Product number: HTM71

Compact, bench top apparatus to demonstrate the principle of operation of various centrifugal force governors. A motor driven vertical shaft has a chuck mounting which allows the easy attachment of the three governor mechanisms supplied. The shaft is speed controlled and the speed displayed on the front panel.


Three governors are supplied: Porter, Proell and Hartnell. Each governor is fully assembled, ready for testing. The Porter and Proell governors incorporate governor masses that can be removed to vary the rotating mass. Sleeve weights can also be added to these two governors using the slotted weights provided. The slotted weights are profiled not to come off during testing. The Hartnell governor incorporates a compression spring. This controls the movement of the central sleeve, by adjusting the spring tension using the adjustment knob on the vertical shaft. The vertical stroke of each governor can be measured using the increments on each of the governor shafts.
A transparent safety cover keeps rotating parts away from the students. A cut-off micro switch ensures the power to the motor is removed if the safety cover is not present.

Specifications and resources

Porter Governor radial travel range: 80….100mm (approximately)
Proell Governor radial travel range: 75….100mm (approximately)
Hartnell Spring rates: 0.39N/mm and 0.97N/mm (approximately)
Porter and Proell Sleeve masses: 58g (approximately)
Porter and Proell masses: 157g (approximately)
Hartnell masses: 118g (approximately)
Hartnell mass adjustment range: 20mm (approximately)
3mm increment indications on vertical shafts