1. What is NOVA?
2. What are the major features of NOVA?
3. Why would I want to buy NOVA instead of a conventional stand-alone spectrum analyzer?
4. Is Snap-Master included with NOVA?
5. How does NOVA relate to Snap-Master?
6. How does NOVA’s Test Templates differ from its Pre-Configured Instruments?
7. What test templates are available in NOVA?
8. What Pre-Configured Instruments are available in NOVA?
9. Can I design my own virtual instruments?
10. Can I use NOVA with HEM Data’s other products, such as DAWN?
11. What hardware models are offered and how do I choose the right one?
12. What if Snap-Master supports a hardware model that is not supported by NOVA, can I use it with NOVA?
13. Can I buy the software separate from the hardware?
14. Does NOVA calibrate sensors?
15. How does NOVA help me perform impact tests?
16. What file formats are supported for modal analysis?
17. Can NOVA be used for post processing data taken with other hardware?
18. Are waterfall plots included?
19. What are waterfall plots?
20. What is a spectrogram and is it included?
21. Can I do 1/3 octave waterfall plots?
22. Can I remove a “slice” from a waterfall plot so I can plot amplitude vs. RPM for a given order?
23. Does NOVA use the FFT or filters for 1/3 octave band analysis?
24. Can I use NOVA’s digital filtering to remove a particular filter range or order?
1. What is NOVA?
NOVA is a PC-based noise and vibration analyzer. It includes a PC with I/O hardware and software. The user may provide his own computer, or alternatively HEM Data will quote a laptop computer.
2. What are the major features of NOVA?
- Compactness & portability for convenient in-vehicle and in-field testing.
- Pre-configured instruments so NOVA comes ready to run several types of noise and vibration tests; this is particularly valuable to the non expert in noise and vibration
- Integrated software and hardware including signal conditioning, working under Windows XP, 2000, NT, Me and 98.
- NOVA has various models that support from 2 to 64 channels, have either 16 of 24 bits of resolution and are priced accordingly.
3. Why would I want to buy NOVA instead of a conventional stand-alone spectrum analyzer?
- The screen display of NOVA is much larger and is more colorful than a stand-alone analyzer.
- NOVA’s Pre-Configured Instruments relieve the user from having to set up the analyzer for the most common noise and vibration (N&V) tests.
- NOVA, with a laptop, is significantly lighter and therefore more portable.
- NOVA offers 8 channels for the same price as a stand-alone analyzer (typically has only 2-4 channels).
- With NOVA, the user is not burdened with the problem of transferring data from the stand-alone analyzer to a PC, since the data is taken and stored directly on your PC.
4. Is Snap-Master included with NOVA?
Yes. Snap-Master is the base upon which NOVA operates. Snap-Master can run without NOVA, but NOVA cannot run without Snap-Master. NOVA purchasers receive the “Snap-Master Complete” model and have full access to Snap-Master if they wish to use it directly.
5. How does NOVA relate to Snap-Master?
This is best demonstrated with an analogy. Think of Snap-Master as a tool similar to a spreadsheet, such as Excel, that can be utilized for a wide variety of applications. Just as Excel can be adapted to specific applications, such as an accounting package, Snap-Master can be adapted to be a noise and vibration analyzer.
Specifically, an entirely new application program was written to be the NOVA interface which is noise and vibration (N&V) specific. All of the Pre-Configured Instruments come with NOVA. The NOVA software communicates with Snap-Master using the Front Panel Library (FPL) toolkit and the 500 DDE (dynamic data exchange) commands that are unique to Snap-Master. This is all transparent to the user. Once the start button is pressed, it is Snap-Master that is doing all of the work. NOVA’s benefit is that it gets you up and running in less time and is much more N&V specific then Snap-Master. NOVA automatically sets up the anti-aliasing filters, does sensor calibration, auto ranges channels, order tracks, assists impact testing, converts sound from dB to dBA, and more.
6. How does NOVA’s Test Templates differ from its Pre-Configured Instruments?
Test Templates are function specific, such as compute an auto power spectrum or coherence function. The test templates require that all input channels be computed identically. Test Templates let NOVA operate similarly to conventional spectrum analyzers.
The Pre-Configured Instruments are application specific, such as: order tracking, sound metering, or impact testing. A Pre-Configured Instrument can treat each channel differently and is much more flexible. Pre-Configured Instruments exceed the capabilities of conventional analyzers. NOVA comes with several pre-configured instruments that may be exactly what you need. If they need to be modified, you can adapt them with Snap-Master (without writing code), or you can ask HEM Data to quote the work required to meet your specific application.
7. What test templates are available in NOVA?
Linear Spectrum (FFT), auto power and auto power spectral density, cross power and cross power spectral density, coherence, impedance, coherent output power, oscilloscope, high speed data storage, replay of data from disk.
8. What Pre-Configured Instruments are available in NOVA?
- Frequency response functions using impact testing for modal analysis, dynamic stiffness, etc.
- Real-time order tracking with waterfall plots
- Sound metering with 1/3 octave band analysis
- Data logging with the ability to determine the frequency spectrum over a user specified range of data
- Pass/fail detection for new parts of predictive maintenance
9. Can I design my own virtual instruments?
Yes. Many examples are given which can be modified, or the user can start from scratch. The best of various instruments can be combined to meet specific applications. You would be working in Snap-Master to do this work.
10. Can I use NOVA with HEM Data’s other products, such as DAWN?
Yes. This is a major advantage for noise and vibration testing in automotive vehicle testing. Since you have access to all of the sensors already on the vehicle, you only need to add sensors that are missing, such as microphones or accelerometers. DAWN is an excellent source of information on the vehicles operating conditions while performing N&V tests.
11. What hardware models are offered and how do I choose the right one?
NOVA currently has three models. It is expected that more models will be available in the future. Check with HEM Data for the latest models supported if the current models do not meet your needs. Please refer to the specification sheet comparing these models. The following is a brief summary contrasting the current models supported.
NOVA-AS
This is a 24 bit system with 2-20 channels that has excellent specifications. It has up to 4 tach channels to measure speed and angle and is excellent for order tracking. This system has signal conditioning for accelerometers; otherwise voltage inputs must be provided for other types of sensor using external signal conditioning, if required. This model is specifically designed for N&V testing. Includes overload indicators.
NOVA-WB8
This is a versatile 8 to 64 channel system that has optional signal conditioning modules for a wide variety of sensors such as strain, current, frequency, temperature, etc., so it is well suited for N&V testing while also acquiring other types of sensor inputs. It has the advantage of a 1 MHz aggregate throughput. For one channel it is 1 MHz, 2 channels is 500 kHz, 4 channels is 250 kHz, etc.
NOVA-DB2
This is a 2 channel system for those who only need a low channel count, and a price to match.
12. What if Snap-Master supports a hardware model that is not supported by NOVA, can I use it with NOVA?
The test templates will only work with NOVA supported hardware. However, for Snap-Master supported hardware, the Pre-Configured Instruments should work in NOVA once they are set-up in Snap-Master.
13. Can I buy the software separate from the hardware?
Yes. If you already own the hardware that NOVA supports, you only need to purchase the software. If you already own the hardware and Snap-Master, then you only need to purchase NOVA. Click here for the latest models.
14. Does NOVA calibrate sensors?
Yes. Not only does NOVA calibrate the sensor but it automatically updates the sensor database with the latest successful calibration. It will also provide a pass or fail decision on the calibration depending on the accuracy required by the user.
15. How does NOVA help me perform impact tests?
Since impact testing is a very powerful test technique but is fraught with potential problems, a great deal of effort was made to assist the user to perform impact testing correctly. For example, double hits, underloads or overloads are detected. If an improper impact is detected, then it is not included in the averaged data, thereby preventing contamination of good data. Also, the user has direct feedback on each impact. In addition, if the user needs more detail regarding the information that produced the transfer function, plots of the hammer spectrum (to select hammer size and tip), the response spectrum (to check accelerometer model, mounting and positioning), and the windows used for the FFT analysis, it is available with a simple mouse click to a new display page.
16. What file formats are supported for modal analysis?
StarModal by Spectral Dynamics and ME’scope by Vibrant are supported.
17. Can NOVA be used for post processing data taken with other hardware?
Tape recorders by TEAC and Sony produce a Snap-Master binary data file format that can read by NOVA, as well as Optim Electronics’ MegaDec.
18. Are waterfall plots included?
This is an option to the base unit.
19. What are waterfall plots?
A waterfall plot is a three dimensional representation of your data. Typical displays include frequency on the x-axis, amplitude on the y-axis, and time in the z-axis. Another popular form when used in conjunction with order tracking is to have orders on the x-axis, amplitude on the y-axis, and RPM on the z-axis.
20. What is a spectrogram and is it included?
A spectrogram is another method of showing 3D data. It is similar to viewing a waterfall plot from the top so that amplitude is represented by color or shades of gray. This is similar to a Campbell diagram and a sonogram. Spectrograms are included with the waterfall option.
21. Can I do 1/3 octave waterfall plots?
Yes.
22. Can I remove a “slice” from a waterfall plot so I can plot amplitude vs. RPM for a given order?
Yes you can plot amplitude vs. RPM or time, and amplitude vs. Order or frequency.
23. Does NOVA use the FFT or filters for 1/3 octave band analysis?
NOVA could do either one but the FFT is the faster and a more practical approach for NOVA. NOVA will give the correct answer for overall sound level and will group the FFT results into bands such as octave, 1/3 octave, 1/5, 1/8, 1/12 octave. The user should be aware that NOVA does not claim to meet ANSI standards. Conventional analyzers use filters that inherently have rolloff characteristics. So for a given band, an FFT analyzer will produce a slightly different result. Therefore, if you are comparing your results to a conventional sound meter, or to published standards, you should be aware of the differences. If you are comparing your own tests for various test conditions, then NOVA is well suited for this. And again, the overall noise level is the same for both approaches.
24. Can I use NOVA’s digital filtering to remove a particular filter range or order?
Yes, you can remove both a frequency range or an order with NOVA’s band reject filter. You can use either a FIR or IIR filter model but we recommend a FIR filter since it does not introduce a phase shift in the results. You can remove a given order from order tracked data and a given frequency from all other data.