Section  4  —  Measurement  Types  and  their  Uses 
65 
Recommendations for Cross Channel Phase 
 
When  conducting  a  cross  channel  phase  analysis,  we  recommend  you: 
1.  Determine  the  exact  frequency  of  interest.  To  do  this,  you can  use 
spectra  to  identify  high  amplitude  peaks  at  specific  frequencies. 
2.  Position  the  channel  1  sensor  in  a  location  which  has  high vibration 
at  this  frequency.  Do  NOT  move  this  sensor  once  testing  has  started. 
3.  Try  out  different  locations  with  the  channel  2  sensor,  noting  the 
phase  and  amplitude  relationships  compared  to  the  fixed channel  1 
position. 
4.  Repeat  steps  2  and  3  at  any  other  locations  of  interest.