Signal Acquisition for NVH and more...

MajX-DSA is an easy to use NVH measurement and analysis tool designed to access to the rich feature set available in the National Instruments Sound & Vibration toolset. While offering flexibility and power, MajX-DSA is designed to simplify the user experience making it ideal for those who want to get to the data fast with minimal exposure to complex configuration procedures.

Use MajX-DSA to:

• Implement a hardware solution scaled to your  signal configuration through a variety of  Deployment Options

• Capture data files manually, or utilize a remote digital trigger to achieve a fully autonomous data acquisition capability

• Mix signal types including high speed NVH signals, generic analog signals, counters for high resolution speed and torsion, and digital event markers

• Perform single and dual plane balancing

• Perform common NVH signal processing tasks such as frequency and order domain spectrum analysis, order analysis, impact testing and time/frequency analysis for impulsive events, harmonics and resonance behaviors

• Save data in NI's TDMS format, and easily export processed results to text files

 

Spectrum Analysis

Use MajX DSA to compute frequency and order domain spectra. View up to 8 spectra at a time while  interactively scrolling through the file using the file position slider.

Frequency Domain Spectra can be analyzed with a few standard controls	Order domain spectra are derived from data re-sampled against an available tachometer signal

In addition to power spectra, also compute frequency response function magnitude, phase, coherence and coherent output power. Hanning and flatop windows are available as are, linear and exponential averaging, pre-filtering and A-weighting for acoustic signals. Linear, power and PSD unit scaling is available, and advanced cursor functions provide band power computations as well as single and double sided harmonic series annotation.

 

Time/Frequency

View dynamic signals in the time/frequency domain to explore harmonic interaction with resonance, identify impulsive events, and extract and analyze discrete orders vs time or speed.

The time/frequency graph shows the overlapped short-time FFT and a graphical cursor keyed to a shaft speed reference for order selection	Explore harmonically related features to uncover dynamic effects which govern overall energy levels vs. time or speed

 

 

 

Impact Testing

The dynamic response to a short duration impulse can be used to define the

Typical hammer selection used for impact testing

frequency response function (FRF) of a structure. MajX DSA supports the impact method where an instrumented hammer is used to impart measured force while transducers such as accelerometers are used to measure the response.

 

Acquire FRF's from all response channels simultaneously and view Mag/Phase/Re/Im or Coherence of up to four FRF's at once.

• pre-triggered preview of impact and response

• Force/exponential windowing

• Magnitude/phase, real/imag coordinates

• Coherence display

• Freeform and geometry based    naming (component, subcomponent, point, direction) with text export

 

 

Balancing

Balance rotating machinery in one or two planes with the balancing option for MajX DSA.

A tablet PC with the USB 9234 and  MajX DSA  excels as a portable balancing tool

• Intuitive step-by-step approach through a menu based balancing sequence

• Utilize an over-determined sensor array (up to seven response transducers) to achieve a global best-fit balance solution

• View the magnitude and phase response of each sensor in a narrowband spectrum to assess signal strength, repeatability and sensitivity to trial weight addition.

• Interactively choose the most responsive sensor set to achieve the optimal balance

• Compute trial weight and balance weight splits

• Store the balance model and perform trim runs as necessary

 

 

Deployment Options

 

Compact DAQ NI's c-series modules  operate with USB2.0 single sleeve carrier, or build a larger system using the externally powered 8 slot chassis. details

PXI MajX-DSA can take full advantage of the powerful new embedded CPU's from  NI an allow you build a powerful multi-channel system. details