http://blog.prosig.com Telling you what you really need to know about noise & vibration measurement Thu, 09 Sep 2010 09:46:15 +0000 en hourly 1 http://wordpress.org/?v=3.0.1 http://blog.prosig.com/2006/01/12/torsional-vibration-tacho-pulses-and-aliasing/ http://blog.prosig.com/2006/01/12/torsional-vibration-tacho-pulses-and-aliasing/#comments Thu, 12 Jan 2006 15:44:34 +0000 Dr Colin Mercer http://blog.prosig.com/2006/01/12/torsional-vibration-tacho-pulses-and-aliasing/ With shafts, gears and the like, the general method of determining the rotational speed is to use some form of tachometer or shaft encoder. These give out a [...]]]> http://blog.prosig.com/2006/01/12/torsional-vibration-tacho-pulses-and-aliasing/feed/ 2 http://blog.prosig.com/2005/10/19/analyzing-shaft-twist-and-repairing-damaged-tachos/ http://blog.prosig.com/2005/10/19/analyzing-shaft-twist-and-repairing-damaged-tachos/#comments Wed, 19 Oct 2005 09:22:40 +0000 Dr Colin Mercer http://blog.prosig.com/2005/10/19/analyzing-shaft-twist-and-repairing-damaged-tachos/ A shaft has been instrumented with two shaft encoders, one at each end. Each shaft encoder gives out a once/rev pulse and a 720 pulses/rev signal. Each signal was digitised at 500,000 samples/second. The objective is to measure the twist in the shaft and analyze into orders. The test stand was already equipped with a data [...]]]> http://blog.prosig.com/2005/10/19/analyzing-shaft-twist-and-repairing-damaged-tachos/feed/ 1 http://blog.prosig.com/2002/05/15/torsional-vibration-example/ http://blog.prosig.com/2002/05/15/torsional-vibration-example/#comments Wed, 15 May 2002 10:10:09 +0000 Dr Colin Mercer http://blog.prosig.com/2002/05/15/torsional-vibration-example/ The measurement of the twist angle between two points along a shaft or through a gear train may be derived from a pair of tacho signals, one at each end of the shaft. Typically the tacho signals would be derived from gear teeth giving a known number [...]]]> http://blog.prosig.com/2002/05/15/torsional-vibration-example/feed/ 3