PASCO Xplorer-GLX Users’ Guide - Manual (Page 68)

62 T i m i n g S c r e e n
Ti m i n g S c r e e n
Use the Timing screen to set up measurements made with photogates, Smart Pul-
leys and other switch- or counting-type sensors.
To Open the Timing Screen
The Timing screen usually launches automatically when you connect a switch- or
counting-type digital sensor to the GLX through a Photogate Port or a Digital
Adapter.
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If a timer for a sensor has already been set up, the Timing screen will not auto-
matically launch when that sensor is plugged in. To manually open the Timing
screen from the Home Screen, do one of the following:
use the arrow keys to highlight the Timing icon and press ; or
click the Timing icon.
Theory of Timing
Certain digital sensors connected to the GLX through a Digital Adapter or Photo-
gate Port operate differently from most other sensors. Rather than collecting data
at a constant rate, they send a signal to the GLX only when an event happens. For
instance:
• when a photogate switches from being blocked to unblocked, or vice-versa;
• when the spoke of a pulley enters or exits a photogate; or
• when a nuclear sensor detects a particle.
The GLX can be configured to measure the time span of a particular sequence of
events. Examples of sequences include:
• blocked-unblocked, or “time-in-gate;”
• blocked-blocked, or “time-between-gates;” and
• blocked-blocked-blocked, used to measure the period of a pendulum.
The “blocked” event occurs when a photogate switches from being
unblocked to blocked. The “unblocked” event occurs when a photogate
switches from being blocked to unblocked.
Whenever the specified sequence occurs, the GLX records the time span of the
sequence as a data point. It also records the time at which the sequence occurred,
The Timing Screen
13 Photogate Port is PASCO part
PS-2123A. Digital Adapter is PASCO
part PS-2159.
The Timing icon on
the Home Screen