Motion Sensor II
012-06757B
2
Equipment
Included:
• PASCO CI-6742 Motion Sensor II
• detachable cable with two color-coded phone
plugs
Additional Equipment Required:
• computer and ScienceWorkshop 500, 700, or
750 Interface
or
• scientific calculator and sensor interface
(Texas Instruments or Casio) and cable
(PASCO part no. 514-06862)
or
• ULI Interface and cable (PASCO part no.
514-06933)
Using the Motion Sensor II
1. Insert the yellow phone plug into digital channel
1 (or 1, 2, or 3 for ScienceWorkshop series 700
and 750 interfaces). Insert the black phone plug
into digital channel 2 (or 2, 3, or 4 for Science
Workshop series 700 and 750 interfaces).
Note: The Motion Sensor can be connected to
any two adjacent digital channels on the
interface, with the yellow plug in the channel
with the lower number. The yellow plug carries
the transmit signal from the ScienceWorkshop
interface to the sensor, and the black plug
carries the return, echo signal, from the sensor
to the Science Workshop interface.
2. Run the ScienceWorkshop program. In the
Experiment Setup window, set up the
ScienceWorkshop interface and sensor so the
Motion Sensor is connected to the correct
digital channels of the interface.
Note: You can set up the Motion Sensor II in
ScienceWorkshop program (2.x series) by
dragging the digital plug icon to channel 1 if
the phone plugs are inserted into channels 1
and 2 on the interface box, or by double-
clicking the Motion Sensor icon in the list of
sensors (3.x series).
Note: With the 700 and 750 interfaces, two
Motion Sensors may be used at the same time.
3. Set the Narrow/Standard (Std.) switch based
on your application. For experiments that
involve sensing distances of 2 meters or less
with highly reflective targets (such as a typical
Dynamics Track experiment), set the switch to
Narrow. This setting reduces sensitivity to
false targets near the track and sensitivity to
air track noise. For experiments that involve
longer distances or poorly reflecting targets
(such as match-graph experiments), set the
switch to Std.
Note: When using the Std. switch setting it may
be necessary to tilt the sensor up 5-10 degrees
to avoid seeing reflections from a table
surface or the front of the housing as a target.
4. For most experiments, the internal calibration
in ScienceWorkshop will be adequate.
However for maximum accuracy the Motion
Sensor II may be calibrated as follows:
a. Double-click on the Motion Sensor icon to
open the Digital Sensor Setup dialog box.
b. Aim the Motion Sensor II at a stationary
target one meter away (the default calibration
distance).
c. Click Calibrate. The Motion Sensor II will
click a few times per second during the
calibration process. The program will
calculate the speed of sound based on the
default calibration distance (one meter) and
the round trip time of the pulses and echoes.
Note: If the Motion Sensor does not detect a
target, the Interface may stop trying to
calibrate. Should this occur, realign the target
of the sensor and try again.
5. Change the trigger rate (if necessary) by
clicking the up/down arrows to the right of the
Trigger Rate pop-up menu, or click the pop-
up menu and select the Trigger Rate you
need. (The Trigger Rate may need to be
increased from the default 20 Hz for fast
events like collisions or free-fall experiments
in order to achieve the necessary resolution.)
