PASPORT Rotary Motion Sensor - PS-2120A



Our Rotary Motion Sensor may be the most useful sensor in physics! Use it to study optics, dynamics, centripetal force, motion of a pendulum and many other topics. Measures position, velocity and acceleration (angular and linear) with incredible (0.09 º) resolution and accuracy. Higher maximum spin rate (30 rev/sec) allows students to perform a full range of motion experiments.

  • Measures magnitude and direction of motion.
  • Ball bearings minimize friction and provide mechanical support to rotating objects.

Typical Applications

  • Verify conservation of angular momentum
  • Calculate rotational inertia of disk ring and point mass
  • Measure displacement velocity and acceleration of a cart on a track
  • Conduct quantitative analysis of simple harmonic motion
  • Measure acceleration of a cart caused by a mass hung over a pulley


  • Three-step pulley (10, 29 and 48 mm diameter)
  • Rod clamp for mounting in almost any orientation


Three-step Pulley
  • 10, 29 and 48 mm diameter
Sensor Dimensions
  • 10 cm x 5 cm x 3.75 cm, 6.35 mm diameter shaft
  • +/- 0.09°/ 0.0078 mm
  • 0.02 mm (linear) and 0.09° (angular)(4,000 points per revolution)
Rotational Resolution
  • 0.00157 radian
Maximum rotation rate
  • 30 revolutions per second
Optical Encoder
  • Bidirectional, indicates direction of motion; 4000 divisions/rev

Buying Guide

Linear Motion Accessory
Linear Motion Accessory   CI-6688A

Interface Required

To use this product you need a PASCO interface. 

New to probeware or have questions about  sensors or interfaces? Contact Teacher and Technical Support.  We're here to help!

Software Required

SPARKvue software or PASCO Capstone software may be used. PASCO Capstone is available for Mac and Windows. SPARKvue is available for Mac, Windows, iOS, Android and Chromebooks.

Learn more about Bluetooth Compatibility.