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Appendix: Using the PASCO photogate
To set up the photogate
1. Attach the photogate to the Science Workshop interface box.
2. When DataStudio starts up, it might ask what you would like to do. If so, choose “Create
Experiment”. If it doesn’t ask, or if you do not see a picture of the “Science Workshop 750”
interface, click on “Setup” button, which should bring up the “Experiment Setup” dialog box.
[If the motion sensor or some other USB sensor (what PASCO calls a PASPORT sensor) is also
connected to the computer, it may not recognize the science workshop interface; Click on
“Choose Interface…” (within the “Experiment Setup” dialog box) and choose “SW750”]
3. On the picture of the “Science Workshop 750” interface on the computer screen, click on each
digital channel location that a sensor is plugged into. This should bring up a list of possible
sensors each time. Choose the correct icon from the list (the photogate is called “photogate;”
the landing pad is called “time of flight”).
To set up timer
To tell the computer how to measure a time interval, click on the “Timers…” button.
1. In the “Timing Sequence Choices” area, there should be images of each photogate (and landing
pad, if used) connected to the interface. Click on the small box next to the photogate you want
to use to start the timer.
2. For the selected photogate, there are two options: “blocked” and “unblocked” (for the landing
pad/time of flight accessory, the two options are “Off” and “On”).
a. If you choose “blocked”, that means the timer will start when the photogate is first
blocked (for the landing pad, “Off” means that the timer will start when the landing pad
is first hit).
b. If you choose “unblocked”, that means the timer will start when the photogate is first
unblocked (after being blocked).
3. Next, choose the photogate you want to use to stop the timer. Choose “blocked” or “unblocked”
(or “Off” or “On” for the landing pad) depending on what state you want the photogate to be in
when the timer is stopped.
Note: If you want to ensure that the photogate is blocked multiple times before stopping the timer,
simply add additional “blocked” commands prior to the last command. For example, if you
choose to “block” the photogate three times, the timer will start when the photogate is first
blocked and continue timing until the photogate is blocked twice more.
4. Change the label to something that indicates the time you’ve set up, like “Time between gates”
(it isn’t crucial that you do so, since you already know how the timer has been set up, but it
helps when referring back to it later, especially if you have set up multiple timers).
5. For additional timer setups, click “New” to create the instructions for those additional timers.
6. Click “Done”
In order to see the timing measurements, drag the “Table” icon (see bottom left part of the screen,
under “Display”) onto each timing measurement (indicated by icons in the top left part of the
screen, under “Data”).
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Note: The table contains two columns of data. Only one column indicates the time as requested
(typically the column on the right). The other column indicates the time since the timing
mechanism has started.
Click on the Start icon to start the timer.
Once the timing mechanism is started on the computer, you can continue to make multiple
measurements and the computer will continue to determine the time each time the block/unblock
sequence as specified is completed. You do not need to stop and restart the computer timing to get
another time measurement.
Click on the Stop icon to stop the timer.