Rotary Motion Sensors
Rotary motion sensors, often referred to as rotary encoders or angular position sensors, are vital components in the realm of science and engineering, designed to measure and track the rotational movement of objects with precision. These sensors are employed to determine the angular displacement, speed, and direction of rotation of various mechanical components such as motors, shafts, and wheels.
In scientific applications, rotary motion sensors play a crucial role in tasks ranging from monitoring the movement of celestial bodies in astronomy to analyzing the biomechanics of joint motion in human physiology. They enable scientists and engineers to gather valuable data related to angular position and velocity, aiding in the development of cutting-edge technologies and the advancement of our understanding of the physical world.
In this guide, we’ll cover some of our available rotary sensors, platforms, and load cells:
How Do Rotary Motion Sensors Work?
Rotary motion sensors operate on the principle of measuring changes in angular position or rotation. They typically consist of a rotating disc or shaft, often connected to the object whose motion needs to be tracked, and a stationary component. Inside the sensor, there are various technologies employed to detect the rotation:
- Optical Encoders: Optical encoders use a light source and a patterned disc. As the disc rotates, the light passes through the pattern, and a sensor on the other side detects the changes in light intensity, translating them into angular position.
- Magnetic Encoders: Magnetic encoders employ magnets on the rotating shaft and magnetic sensors to measure changes in the magnetic field. The magnetic patterns change with rotation, allowing the sensor to determine the angular position.
- Resistive (Potentiometric) Sensors: These sensors use a resistive element and a wiper attached to the rotating shaft. As the shaft turns, the wiper's position changes, altering the resistance, which can be measured to determine the angle.
- Hall Effect Sensors: Hall effect sensors detect changes in magnetic fields. A magnet on the rotating shaft generates a magnetic field, and a Hall sensor measures the variations, providing information about the shaft's rotation.
- Capacitive Sensors: Capacitive sensors rely on changes in capacitance as the gap between plates (often on the rotating and stationary parts) changes with rotation. These changes in capacitance indicate the angular position.
Once these sensors detect changes in angular position, the data is usually converted into electrical signals, which can be processed by electronic circuits or microcontrollers. The resulting information can be used for a wide range of applications, from controlling the movement of machines to providing feedback for navigation systems or precise positioning in various industries and scientific fields.
To learn how PASCO rotary motion sensors work, visit our Knowledge Base: Principle of Operation - Rotary Motion Sensor.
Common Applications for Rotary Motion Sensors
- Newton’s Second Law for Rotation
- Centripetal Force on a Pendulum
- Rotational Dynamics
- Telescopes and Astronomy
- Polarization
- Ampere’s Law
- Aviation and Aerospace
- Industrial Automation
Students investigate Ampere’s Law with the Wireless Rotary Motion Sensor.
Wireless and PASPORT Rotary Motion Sensors demonstrating how a gyroscope works.
Wireless Rotary Motion Sensor
The Wireless Rotary Motion Sensor (PS-3220) offers a comprehensive solution for studying rotational dynamics. This versatile sensor enables the measurement of angle, angular velocity, angular acceleration, and their corresponding linear equivalents. With its included three-step pulley, students can explore the effects of different torques on the rotational motion of a rigid system, allowing for investigations into varying rates of acceleration; plus, the absence of wires and cables makes investigations like Ampere’s Law possible with the sensor able to move freely. The rod-mounting holes provide flexibility in sensor orientation for different experiments, ensuring adaptability to a wide range of classroom scenarios. This sensor seamlessly connects to devices via Bluetooth® or USB, enhancing accessibility and ease of data collection.
Its applications span critical physics concepts including the conservation of angular momentum, rotational inertia, centripetal acceleration, and torque, making it an indispensable tool for hands-on learning in physics demonstrations and labs.
Wireless Rotary Motion Sensor Features
- Angular Resolution: 0.18º
- Linear Resolution: 0.0157 mm (with 10 mm pulley radius)
- Three-step Pulley: 10 mm, 29 mm, and 48 mm diameter
- Shaft Diameter: 6.35 mm
- Maximum Rotation Rate: 30 rev/s
- Optical Encoder: 2000 divisions/rev, bidirectional
- Connectivity: USB and Bluetooth
- Memory Logging: >55,000 Data Points
- Rechargeable LiPo Battery
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Investigations with the Wireless Rotary Motion Sensor
Visit our Experiment Library to view a list of studies to do with your class.Software Required for the Wireless Rotary Motion Sensor
The Wireless Rotary Motion Sensor requires either SPARKvue or PASCO Capstone software for data collection and analysis. For more information on which software is right for your classroom, see our Software Comparison Guide.
Wireless Rotary Motion Sensor Compatible Accessories
The Wireless Rotary Motion Sensor needs to be plugged into a USB charger upon arrival before use. It can connect directly to your computer or device using Bluetooth. No interface is required. Use it in collaboration with the following PASCO products:
Rod Clamp for Rotary Motion Sensor
Replacement rod clamp for the Rotary Motion Sensor
Pendulum Accessory
This pendulum accessory converts a rotary motion sensor into a pendulum.
Rotational Inertia Accessory
Add the Rotational Inertia Accessory to a PASCO Rotary Motion Sensor (PS-3220 or PS-2120) to study the rotational inertia...
Mini Ballistic Pendulum Accessory
Turn your PASCO Launcher into a Ballistic Pendulum using the Rotary Motion Sensor.
PASPORT Rotary Motion Sensor
The PASPORT Rotary Motion Sensor (PS-2120A) is the older version of the Wireless Rotary Motion Sensor. It is a highly versatile and precise tool designed for measuring a wide range of rotational parameters with exceptional accuracy. This sensor is capable of measuring position, velocity, and acceleration, both angular and linear, providing a high-resolution output of 4000 divisions per revolution. With a maximum spin rate of 30 revolutions per second, it offers the capability to analyze dynamic rotational phenomena.
The sensor operates by detecting angle changes using an optical encoder which interrupts the light beam 4000 times per revolution of its shaft. Its design features a 6.35 mm diameter dual ball-bearing shaft, extending from both sides, allowing for easy attachment of objects. The included three-step pulley and versatile rod clamp enable diverse experimental setups. It also has built-in storage for the hex key needed to remove the rod clamp.
Applications for this sensor range from verifying the conservation of angular momentum to calculating the rotational inertia of various objects, measuring displacement, velocity, and acceleration of carts on tracks, conducting quantitative analysis of simple harmonic motion, and accurately measuring angular acceleration in systems with constant torque. With its exceptional capabilities and adaptability, the PASPORT Rotary Motion Sensor is an invaluable tool for advanced physics experiments and investigations.
PASPORT Rotary Motion Sensor Features
- Three-step Pulley: 10 mm, 29 mm, and 48 mm diameters
- Sensor Dimensions: 10 cm x 5 cm x 3.75 cm, 6.35 mm diameter shaft
- Rotary Motion Resolution: 0.09º (0.00157 rad)
- Linear Motion Resolution: 0.0078 mm
- Maximum Rotation Rate: 30 revs/sec
- Rotary Motion Optical Encoder: Bidirectional to indicate the direction of motion; 4000 divisions/rev
Watch the video below for an overview:
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Investigations with the PASPORT Rotary Motion Sensor
Visit our Experiment Library to view a list of studies to do with your class.Software Required for PASPORT Rotary Motion Sensor
The PASPORT Rotary Motion Sensor requires either SPARKvue or PASCO Capstone software for data collection and analysis. For more information on which software is right for your classroom, see our Software Comparison Guide.
Compatible Interfaces for the PASPORT Rotary Motion Sensor: 550 Universal Interface, 850 Universal Interface, Airlink, Sparklink Air, SPARK LXi2 Datalogger
A PASCO interface is required to connect the PASPORT Rotary Motion Sensor to your computer or device. We recommend the following options. For a breakdown of features, capabilities, and additional options, see our Interface Comparison Guide.
PASPORT Rotary Motion Sensor Compatible Accessories
Rotational Inertia Accessory
Includes a disk and a ring to support several experiments in rotational inertia. A component of PASCO’s Complete Rotational...
3-Step Pulley for Rotary Motion Sensor
An extra 3-step Pulley for PASCO’s Rotary Motion Sensors.
Mini Ballistic Pendulum Accessory
Turn your PASCO Launcher into a Ballistic Pendulum using the Rotary Motion Sensor.
Rotational Inertia Accessory
Add the Rotational Inertia Accessory to a PASCO Rotary Motion Sensor (PS-3220 or PS-2120) to study the rotational inertia...
ScienceWorkshop Rotary Motion Sensor
The ScienceWorkshop Rotary Motion Sensor (CI-6538) is a versatile and precise tool designed for a wide range of physics experiments. This sensor can measure both angle and angular velocity or distance and linear velocity using either a rack or a pulley. Notably, it is bi-directional, providing information about the direction of motion, adding valuable insights to experiments. The sensor boasts a 6.35 mm diameter dual ball-bearing shaft that extends from both sides, offering an ideal platform for rotational experiments. Its adaptable design includes a rod clamp, allowing the sensor to be mounted in almost any orientation. Additionally, a three-step pulley and a mount for the PASCO Super Pulley facilitate torque experiments. The heart of the sensor is an optical encoder, ensuring high precision with no drift or cumulative error. Users can select a resolution of either 1° or 0.25°, making it a reliable and versatile tool for a wide range of applications, including studies on conservation of angular momentum, rotational inertia of various objects, force vs. displacement, simple harmonic motion, and more. The Rotary Motion Sensor is a valuable resource for hands-on physics experimentation, delivering accurate and consistent results.
ScienceWorkshop Rotary Motion Sensor Features
- Resolution: 1º/0.087 mm, 0.25º/0.022 mm
- Maximum Speed: 13 rev/sec at 1º resolution (360 data points/rev)
- Optical Encoder: Bidirectional, indicates direction of motion
- Connector: Dual stereo phone plug for 850, 550, and ScienceWorkshop Interfaces
- Three-step Pulley: 10 mm, 29 mm, and 48 mm diameter
- Dimensions: 10 cm x 5 cm x 3.75 cm, 6.35 mm diameter shaft
Software Required for the ScienceWorkshop Rotary Motion Sensor
The ScienceWorkshop Rotary Motion Sensor requires either SPARKvue or PASCO Capstone software for data collection and analysis. For more information on which software is right for your classroom, see our Software Comparison Guide.
Compatible Interfaces for the ScienceWorkshop Rotary Motion Sensor: 550 Universal Interface, 850 Universal Interface, Airlink, Sparklink Air, SPARK LXi2 Datalogger
A PASCO interface is required to connect the ScienceWorkshop Rotary Motion Sensor to your computer or device. Both the 550 and 850 include both digital and analog inputs to accept ScienceWorkshop sensors directly. For a breakdown of features, capabilities, and additional options, see our Interface Comparison Guide.
For more information about ScienceWorkshop, see our Using ScienceWorkshop Sensors Guide.
We recommend the following options:
ScienceWorkshop Rotary Motion Sensor Compatible Accessories
The ScienceWorkshop Rotary Motion Sensor needs to be plugged into a charger upon arrival before use. Use it in collaboration with the following PASCO products:
Linear Motion Accessory
Slides through a special slot in the Rotary Motion Sensor and allows you to measure short linear distances.
Chaos/Driven Harmonic Accessory
Allows students to study the behavior of a physical pendulum in either harmonic or chaotic motion.
Pendulum Accessory
This pendulum accessory converts a rotary motion sensor into a pendulum.
Mini Ballistic Pendulum Accessory
Turn your PASCO Launcher into a Ballistic Pendulum using the Rotary Motion Sensor.
Comparison Table
Sensor |
Wireless Rotary Motion Sensor (PS-3220)
|
PASPORT Rotary Motion Sensor (PS-2120A)
|
ScienceWorkshop Rotary Motion Sensor (CI-6538)
|
Interface |
✗ No Interface Required |
|
|
Dimension |
6.35 mm diameter shaft |
10 cm x 5 cm x 3.75 cm, 6.35 mm diameter shaft |
10 cm x 5 cm x 3.75 cm, 6.35 mm diameter shaft |
Optical Encoder |
Bidirectional to indicate the direction of motion 2000 divisions/rev |
Bidirectional to indicate the direction of motion 4000 divisions/rev |
Bidirectional to indicate the direction of motion |
Resolution (mm) |
Angular Resolution: 0.18º Linear Resolution: 0.0157 mm (with 10 mm pulley radius) |
Angular Resolution: 0.09º (0.00157 rad) Linear Resolution: 0.0078 mm |
1°/0.087 mm 0.25°/0.022 mm (software selectable) |
Maximum Rotation Rate |
30 rev/sec |
30 rev/sec |
13 rev/sec at 1° resolution (360 data points/revolution) 3.25 rev/sec at 0.25° resolution (1440 data points/revolution) |
Features |
|
No battery needed |
No battery needed |
Related Product Bundles
Explore bundles that pair rotary motion sensors with other PASCO products for your physics and engineering labs!
Ballistic Pendulum - Wireless
Use conservation of energy and conservation of momentum to determine the muzzle velocity of a projectile.
Heat Engine Cycle - Wireless
Measure the efficiency of a real heat engine and compare it to the efficiency of an ideal heat engine.
Comprehensive 850 Mechanics Bundle
This bundle includes all the equipment and sensors needed to perform the experiments in the Comprehensive 850 Mechanics System Experiment Manual.
Comprehensive 850 Physics System
This product includes a complete set of physics labs and equipment designed for use with the 850 Universal Interface and PASCO Capstone software.
Additional Resources
If you have additional questions regarding our equipment or software, contact PASCO Technical Support. We're here to help.