Difference between revisions of "NVGate Torsional"

On reciprocating machinery (diesel engine, pump) or any acyclic rotating devices (generator,compressor), the cause of torsional vibrations often comes from the non-homogeneity of the angular speed. The analysis of the instantaneous angular speed inside each shaft revolution provides the essential information. Such analysis is helpful for vibrations reduction during prototyping or even for source identification while doing service diagnostics.<br>

The common way to measure instantaneous velocity is to install a coding wheel or a rotary encoder on the shaft. The rate of pulse delivered by such device is directly proportional to the RPM speed during the last pulse interval. On most vibration analysers, this type of measurement needs a specific conditioner(usually optional external boxes) which transforms the pulses train into a DC voltage proportional to the RPM. These conditioner devices are expensive, lead to more cable and are often limited to 2 probes and so on. But the main inconvenience is the phase error they introduce due to their internal response time.<br>

This option transforms each external Synch input into a frequency to RPM converter (allows handling up to 6 torsional/acyclic inputs at a time). This integrated converter benefits of the high accuracy of the 3-Series analysers Ext. synch inputs (over sampled up to 6.4 MHz). As a matter of fact the sampling of such pulse rate must be very accurate in order to avoid speed jitter on the result.

The IVC (Instantaneous Voltage Converter) option features the following main specifications:<br>

· Available filters: HighPass, LowPass; BandPass, StopBand, Integrator (single or double) and differentiator<br>