1. 
   Vectorscope
   An instrument similar to an oscilloscope, that is used to check and/or align amplitude and phase of the three colour signals (RGB). It has a circular, rather than rectangular screen, to show the phase angles of the component colours.
   Found op http://www.zoo.co.uk/~z0001325/Glossary.html
   
   
2. 
   vectorscope
   vectorscope A special type of oscilloscope used in both audio and video applications. Most modern waveform monitors include vectorscope functionality built in; and many allow the two modes to be displayed side-by-side. The combined device is typically referred to as a waveform monitor. Stand-alone ...
   Found op http://www.wordinfo.info/words/index/info/view_unit/3414/
   
   
3. 
   Vectorscope
   A vectorscope is a special type of oscilloscope used in both audio and video applications. Whereas an oscilloscope or waveform monitor normally displays a plot of signal vs. time, a vectorscope displays an X-Y plot of two signals, which can reveal details about the relationship between these two si...
   Found op http://en.wikipedia.org/wiki/Vectorscope
   
   

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