Go Direct® Photogate (GDX-VPG)
Specifications and User Guide


  • Primary Test: Is the unit powered on or connected to a USB power source?
  • Secondary Test: Connect the Photogate to the data-collection program. Confirm that the Photogate has been identified by the program, and then use your hand to block and unblock the gate to confirm that the Photogate is working.
  • If the Photogate is not working with your Picket Fence, make sure that the protective plastic covering the picket fence has been removed.


Vernier Photogate with Picket Fence:


  • Infrared source: Peak at 880 nm
  • Output is high and LED off for unblocked gate
  • Output is low and LED on for blocked gate


  • It is not necessary to calibrate this sensor.

If the sensor can be turned on when connected by USB but not when disconnected from USB, it is likely that the battery just needs to be charged. In this case, charge the sensor for several hours and try again. If, however, the sensor won’t turn on regardless of whether the USB cable is connected or not, and you are confident that the USB cable is good by having tested it on another sensor, then the battery has likely reached its end of life and can no longer hold a charge. In this state, the sensor cannot be used even if connected by USB, so the battery will need to be replaced. The rechargeable battery in this sensor is covered by a one year warranty but should last two to five years in typical use. Note that if the battery is less than one year old and the sensor cannot be turned on even when connected by a working USB cable, another possibility is that the USB port is bad. In this case, contact Vernier technical support for assistance.