One of the most useful devices for studying motion and timing, we offer two different photogate sensors that work with our software and two standalone options.

About Photogates

Photogates are a staple of every physics lab, used to teach students fundamental concepts about measuring time intervals and calculating speed and acceleration from their measurements. Physics teachers prefer photogates over traditional stopwatches due to their increased accuracy. Photogates are a timing device that measure times of the changes in state of an infrared beam that is blocked by a flag of known length, as well as the times the beam is unblocked. Using the flag length, and the blocked time, students can calculate speed. The smaller the flag length, the more 'instantaneous' the measurement becomes. Using a "Picket Fence" (a card with multiple flags), students can calculate acceleration. Photogates can also measure the rotation of a pulley with wide enough spokes that act as 'flags' to block the photogate's infrared beam.

Studying collisions. Shown is a Smart Gate with a Photogate Head daisy chained to it. Both are attached to a dynamics track using photogate brackets and the PAScars are equipped with Cart Picket Fences.

Using a Smart Gate and a Super Pulley to measure the acceleration on the PAScar.

Examples of physics experiments where photogates are used:

  • Determining g, acceleration due to gravity
  • Speed and Acceleration
  • Projectile Motion
  • Atwood's Machine
  • Collisions
  • Impulse and Momentum
  • Conservation of Momentum
  • Kinetic Energy
  • Simple Pendulum
  • Centripetal Acceleration

The Smart Gate

Smart Gate is an advancement in the design of the traditional photogate. It can be configured for all of the traditional uses of a standard photogate, and with its new features - experiments that a standard photogate cannot do. The Smart gate contains two photogates spaced 1.5 cm apart which gives it the most accurate measurement of speed over any traditional photogate. The rise and fall times of the Smart Gate measurements are faster than any other photogate, which results is more accurate timing. The Smart Gate also includes an auxiliary port for daisy chaining an extra Photogate or a Time of Flight Accessory. Use the built in photogate tape guide to use our Mylar Photogate Tape for measuring the speed and acceleration of fast moving objects that cannot travel through the Smart Gate Head. Smart Gate also includes a laser switch which enables a simple laser pointer to be used as the beam. This is useful for measuring timing of objects that are very large, or when you need a very long beam spacing.

Smart Gate has the same mounting footprint as our traditional photogate head, and is compatible with all of PASCO's photogate compatible apparatus.

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Smart Gate Products:

Smart Gate


Photogate that can be connected to any PASPORT interface, has auxiliary port to daisy chain gates, double beams for accurate speed measurement, and a special photogate tape slot.

  • Two Photogates Spaced 1.5 cm
  • Photogate Tape Guide
  • Laser Switch
  • Auxiliary Port
  • Includes Mounting rod,
  • PASPort extension cable

Projectile Launcher Smart Gate System


Study projectile motion and measure speeds accurately with the system containing the mini launcher and Smart gate.

The Projectile Launcher Smart Gate System combines our mini launcher and the Smart Gate along with the mounting brackets and table clamp to create a complete system to study projectile motion while accurately measuring the initial velocity.

Smart Gate Compatibility:

Smart Gate is directly compatible with PASPort interfaces (Except the Xplorer GLX and SPARK Science Learning System).

The Photogate Head

Originally designed as part of PASCO's original line of ScienceWorkshop sensors, the Photogate Heads are compatible with the 550 & 850 Universal Interfaces, legacy SW interfaces, and require the Digital Adapter to connect to PASPort interfaces such as the AirLink

The Photogate head can also be daisy chained to a Smart Gate.


PASCO's Photogate Head provides very accurate signals for timing. When combined into systems, even more timing applications can be measured.

The Photogate Head is available by itself or packaged with either a Photogate Stand or a Smart Pulley

Photogates and Fences -- Dynamics Systems


When used with the computer for data recording, displaying and analysis, this photogate/pulley timing system can provide a wide range of time, speed and velocity measurements.

For use with PASCO dynamics systems.

PASPORT Digital Adapter


The Digital Adapter allows ScienceWorkshop analog sensors to be connected and used with PASPORT interfaces.

Required if using a PASPORT interface with one or two Photogate Heads.

Standalone options

If you don't plan to use PASCO software or would just prefer an independent system, the Digital Photogate Timer Systems and Smart Timer Systems are available.

The Digital Timer System is a complete system that is simple and reliable with high resolution. It has simple onboard memory to record two times.

The Smart Timer System is a standalone timer that can control one or two of our photogate heads. It is available separately (with included picket fences) or as a complete system.

The Smart Timer has simple setup buttons for all of the most common uses of a photogate including picket fences, pendulums, collisions, dual gates pulleys and more.

Photogate Timers

The Photogate Timer is an accurate and versatile digital timer for the student laboratory. When combined with an accessory photogate, measure speed, velocity, and more.

Smart Timer System

Device and system provides the most versatile, cost-effective, portable way for making time, speed, acceleration, and count measurements.

Smart Gate and Photogate Accessories

Picket Fence


A rectangular piece of clear plastic with evenly spaced opaque bands.

Cart Picket Fences (2 Pack) -- IDS


Replacement photogate fences that mount on Dynamics Carts.

Photogate Tape (30 m)


30m roll of replacement tape for the Photogate Tape Set (ME-6664). Standard 5 cm band spacing.

Photogate Pendulum Set


Set of four pendula (brass, plastic, wood, and aluminum) that are ideal for PASCO’s Photogate Head and Photogate Accessory in timing experiments.

Photogate Stand


Designed to hold an Accessory Photogate (ME-9204B).

Photogate Mounting Bracket


This bracket mounts one or two Photogate Heads or a Smart Gate on any PASCO Projectile Launcher.

For use with PASCO Projectile Launchers.

Time-of-Flight Accessory


Use with a Photogate to capture time of flight data. Timing starts when object passes through photogate and stops when object impacts this landing pad. For use with PASPORT and ScienceWorkshop Interfaces.

Photogate Brackets (2 Pack) -- IDS


The Photogate Bracket is designed to attach Photogate Head to PAStrack and Curved PAStrack.

Super Pulley


Low-friction design produces excellent results. The precision spacing of the 10 spokes makes it ideal for photogate monitoring.

Super Pulley with Clamp


Upgrade force tables and inclined planes with this pulley and clamp.

Atwood's Machine


Two Super Pulleys mounted on a long rod produce a classic, low-friction introduction to Newton's Second Law.

Apparatus commonly used with Smart Gates / Photogate Heads

Projectile Launcher


Launch plastic spheres up to 5 m with highly repeatable results.

PASCO Dynamics Systems

Choose from our carts and tracks options to meet your classroom needs.

Requires bracket for use with photogates.

Rotating Platform


The stable base and precision bearings is one major component of the Complete Rotational System (ME-8950A).

Centripetal Force Apparatus


Show students the relationships between centripetal force, velocity, radius and mass.