Quick Answer: The Governors apparatus is a base unit with a variable-speed motor that drives three governors in turn: Proell, Porter and Hartnell. A sensor measures how far each governor sleeve lifts as the speed rises.
Last updated: October 2026
Key Features
Variable-speed motor in the base unit drives each of the three governors
Porter and Proell governors lift the sleeve against gravity; the Hartnell governor lifts it against a compression spring
Hartnell governor arm length and rotating mass are adjustable
Sensor measures sleeve position (lift)
Motor control with direction, coarse and fine speed adjustment and press-to-stop
Clear dome with an interlock that cuts power to the motor
Technical Specifications
Specification
Value
Governors
Proell, Porter, Hartnell
Drive
Variable-speed motor in base unit
Display
Multi-line: speed in rev/min and rad/s, sleeve lift
Controls
Direction, coarse and fine speed, press to stop
Guard
Clear dome with power interlock
About This Product
Each governor uses rotating masses and levers to raise a sleeve as speed increases. Students record sleeve lift against speed for the gravity-loaded Porter and Proell designs and the spring-loaded Hartnell design, then change the Hartnell arm length and mass to see how the characteristic shifts.
Frequently Asked Questions
Which governors are included?
Three governors: Proell, Porter and Hartnell, each driven by the variable-speed motor in the base unit.
What does the display show?
Governor speed in revolutions per minute and radians per second, and the sleeve lift.
