Operating Instructions
8
NOTE: Most of these statistics are self explanatory, but the following two
statistics may require a bit more explanation:
▪ Extreme Spread(ES)
To get the Extreme Spread, the lowest velocity (for the current string) is
subtracted from the highest velocity.
▪ Standard Deviation(Sd)
Consider an example to illustrate the meaning of standard deviation. If
for example you have a standard deviation of 10 fps with an average
velocity of 1000, 68% of the shots you re will fall within 990 to 1010 fps.
If you double the 10 fps standard deviation to 20 fps, 95.4% of the
velocities will fall within 980 to 1020 fps. The more shots you re, the
more accurate the standard deviation. A minimum of 5 shots is needed
and more would be desirable.
TIP: To quickly switch from shot velocities to statistics with large shot
strings, and vice versa, hold down the “Review” button. After a short time,
the unit will switch directly from velocities to the rst statistic, or statistics
to the most recent shot velocity.
Delete Shot
While positioned on a velocity, this current velocity can be deleted by
pressing the “Delete Shot” button. When you press this button, the
ProChrono Digital will delete the currently displayed velocity, renumber
all the shot velocities above it in the string, and reposition the display
to the last velocity. It will redisplay the velocity number, which has been
decreased by 1 due to the deletion just performed. Statistics will be
recalculated minus the deleted shot(s). This operation is not reversible.
Delete String
If desired, you may delete all the velocities in the current shot string at
once by pressing the “Delete String” button. This operation is not reversible.
Redisplay
With so many velocities and statistics available for display, it is easy to
forget what you are looking at. The”Redisplay” button will briey show
you either the string and shot number, or the string and statistic ID. This
allows you to get a second look at the data without scrolling through this
string again.