Digital Photogate Timer System

Product Code: ME-9403A


PASCO Photogates and Digital Timers are used in thousands of physics labs throughout the world because they are rugged and simple to operate. This system combines the Digital Photogate Timer with an Accessory Photogate. The Accessory Photogate plugs directly into the Photogate Timer to produce synced responses. In Pulse Mode, the Accessory Photogate measures the time it takes for an object to travel between two photogates. In Gate Mode, it measures the velocity of an object as it passes through the first photogate, and then again when it passes through the second photogate.

Compatible with these PASCO products:

  • Time-of-Flight Accessory
  • Freefall Timer
  • Laser Switch


  • Powered by 4 C batteries (not included) or the 9V AC adapter (included)
  • Simply turn it on and begin collecting measurements
  • 0.1 ms resolution and 0.01% accuracy
  • Manual includes ten ready-to-use experiments
  • Timer serves as the base
  • Memory Function allows two measurements to be made in rapid succession, such as pre-collision and post-collision velocities
  • Two Photogates for measuring elapsed time between gate interferences


  • Instantaneous vs Average Velocity
  • Kinematics on an Inclined Plane
  • Speed of a Projectile
  • Newton’s Second Law
  • The Force of Gravity
  • Conservation of Momentum
  • Kinetic Energy
  • Conservation of Mechanical Energy
  • Elastic-Kinetic Energy
  • Pendulum Motion

What’s Included


Small parts. Not for children under 3 years.

Product Specifications

Modes Gate, pulse, pendulum, manual stopwatch
Resolution 0.1 ms (max time 19.9999 s)
Accuracy 0.05% of full range of the measured time ±1 digit
Display 5-1/2 digit, 10 mm high LCD
Memory Preserves displayed time while new time is measured
Photogate 6.5 cm wide; fully adjustable swivel mount; LED trigger indicator; fall time <10 ns; spacial resolution <1 mm
Inputs Accessory Photogates, or TTL-compatible signals; one photogate jack and a 9-V AC adapter jack (or four “C” size batteries) on back panel

Recommended Accessories

Time-of-Flight Accessory ME-6810A
Photogate & Pulley System ME-6838A
Freefall Adapter ME-9207B
Phone Jack Extender Cable PI-8117

Support Documents