PULSE Reflex Basic Order Analysis Type 8704
PULSE Reflex Basic Order Analysis Type 8704 adds the speed dimension to FFT or CPB analysis. Typically the speed quantity is the rotational speed (RPM) of an engine or other type of rotating machinery. By mapping instantaneous spectra to RPM instead of time, the harmonics which relate to orders (multiples of rotation frequency) are straightened out and are easier to interpret. These orders can be extracted from the spectral map as amplitude versus RPM functions.
Uses
- Basic rotating machinery analysis
- Quick qualitative assessment of order content
- Determination of critical speeds and resonances
- Signature analysis of machines with rotating components
- Pre-study for tracked order analysis
- Vehicle NVH benchmarking
Features
- Fixed frequency bandwidth order analysis
- Order analysis based on frequency domain spectra
- Graphical order extraction tool
- Tachometer dropout/spurious pulse correction
- Tachometer smoothing
- Tachometer pulse train synthesis from RPM profile
- Autotracker - RPM profile and tachometer synthesis from response signals
The process is illustrated below, where a run-up test is analyzed for frequency and order content. Note that tracked order analysis is available with PULSE Reflex Core Advanced Order Analysis Type 8705.
An RPM profile for a vehicle run-up test is extracted from a recorded tachometer pulse time history.
A display of spectra versus time shows clear harmonics which have a similar shape to the RPM profile. The order cursor follows this shape, enabling order number, frequency and amplitude information to be extracted for interesting features like this 6th order peak.
The same spectral data can be displayed versus RPM, and now the order lines become straight, making it easier to understand speed related responses.
The 6th order is now shown as a function of RPM, showing the peak of interest at just over 4000 RPM.
These displays can be shown together in the same display page, all cursors synchronised, for reporting purposes.
