Changing Frequency Span

AGILENT 35670A

Supplemental Operator’s Guide

Changing frequency span or resolution affects three important parameters in hammer testing which must be changed to correspond to the new time record length: Trigger Delay, Force Window Width, and Response Window Decay Time. The following relationship between the parameters can be used as a guideline:

T= N (1024.F )

Where T is the time record length in seconds, N is the resolution in lines, and F is the frequency span in Hz.

Delay = 01.(T)

ForceWidth = T 7

ExponentialDecay = T 4

When the frequency span is halved, the Time Record length doubles, as does the Delay time, Force Width, and Exponential Decay. All three parameters should change with the inverse of the change in frequency span.

Page 35

Image 35

Agilent Technologies Agilent 35670A manual Changing Frequency Span, Delay = 01.T ForceWidth = T ExponentialDecay = T

Agilent 35670A specifications

Agilent Technologies Agilent 35670A is a prominent and versatile dynamic signal analyzer designed for various applications in vibration testing, structural analysis, and noise measurement. Engineered to meet the rigorous demands of engineers and researchers, the 35670A is especially valued for its advanced features and functionalities that facilitate detailed analysis and troubleshooting.

One of the primary features of the Agilent 35670A is its ability to perform real-time signal analysis. The instrument is equipped with a powerful processing engine that handles large amounts of data efficiently, providing fast and accurate results. This real-time capability is critical for dynamic testing applications, allowing engineers to monitor and analyze signals as they occur, thereby facilitating quicker decision-making and problem identification.

The Agilent 35670A employs advanced Fast Fourier Transform (FFT) algorithms, which provide high-resolution spectral analysis. This feature is essential for engineers needing to identify frequency components in complex signals, making it particularly useful in the fields of acoustics and mechanical engineering. The analyzer supports various types of measurements, such as magnitude and phase, enabling users to delve deeply into their data.

Another key technology embedded in the Agilent 35670A is its ability to perform multi-channel measurements. The instrument can connect to a variety of external sensors and testing devices, making it a flexible choice for users who need to analyze multiple signals simultaneously. This multi-channel feature is particularly advantageous in automotive testing, aerospace applications, and structural health monitoring.

The device also comes equipped with a user-friendly graphical interface, enhancing the overall user experience. The interface facilitates easy navigation and access to various measurement modes, settings, and data visualizations. Additionally, the Agilent 35670A supports automated measurements, allowing users to save time and reduce human error in repetitive testing scenarios.

Furthermore, the Agilent 35670A offers extensive connectivity options, including GPIB and USB interfaces, making it easy to integrate into existing laboratory setups and automated testing systems. This flexibility ensures that users can adapt the analyzer to their specific needs and workflow processes.

In summary, the Agilent 35670A stands out as a sophisticated dynamic signal analyzer that combines advanced signal processing technologies with user-friendly features. Its real-time analysis, multi-channel capabilities, and extensive connectivity options make it an invaluable tool for professionals in various engineering fields, dedicated to achieving precision in their analyses and solutions.

Contents

ÃSeattle Sound and Vibration, inc David ForrestSeattle Sound and Vibration, inc Print Date December Supplemental Operator’s Guide Agilent 35670A Hammer Test Setup Without a Force Transducer Recalling Trace Data from 3.5 Disk or NON-VOLATILE Memory Typical Display After Turn-on Sequence Turning On the Agilent 35670A Window Measurement State After Turn-on Using Transducers with External Preamplifiers Using ICP-Type Transducers with the Agilent 35670ATo set up Channel 1 for an ICP-type transducer To set up Channel 2 for an ICP transducer Specifying Transducer Sensitivity and Units Press Xdcr Unit CH2 Setup softkey F8Press Xdcr Unit CH1 Setup softkey F8 Selecting Frequency Span Measuring a Single Channel Power Spectrum DisplacementSetting Up Transducer Units for Displacement Selecting Single Channel Operation To automatically scale the display to fit the data CH4 Quantifying Power Spectrum Results To return to baseband measurements Frequency Zooming to Increase ResolutionImproving Measurement Results To set a new, lower span Enter softkey F1 Averaging to Reduce Measurement Variance AVG Measuring a Single Channel Time Waveform Then set the instrument mode to single channel as above Then to arm a single time record Using Manual Arm to Capture a Single Time WaveformSelecting Time Record Length Displaying Time Waveforms Analyzer should show in highlighted text above the trace Event TriggeringTo start the data acquisition CH4 Quantifying Time Trace Results Selecting Dual Channel Operation Presetting the AnalyzerDisplaying Dual-Channel Power Spectrum Measurements Measuring Dual Channel Spectra To acquire dual channel spectra Using Markers with Dual Channel Measurements Coupled Markers with Peak Tracking Coupled Markers Dual Channel Averaging To set up the same fixed range on all channelsImproving Dual Channel Measurement Results Avg Type RMS Number Displaying Dual Time Waveforms Measuring Dual Channel Time WaveformsThis always returns the analyzer to dual-channel operation Triggering a Dual-Channel Time Measurement Arming Dual Channel Time Measurements FFT Trigger Delay Measuring Dual Channel Spectra and Time Waveforms Using Markers with Dual Channel Time Measurements 0Hz CH2 Pwr Spec X60 Y88.5405 mVrms 100 MVrms LogMag UVrms Set up the force transducer parameters as follows Modal Testing Using a Hammer and AccelerometerSetting Up the Transducer Parameters Wait for the analyzer to finish its preset routine Specifying Trigger Parameters Setting Up Input RangeUse CH* Auto UP only as the autorange routine as follows Choosing a Preliminary Frequency Span Press the Windowed Time CH 2 softkey F5 Setting Up Time DisplaysNow to check that the trigger parameters are correct Press the Windowed Time CH 1 softkey F5 FFT Using Force/Response Windows Averaging Press the Force Expo Setup softkey F6To view the effects of theForce/Response window Displaying Hammer Test Results FFT To start taking measurements Changing Frequency Span Delay = 01.T ForceWidth = T ExponentialDecay = T Setting Up the Hammer Test Without a Force Transducer Hammer Test Setup Without a Force Transducer Prepare the order results list as follows Order Domain Results in List ModePrepare the order display as follows To start taking measurements Press the UPPR/LOWR FRNT/BACK softkey F5 Comparing Two-Channel Real-Time Spectra with Recalled DataSelecting Measurement Parameters Displaying Dual-Channel Spectra Compared with Recalled Data Into D2 softkey F2 Recalling the Spectra from DiskRecalling the Spectra from Non-Volatile RAM Into D1 softkey F1 Press the Y PER DIV Decades softkey F6 Scaling the Displays Using Markers to Compare Press the PWR Spec Channel 1 softkey F3 Setting Up the Waterfall DisplayContinuing to set up a waterfall display Waterfall Spectra at Time Intervals Using Slice Markers with Waterfall Data Setting Up Time Step Arm Press the Save and Disp Data softkey F5 Then specify the total number of spectra to be collectedPress the Waterfall Markers softkey F5 Specifying the Start RPM Setting Up the TachometerThis starts the measurement when 1000 RPM Waterfall Spectra at RPM Intervals Scaling the Display Starting and Pausing a Measurement Properly Scaled, RPM Triggered Waterfall Display Accelerometer Polarity Two-Channel Absolute and Differential Amplitude Measurement Measuring Amplitudes, Differential Amplitude, and Phase Set up triggering on Channel 1 to 5% of range For accelerometers with opposite polarity Set up the Agilent 35670AUsing a Math Function to Measure Differential Motion For accelerometers with the same polarity Press the PWR Spec Channel 2 softkey F3 Set up displaySet up trace coordinates as peak-to-peak mil Put the math function of the differential motion in Trace c Start measurement Measuring Frequency Response with the Agilent 35670A Measuring Frequency Response Using Impact ExcitationMeasuring Frequency Response Using Broadband Excitation Set up the shaker Enter Channel 2 input parameters Preset the Agilent 35670AConnect the transducers Enter Channel 1 input parameters Press the Freq Resp 2 / 1 softkey F6 Set up display parametersSupplemental Operator’s Guide Choose measurement parameters Viewing Frequency Response Results with a Nyquist Diagram Set up the trigger Viewing Results Using Real and Imaginary Traces Assessing Measurement Quality MV/EU softkey F2 Set up transducer parameters for a 10 mV/g accelerometerSet up Trace B to measure velocity in inch/s 0-pk Two Spectral Traces Showing Mils and Ips while EU is G Agilent 35670A Specify measurement parameters Set up display format to measure peak amplitudePeak Hold During a Machine Run-up and Coast-Down Press the yellow Pause/Cont hardkey and examine results When the run-up and run-down is completed Press the Unfilterd Time CH 1 softkey F6 Using an External Trigger for Time AveragingSpecify User Levels for Triggering Characterizing the External Trigger Set up a non-TTL trigger as follows Characterize the Trigger SignalSetting Up External Trigger Measuring Time Averaged Spectrums with External Triggering Set up measurement parameters Saving Trace to 3.5 Disk Confirming Contents of 3.5 Disk File Saving Trace to Non-Volatile RAM NV-RAM Confirming Contents of NV-RAM Recall Trace Data from Non-Volatile RAM NV-RAM Recalling Trace Data From 3.5 Disk or Non-Volatile MemoryRecall Trace From 3.5 Disk Into D2 softkey F2 Plotting the Display Plotting and Printing Trace DataGenerating Output with the Agilent 35670A Enter a plot title if desired Print over Parallel Interface to Raster Device Check the Plot/Print DestinationPlot the Trace Printing the Display It should now be an import option Installing the MS Word HP-GL Graphics Import FilterImporting Plots into Microsoft Word Determining if MS Word Has HP-GL Graphics Import Filter Plot to file P1.HGL Plot to a File Using the Agilent 35670A Precautions to Prevent Loss of Data Running a Single Calibration Test on CommandReturning the Agilent 35670A to a Preset Condition Specify an averaged measurement Measuring Acceleration, Displaying DisplacementPress the Front END CH1 Setup softkey F7 Transducer Unit Conversion with the Agilent 35670A Converting Frequency Response Units to Compliance Math Functions and Xdcr Unit Convert Press the Constant K1-K5 softkey F3 Now display the function F1 on Trace B Agilent 35670A Agilent 35670A Section Measuring a Single Channel Spectrum Section Measuring Frequency Response with the Agilent 35670A