Attention: Safety Recall of Vernier Go Direct Charge Station. Click to learn more.


Sharing ideas and inspiration for engagement, inclusion, and excellence in STEM

Building a Better Mousetrap – A New Vernier Photogate

We are excited to announce a new sensor for physics—Go Direct Photogate. With our first-ever wireless photogate, you get better-than-stopwatch timing accuracy of a cart traveling eight or more meters without having to run wires between the gates. And that is not even its best feature.

Go Direct® Photogate is actually three photogates in one. The interior arms of the photogate include two photodiodes. This double-gate design measures velocity more accurately in comparison to single-gate photogates. The known separation of the gates makes it possible to measure speed without concern for the object’s geometry or knowing its dimensions. The direction of motion is indicated by positive or negative velocities determined by the order in which the internal gates are blocked. For objects that have two or more flags, the acceleration of the object through the gate can be reported as well. You can also use the internal gates independently for experiments that utilize traditional photogate modes, such as motion and pendulum timing.

The third photogate is a laser gate that you can use with a laser pointer (not included) to make a single gate that is any width. This is useful when dealing with larger objects that cannot pass between the interior arms of the photogate.

You can use Go Direct Photogate with all of our existing photogate accessories including the Laser, Picket Fence, Cart Picket Fence, Ultra Pulley Attachment, and Bar Tape. (Go Direct Photogate includes a built-in Bar Tape guide located on the sensor). You can mount Go Direct Photogate on our dynamics track using the photogate brackets included with the cart and track systems without any additional parts or adapters. You can also mount Go Direct Photogate to our Centripetal Force Apparatus.

There are two optional accessory cables for the Go Direct Photogate, each sold separately. Use a Go Direct Photogate Timing Cable to daisy-chain two Go Direct Photogates together. This configuration makes the two Go Direct Photogates work using a single clock, which can improve timing accuracy by up to 10 ms. Use the Go Direct Time of Flight Pad Cable to connect a Time of Flight Pad to a Go Direct Photogate for use in projectile motion experiments.

For more information about Go Direct Photogate, see

Share this Article