4 DOA Parmeters from 5 to 15 are explained in LTM2214 laser torque meter operating manual Parameters from 16 to 19 used to process the input file and to generate tdm and fdm files are explained below Allowed overshot
10. between marker 1 and 2 with absolute value and dB display Total energy display calculated with Parseval formula Absolute DC value display Absolute Floor level display Even simmetry maximum error Real part display Odd simmetry maximum error Immaginary part display gt oo JO Om Note Even and odd simmetry error values are used as FFT reliabilty indicators They are calculated as the difference between original time domain input data and the output of inverse FFT calculated using direct FFT output data as input The smaller these errors the more precise the direct FFT output data Normal values are normally lower that 10 5 For a good FFT these values are usually in the range of 10 6 Values higher than 10 4 are an indication that FFT precision is limited 8 Process File F10 selecting the menu Run Process File or pressing F10 function key the input file processing is forced Note With this revision of the utility this function needs not to be used as automatic recalculation is always activated after every parameter modification This function has been kept for compatibility with older revisions of the utility 35 9 Help Selecting the menu Help Online Help or pressing F1 function key the help dialog window is displayed This dialog lists briefly the main functions of the utility ar A LTM2214 Laser Torque Meter Frequency Domain Utility Help e em Advanced Measurement So
11. d to process the input file and to generate tdm and ones and were explained before Parameters from 21 to 24 are explained below Sampling Freq Fc Hz xxxx 16 Is the calculated sampling frequency in Hz used in FFT calculation Samples Number N xxxx Is the number of samples 2 N used in FFT calculation The actual number of samples in the input file could be bigger Unusable samples are not considered Filtering window Xxxxxx Is the type of the filtering window used flat top hamming blackman Input data xxxxxx Is the type of data of which the FFT is calculated Torque raw pulses RPM filtered RPM unfiltered Torque Power The fdm file output data structure is quite simple The following data are stored in fdm files 1 Progr Progressive number of the spectral line 2 Freq Hz Frequency of the spectral line 3 sqrt Re 2 Im2 2 Amplitude of the spectral line 4 Notes Indication of fundamental and or of armonic frequencies At the end of FFT data the following string is found SPEND OPF FETS Then the original vbt file follows 17 4 Parameters manipulation LTM2214 FDM utility permits several parameters manipulation in order to improve the accuracy of time and frequency domain analysis 4 1 VBT Settings Parameters display Selecting the menu VBT Settings Parameters or pressing F5 function key mechanical system parameters are displayed Advanced Measurement Solutions
12. dow The Hamming window has a good roll off and a high stop band attenuation 60dB For this reason it preserves the actual amplitude of the armonics but widens their tails In some cases two armonics very close in frequency can merge and become almost undistinguishable Apart from this Hamming window is the most used filtering window Blackman window The Blackman window has a worse roll off compared to Hamming window but a higher stop band attenuation 80dB It preserves the amplitude of the armonics better than the Hamming window but widens their tails even more So Blackman window is not used very often only in cases where Hamming window fails to preserve armonics amplitude Considerations on filtering selection Below are represented the FFI graphs of the reference function see demo mode calculated using the three different filters The difference in calculated amplitudes can be well appreciated looking at the markers values of the fundamental and of the first armonic Hamming and Blackman spectral lines amplitudes are comparable while Flat Top amplitudes are quite different even if armonics width is narrower and armonics tails shape is more realistic So the typical approach is to first use Hamming filtering to get an overall overview of the FFT then using the Flat Top filtering the presence of hidden merged armonics can be detected Afterwards in order to assess armonics amplitudes Blackman filtering can be used to conf
13. ettings FFT filtering or pressing F12 function key it is possible to select the filtering function used by FFT algorithm Three functions can be selected Flat too Hamming Blackman FFT filtering window selection X Select FFT filtering endo DR Windowed Flat top zinc rectangular no filtering no stop band attenuation 10131 Ce Windowed Hamming sinc good roll off low stop band attenuation 60d8 Cancel Windowed Blackman sine medium roll off good stop band attenuation 80db 19 Flat top window The flat top filter is a rectangular window so actually it performs no filtering at all stop band attenuation 008 The main advantage of flat top filtering is that armonics can be distinguished even when their frequencies are very close So virtually no armonics is lost The main disadvantage of flat top filtering is that armonics amplitude can vary significantly depending on how much the center frequency of the armonic is close to a spectral line If the armonic frequency does not coincide with a spectral line only the tails of the armonic will contribute to the computation of armonic s amplitude and so the armonic amplitude will be smaller that what it actually is For these reasons flat top is suggested only at a first stage of the investigation to be sure not to miss any armonic Then it is more advisable to move to Hamming or Blackman filters which preserve armonics amplitude more efficiently Hamming win
14. i 29 14 Laser Torque Meter Frequency Domain Utility Advanced Measurement Solutions a Nee SE SH AA EIA ADAC A AAA AA AAA ANA AAA AAA e pe E A gneve mena ne A 222 Ss SE SE SE SC 2 dvanced Measure 0 on fw gt lase or eter Frequency Do A Y Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility lt 2 br GE 1 SSC 12 ZE 12151537792 1 2 2225 2 z ae SE S ES 12575 Sees 22 SS 2527 Be SE H Ady dMi RPM unfiltered Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility Torque Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility 31 X axis zoom F8 Selecting the menu Display X axis zoom or pressing F8 function key it is possible to zoom the graph between marker 1 and maker 2 The markers must be set before zooming To set marker 1 select X axis Marker 1 On Off in the X axis panel Then position the mouse on the screen at the desired position and click the left button Marker 1 will display in red colour To set marker 2 select X axis Marker 2 On Off in the X axis panel Then position the mouse on the screen at the desired position and click the left button Marker 2 will display in cyan colour Marker 1 must be set at a lower value than marker 2 Note As markers default value is always zero it is not normall
15. ilt Nm Filtered torque value in Nm POTfilt kKW Filtered power in kW Cislot Number of counts between two consecutive slits Cslot Number of counts in the current slit slit width TRQOcnt Number of calculated counts at zero torque at RPMinst speed 10 dTRQinst Count variation from zero torque to TRQinst 11 RPMinst Instantaneous RPM value 12 TRQinst Nm Instantaneous torque value in Nm 13 POTinst kW Instantaneous power value in kW CON DO At the end of TDM data the following string is found gt gt END OF TDM Analysis lt lt Then the original vbt file follows FDM file data structure A typical fdm file header can look like the following 1 Vibrotorsional Frequency Domain Analysis Rev 1 0 Date 27 04 2006 Thursday Time 10 59 16 Counter period 2 893501uS G 82404 0N sqmm Rext 40 0mm Rint 0 0mm L 910 0mm 10 N_SLOT 80 0 11 A_SLOT 2 0degrees 12 Perc_Slot 0 497 13 RPMmax 450 0 14 PCoeff 1 0 15 PDist 1 0 16 Allowed overshot 0 1 17 Moving average filtering length 10 18 RPM threshold 180 0 19 Zero crossing filter length 4 20 FFT Output limited to Nyquist frequency 21 Sampling Freq Fc Hz 326 1432552 22 Samples Number N 4096 23 Filtering window Hamming 24 Input data Torque raw pulses Cslot 9 OP Parameters from 5 to 15 are explained in LTM2214 laser torque meter operating manual Parameters from 16 to 19 are the one use
16. in Utility File VET Settings FFT Settings Display Run Help Document recent Desktop EN Document E Risorze del computer Ri 11068 EDM ER Risorse di rete Tipo file FOM Files 703 T Apri in sola lettura b After selecting the input file other two dialog boxes open The program generates two output files a time domain file tdm and a frequency domain one fdm The user must type the names of the two output files Note In case at item a a tdm or a fdm input file has ben selected the user MUST select a different name for the output tdm and fdm files which will be generated Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility File WBT Settings FFT Settings Display Run Help Create TDM file x Salva in 15 mockUp1_100pe e Ese Document recent Desktop Documenti K SE Aizorze del computer Nome file Jtest2 e as Salva come TDM Files ralla E outfile1 TDM seq Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility File BT Settings FFT Settings Display Run Help Create FOM file outfile1 FDIM OCUMER ti recent Desktop D acumen ti mr ar Risorse del computer KW Home file fest Eiers di 171 Salva come FOM Files Annulla Processing will then start and if the registered version of the program is
17. irm the values calculated with Hamming filtering For a quick analysis only hamming filtering can be used 20 Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility A eee C ea en a l l m l l l a e ee a ene _ E LEU Be Flat Top filtering Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility A eee a er eee Hamming filtering 2 Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility a ee ee nn Blackman filtering Y asis Marker 2 09001 22 FFT input selection selecting the menu FFT Settings FFT input selection it is possible to select the input data set of the FFT algorithm FFT source selection Ki Select FFT input data Torque pulses raw data C Filtered RPM filtered ance C APM unfiltered fe Torque filtered Default Power filtered Five input data sets can be selected Torque pulse raw data Filtered RPM Unfiltered RPM Torque filtered default selection Power filtered ee Normally only torque and power FFT are used while the other input are used to verify the reliability of calculated FFT In fact if torque and power FFT are reliable filtered and unfiltered RPM and often pulse torque FFTs should be
18. lutions IS LI M2214 Laser Torque Meter Frequency Domain 4nalisys Utility ver 2 00 WHA Sdvancedm easurementS alutions cam 1 To use the program first select the YET input file to open and the TOM output file to create with File Open BT File Fe 2 Then the processing starts automatically or can be started with Aun Process File IEIUI 3 After processing the BT file with the standard parameters itis possible to display VET file header data using Setting Parameters F5 4 It is possible to change the filtering settings using Settings Filtering settings FE To prevent customized values from becoming effective exit the dialog pressing Cancel a lt is possible to set a customized overshot value that i the percentage value of overshot beyond which a sample is considered spurious and thus must be discarded its position 13 10180 with the linear average of the preceeding and following samples default value i 0 1 that is 10 of preceeding value b It i possible to set a customized length of the moving average of the samples the default value used is 10 Possible values range from 5 to 200 Using lower values some residual spurious samples may appear using a higher value the curve is smo othed and some peaks may be filtered c lk is possible to set a customized value of the APM threshold that is the minimum APM value below which the program checks if the sense of rotation of the shaft has changed The default value is 40
19. new file does not modify the previous zoom coefficient So in this case it is necessary to press 19 to restore the X axis zoom percentage to 0 to have an overall view of the graph 7 Y axis panels Y axis panels contain many useful informations on the currently plotted graph Two different panels are shown depending on the selected mode TDM or FDM TDM mode panel TDM mode panel has one or three subpanels depending on the number of displayed graphs The following information are displayed 33 Scale factor Each subpanel has an adjustable zoom factor with initial autoscale function To modify the scale factor the new scale must be typed in and then the button Set must be pressed oom f 00 Set Y axis Marker On Off Marker val 11811111177 420 3 11111111111 455 5 TORQUE Yaris o0m f 00 Ei Y axis Marker On Off Marker val Maximum 2053 2 Minimam 4851 1 POWER Yaris o0m f 00 Gel ais Marker 01 0 ais Marker 01 0 Marker On Off Marker val 11711111177 113 3 11117111171 125 1 A axis Markers Enable di Ge Marker 1 Markers Time Speed Trq Hm Fow F TDM mode Y axis panel Y axis Marker la x oul Y axis TORQUE Hamming Total energy 10859535957 Parzeval formula DC value 1904321 0403 Floor level 2542 2003 Even simmety max error Diet f 434 ie Odd simmetry max e
20. rror Im 9955 006 o0m H 00 rel Marker 1 Y axis Marker 1 On Off Arp Marker 2 Y axis Marker 2 Und Ampl Ampl mpl X axis Sampling frequency Hz E 9 Number of samplez 2048 Marker 1 Marker 2 5 ans Marker 1 On Off axis Marker 2 On Off Line Freg Armpl Marker 1 Marker 2 variation 17825 Ampl var le ent a 7 7 Fregvar 112 Amplvar 0B E 23 44 FDM mode Y axis panel To activate one of the Yaxis markers the Y axis Marker On Off buttons must be selected Then the mouse arrow must be positioned on the screen at marker desired position and mouse left button clicked After this the Marker val field will display the graph value at the marker position 34 Maximum and Minimum fields Maximum and Minimum fields display the overall maximum and the minimum of each plotted function also of the portion outside the zoomed window FDM mode panel The following functions of FDM mode panel work in the same way as in TDM mode one 1 Scale value 2 Y axis Marker 1 On Off 3 Y axis Marker 2 On Off 4 Marker 1 and 2 absolute amplitude fields In addition FDM Y axis panel has the following functions 1 Name of plotted parameter 2 Type of filtering Flat top Hamming Blackman 3 Marker 1 and marker 2 amplitude in decibel dB calculated with respect to the DC value Markers variations difference
21. ser wanted to keep the old values it is sufficient to exit the dialog box pressing the Cancel button These are the parameters that can be adjusted see also chapter 3 Allowed overshot Is the maximum overshot allowed in Torque variations beyond the allowed oveshot threshold are considered as spike noise and filtered out An excessively low value of this parameter will filter also valid samples The default value is 0 1 10 Moving average filtering length Is the length of the moving average filter The longer the filter length the larger the number of the data that will be smoothed and of the details which will be lost The default value is 10 The parameter can range from 5 to 200 RPM threshold Is the minimum RPM speed below which the inversion of the sense of rotation is considered as valid An inversion of the sense of rotation which happens at a higher speed is considered as invalid also because it would be mechanically impossible and thus filtered out The threshold is calculated as 0 4 of the maximum RPM set in LTM2214 laser torquemeter hardware Zero crossing filter length ls the minimum number of samples with inverted sense of rotation after which inversion is considered as valid An inversion of the sense of rotation which lasts for less that this length is considered as invalid and filtered out The default value is 4 The parameter ranges from 4 to 30 4 2 FFT Settings FFT filtering Selecting the menu FFT S
22. sional sampling data file vbt selecting File _ Open VBT file or pressing F2 function key Note This type of file is generated by LIM2214 laser torque meter hardware in vibrotorsional sampling mode Advanced Measurement Solutions LIM2214 Laser Torque Meter Frequency Domain Utility File VET Settings FFT Settings Display Bun Help ES Cerca in mockUp1_100pe zl cr Ee ie D 02 umenti Tec enti Desktop 7 li bbb Ia ccc VBT 19 1356_004_2pc WBT 411356 _004_20pe BT 1 1356_004_4Opc YBT 11 1356_004_S0pc VBT a Documenti Wr Risorse del Computer 14010055897 1226 008 V8T Risorse direte Tipo file ver Files E Annulla Apri in sola lettura E 2 loading an intermediate time domain data file tdm selecting File Open TDM file Advanced Measurement Solutions LIM2214 Laser Torque Meter Frequency Domain Utility Fle VET Settings FFT Settings Display Run Help I Open TOM file Cerca in 15 mockUpt 10006 e E e Er Document recent Desktop Document e Risorze del computer outfiled TOM Bag Nome file ftest2 TDM sl SE Tipo file Tom Files si SEN 7 Apri in sola lettura 3 loading a frequency domain data file fdm selecting File Open FDM file or pressing F3 function key 4 Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Doma
23. smooth and monotonous Peaks or discontinuities in these latter FFTs are symptoms of an insufficiently constant sampling frequency due to excessive RPM variations In these cases it is advisable to perform a new and more accurate vibrotorsional sampling Note In demo mode this dialog box has no effect as a reference function not related to the input file is always fed to the FFT algorithm 23 9 Display control F7 Graph display selection Selecting the menu Display Display control or pressing F7 function key it is possible to select the graph to plot on the VDU Both frequency and time domain graphs can be selected The graph to be displayed is selected clicking one of the radio buttons Display Settings Select FFT graph f Currently active FFT source default wiew Display spectral lines Display armonics analytic Display armonic peaks euristic Clean spectrum DC component floor Select auxiliary graphs to display RPM filtered Torque Power APM unfiltered Torque Power E DEM filtered RPM unfiltered Torque Power 5 1 FFT display options In case currently active FFT source is selected several additional options are available activating the check boxes A combination of the check boxes can be selected 24 Display spectral lines When checked this checkbox toggles between envelope and spectral line display Each spectral line corresponds to an output
24. stics are subject to modifications without notice Drawings photographs and video captures may differ from the actual product O Introduction LTM2214 FDM time and frequency domain analysis utility is a powerful software tool for LTM2214 laser torque meter system measurements analysis and interpretation LTM2214 laser torque meter used together with LTM2214 FDM software tool is a complete measurement and analysis system which can carry out an accurate time and frequency domain analysis of the working parameters of the prime mover shaft assembly For additional information document updates software downloads and news please visit our website www AdvancedMeasurementSolutions com or contact us at the email address info AdvancedMeasurementSolutions com 0 1 Manufacturer responsibility The user must read carefully the following legal note The usage of the instrument implies the complete acceptance of all the terms of the following notice Should the user not agree even partially with it he she must not proceed to install and use the software tool See also LTM2214 laser torque meter legal note IMPORTANT NOTICE LIM2214 torque meter system together with LTM2214 FDM time and frequency analysis software tool or LTM2214 TDM in the following text referred to as system is a measurement system and as such must be used only to obtain measurements store and analyze them All applications of the system which directly indirectly
25. the demo version is used the time domain plot will be displayed Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility 12 2 2 Saving a file It is possible to save two new tdm and fdm files with different names selecting File Save as FDM file F4 F4 Function key can be used as a shortcut A dialog box will open to specify the name of the new tdm file Type the tdm file name and then press OK Another dialog box will open to specify the name of the new fdm file Type the fdm file name then press OK and the data will be stored in the new files This function is useful to make additional copies of the output files when different sets of calculation parameters are used Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility File VBT Settings FFT Settings Display Run Help 7 Advanced Measurement Solutions LIM2214 Laser Torque Meter Frequency Domain Utility File VBT Settings FFT Settings Display Run Help Salva in IS Dati de e ES Salva in lo Dati DI de c PS Fe Fe Copia di Yer_ingran2_2048 FDM EN ver_ingran2_1024 TDM E 2 h FDM recenti 14 Ver_ingran2_2048 TDM recent 14 Ver_ingran2_1024 FDM E 4 Ver_ingran2_4096 TDM E la Yer_ingran2_2048 FDM 4 Ver_ingran2_8196 TDM 17 er_ingran2_4096 FDM Desktop 14 2 TDM Desktop 4 Ver_ingran2_8196 FDM 1 2 FDM o o 19 2_ingr2_TRQ_rect FDM Documen
26. ti wr ef Risorse del computer Documenti Pr Risorse del computer n ee FH _ Si amp 1451 Salva come Tom Files y Annulla 1 Salva come FoM Files y Annulla E 2 3 Printing a video page This version of FDM frequency domain software tool does not support neither Print preview nor Print functions To print a VDU page press Print Screen key on PC keyboard This will store the current VDU display in the clipboard Then open a picture management tool such as Microsoft Paint which comes as a standard Windows tool and paste the clipboard Save the image The image can now be printed using the picture management tool itself 2 4 Exit Alt X Selecting the menu File Exit or pressing Alt X keys will exit the utility 13 3 Calculated parameters The program calculates several parameters starting from vibrotorsional input data Whichever input file is selected vbt tdm 7011 the calculation always uses the original vibrotorsional sampling data which are also appended at the end of tdm and of fdm files a Calculated time domain data which can be displayed are Filtered RPM RPM filtered with a moving average filter whose length can be set by the user Unfiltered RPM Instantaneous RPM without moving average filtering Torque Torque calculated starting from filtered RPM and torque pulses stored in the input file Power Power calculated starting from Torque and filtered RPM b C
27. tical markers can be selected by pressing the relevant pushbutton The marker position i set pressing mouse left button Each graph can be zoomed vertically setting the desired value and pressing the Set pushbutton Horizontal zoom is achieved setting both the axis markers and selecting Display axis zoom FS Original display can be restored selecting Display Restore axis F9 For FFT display several options are available a Display spectral lines toggles between envelope and spectral lines display b Display armonics analytic shows the fundamental and higher order armonics in a different colour Cl Display armonic peaks euristic cleans the OC component the floor and all armonic tails and selects spectral lines display d Clean spectrum DC component foor cleans the OC component and the Floor Selecting the menu Help About LTM2214 FDM the general information dialog window is displayed This dialog contains informations regarding the utility revision LTM 2214 Laser Torque Meter Frequency Domain Utility Advanced Measurement Solutions wii AtvancedwleasuramentSalutions com LTM2e214 Laser Torque Meter Frequency Domain Analisys Utility ver 2 00 Copyright c 2008 20012 36
28. used the FFT of the selected input data calculated The program will calculate the sampling frequency from input data and verify the acceptability of the variation ranges of filtered and unfiltered RPM displayed in time 10 domain mode A limited RPM variation range is necessary to ensure sampling frequency constancy If the calculated sampling frequency variation falls outside the allowable range the following dialog boxes will appear indicating that the calculated FFT is not completely reliable YET preprocessor E x Alarm Filtered RPM variation too high 209 1 FFT not reliable BT preprocessor x Warning Unfiltered RPM variation too high gt 6 FFT not reliable At the end of input file preprocessing errors statistics dialog box is displayed The total number of processed samples the number of filtered samples and filtered defective samples percentage is displayed There is no need to worry about high errors percentage above 0 6 0 7 because bad samples are in any case eliminated from input data stream but an excessively high percentage of errors can alter FFT shape and spectrum Advanced Measurement Solutions File processor statistics x Total samples 6893 OF Filtered samples E 0 44934 Then if a registered version of the program is used the FFT plot will be displayed 1 Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility While in case
29. will then create the serial number file LTM2214 FDM SER and switch to full frequency FDM and time TDM domain functionality In case the serial number is not available Demo Version can be selected and the program will switch to Demo mode selecting Registered Version without typing the serial number has the same effect A warning message will appear Click OK to continue Serial check Failure Ei AN Demo version only a reference FFT Function MOT related to input File will be plotted Note In Demo mode full time domain functionality is available while selecting frequency domain functions only a reference graph NOT related to the input data will be plotted So the FFT plots in Demo mode MUST NOT be used In case only time domain functionality is required LTM2214 TDM time domain analysis software tool can be used LTM2214 TDM is a freeware tool downloadable from our web site After these steps the PC will display Advance d Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility Now it is possible to use the program 2 Program operation All LTM2214 FDM utility input and output files are text files with data separated by commars For this reason they can be loaded in a spreadsheet e g Excel for postprocessing printing etc 2 1 Loading an input data file a After starting the program an input data file must be loaded Three alternatives can be selected 1 loading a vibrotor
30. xx Is the maximum overshot allowed in ranging from 0 0 to 1 0 Torque variations beyond the allowed oveshot threshold are considered as spike noise and filtered out An excessively low value of this parameter can filter also valid samples A 0 1 10 value usually works fine Moving average filtering length xx Is the length of the moving average filter The longer the filter length the larger the number of the data that will be smoothed and of the details that will be lost RPM threshold xxx x Is the minimum RPM speed below which the inversion of the sense of rotation is considered as valid An inversion of the sense of rotation which happens at a higher speed is considered as invalid also because it would be mechanically impossible and thus filtered out Zero crossing filter length xx Is the minimum number of samples with inverted sense of rotation after which inversion is considered as valid An inversion of the sense of rotation which lasts for less that this length is considered as invalid and filtered out The tdm file output data structure is quite complex because all intermediate calculation data and instantaneous values are included The following data are stored in tdm files Progr Progressive number of calculation step Tprogr sec Progressive time elapsed from calculation start in seconds Dt sec Incremental time from the previous calculation step in seconds RPMfilt Filtered RPM value 15 TRQf
31. y necessary to set marker 1 to zero to zoom starting from the origin of the X axis zero The number of the spectral line the frequency and the amplitude in absolute value and in dB with respect to the DC value of each marker and their difference is displayed in the lower part of the X axis right panel Moreover in the upper part of the X axis right panel the sampling frequency and the number of samples used in FFT calculation are displayed Sal Advanced Measurement Solutions LTM2214 Laser Torque Meter Frequency Domain Utility _ 5 xj File VBT Settings FFT Settings Display Run Help Y axis TORQUE Hamming Total energy 10659835987 Parseval formula DC value 1904321 0403 Floor level 2542 2003 Even simmetry max error Re 1 4343e 006 Odd simmetry max error Im D 8995e 006 Zoom bm Set Marker 1 Marker 2 Y axis Marker 1 On Off Y axis Marker 2 On Off Ampl Ampl Ampl dB Ampl dB Marker 1 Marker 2 variation Ampl var Ampl var dB X axis Sampling frequency Hz 570 18 Number of samples 2048 Marker 1 r Marker 2 x axis Marker 1 On Off ARS Make a Unit Line 13 Line fi 96 Freq 3 51 Hz Freg 54 56 Hz Ample 1809 94 Ample 78085 Ampl 30 220 Marker 1 Marker 2 variation Lines 183 Ampl var 27795 67 cht lune aaae eael Freg var 50 94 Hz Ampl var 112 137 dB
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