Vernier Original LabQuest - Manual (Page 12)

LabQuest Reference
10
• The Number of samples exceeds 2000 at rates faster than 80 kHz. The number of
samples always includes the pre-trigger samples.
Mode: Triggering
Triggering is only available in Time Based mode. When enabled, LabQuest will wait for a
trigger condition to be met before beginning data collection. For example, you might wait to
collect data until a force sensor is rising over 2 N. The sensor name, the level, and the
direction of change (increasing or decreasing) can all be set here. A limited number of points
before the trigger condition is met can also be saved with your data.
Mode: Advanced Settings
The Advanced field allows you to enable Oversampling, which samples the sensor at a rate
higher than the number of samples per second you set, and then averages those readings.
Also, you can enable Repeat mode, which starts a new run as soon as the current run has
ended.
Mode: Events with Entry
Sometimes experiments do not depend on time, but
depend on the setting of some other quantity. For
example, in a Boyle’s law experiment one wants to
know the pressure as a function of the volume of gas.
In this case the Events with Entry mode is used. When
setting up this mode, you can enter a name and units
for the entry column, such as “Volume.” Scroll down to
see the option “Average over 10 seconds.” This setting
will cause LabQuest to take a ten-second average for
each reading, which is particularly useful for water
quality studies. Once data collection is started with the
collect button, a Keep button appears. Tap the Keep
button to record the sensor value, and then LabQuest
will prompt for the Entry value. Sensor values are
plotted versus the Entry values. No time information is
recorded in Events with Entry mode.
Mode: Selected Events
Selected Events is like Events with Entry, except that
entries of 1, 2, 3… are entered automatically for you. No time information is recorded in
Selected Events mode.
Mode: Photogate Timing
Photogates require a different set of timing options. When a photogate is detected,
LabQuest switches to Photogate Timing mode. Within Photogate Timing there are
additional modes.
End data collection settings in Photogate Timing have two choices: either the collection runs
until the user taps stop, or the collection can be set to end after a defined number of events.
A block/unblock pair counts as two events.