Guralp Systems CMG-3ESPCD - Manual (Page 46)

CMG-3ESPCD Digital Broadband Seismometer Using Scream!
trigger. The Ratio column determines by what factor the STA and LTA must
differ for the trigger to be passed. Finding the ratio most suited to your needs
is best done by experiment. Too high a value will result in events being
missed, while too low a value will result in spurious non-seismic noise
triggering the system. Like the averages, their ratio is continuously
recalculated for all components. Note that none of the boxes are allowed to be
empty, and so you will need to enter the new value before removing the old
one. Alternatively, you can use the up and down cursor keys to change the
values.
MAN-C3E-0002 46 Issue B - November 2013