Instructions for Phasing up the Data-System's Demodulation

  • It will be assumed that the reader knows how to phase up a lock-in
  • Setting the phase of the data-system's demodulation can be tricky. The status/control window in the "sparo" program (running on the Mac called "gnu") is where the phase is usually set. Unfortunately, the convenient little buttons that allow one to change phase by 180 deg. or 90 deg. do *not* affect the phase that is displayed in the status/control window. However, they *do* affect the actual phase used for the lock-in demodulation.
  • To see the value of the actual phase (that is used for the data-system's lock-in demodulation) one has to open up the "phases" window and then furthermore, one has to set the display mode in this window to "numbers" rather than the graphical display. The display mode is set by clicking on one of two little buttons that lie within that phase window.
  • The phase is also saved to data file, as is the quadrature data. So the phase can be checked "after the fact".