Vernier Tech Info Library TIL #1623

Question

How do I set Logger Pro to use a photogate?

Answer

The best place to get started when using photogates is to choose File / Open, then go to the folder Experiment Files/Probes and Sensors/Photogates. Browse through those files. The goal when we set this folder up was to handle most common photogate timing situations. Some terminology used in naming the files needs to be explained:

"Gate" timing means timing how long a photogate is blocked.

"Pulse" timing means timing from the blocking of a photogate until the next blocking of a photogate.

"Motion Timer" means timing from leading edge to leading edge of a picket fence like object (object with a series of opaque bars, evenly spaced)

"Bounce" timing is meant for studying the bounce of a ball using a photogate mounted one ball diameter above the floor.

"Flash" timing measures how long a photogate is unblocked. It can be used to measure how long a camera shutter is open.

"Strobe" timing measures the time between unblocking events of the photogate. It can be used to check the timing of a strobe light, if the light replaces the IR source of the photogate.

"Collision" timing is like gate timing, but assumes two photogates are used to measure speeds before and after a collision. The moving objects are assumed to have "flags" of known length on them that go through the photogates.

"Pulley" timing assumes you have a Smart Pulley or a Supper Pulley mounted so that it blocks the photogate with its spokes as it turns.

"Pendulum" timing measures the period of a pendulum if mounted at the bottom of the swing.

"Jump" is set up to use with a laser beam along the floor pointed into one of our newer photogates which allows you to use the laser beam as the photogate beam. It measures the hang time of someone jumping.

We have a few labs using photogates in our Physics with Computers and Physics with Calculators books. There are experiment files for the Physics with Computer labs.

Note that if you are using photogates with calculators, you will need to use the DataGate program, which is a free download from:
http://www.vernier.com/calc/software/datagate.html

Created by: dvernier on February 07 2007
Last updated by: jhopkins on January 10 2008